| Message ID | 20180906081920.32298-2-acelan.kao@canonical.com |
|---|---|
| State | New |
| Headers | show |
| Series | BugLink: https://bugs.launchpad.net/bugs/1727235 | expand |
On 06/09/18 09:19, AceLan Kao wrote: > BugLink: https://bugs.launchpad.net/bugs/1727235 > > The Dell AIO machines released after 2017 come with a UART interface > to communicate with the backlight scalar board. This driver creates > a standard backlight interface and talks to the scalar board through > UART. > > In DSDT this uart port will be defined as > Name (_HID, "DELL0501") > Name (_CID, EisaId ("PNP0501") > The 8250 PNP driver will be loaded by default, and this driver uses > "DELL0501" to confirm the uart port is a backlight interface and > leverage the port created by 8250 PNP driver to communicate with > the scalar board. > > v2: > 1. move struct uart_cmd to .c file > 2. make dell_uart_get_bl_power() inline > 3. add space to ternary operator "bl_cmd->cmd[2] = power ? 0 : 1;" > 4. check return value of kzalloc() > 5. add kzfree() > 6. check return value of backlight_device_register() > 7. check return value of filp_open() at init > v3: > 1. Fix compiling warning. > > Signed-off-by: AceLan Kao <acelan.kao@canonical.com> > --- > drivers/platform/x86/Kconfig | 14 + > drivers/platform/x86/Makefile | 1 + > drivers/platform/x86/dell-uart-backlight.c | 463 +++++++++++++++++++++ > drivers/platform/x86/dell-uart-backlight.h | 36 ++ > 4 files changed, 514 insertions(+) > create mode 100644 drivers/platform/x86/dell-uart-backlight.c > create mode 100644 drivers/platform/x86/dell-uart-backlight.h > > diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig > index b6ac37a5d06d..b6ce1a5b01e5 100644 > --- a/drivers/platform/x86/Kconfig > +++ b/drivers/platform/x86/Kconfig > @@ -199,6 +199,20 @@ config DELL_RBTN > To compile this driver as a module, choose M here: the module will > be called dell-rbtn. > > +config DELL_UART_BACKLIGHT > + tristate "Dell AIO UART Backlight driver" > + depends on SERIAL_8250 > + depends on ACPI > + ---help--- > + Say Y here if you want to support Dell AIO UART backlight interface. > + The Dell AIO machines released after 2017 come with a UART interface > + to communicate with the backlight scalar board. This driver creates > + a standard backlight interface and talks to the scalar board through > + UART to adjust the AIO screen brightness. > + > + To compile this driver as a module, choose M here: the module will > + be called dell_uart_backlight. > + > > config FUJITSU_LAPTOP > tristate "Fujitsu Laptop Extras" > diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile > index c32b34a72467..85329fd26afd 100644 > --- a/drivers/platform/x86/Makefile > +++ b/drivers/platform/x86/Makefile > @@ -22,6 +22,7 @@ obj-$(CONFIG_DELL_WMI_AIO) += dell-wmi-aio.o > obj-$(CONFIG_DELL_WMI_LED) += dell-wmi-led.o > obj-$(CONFIG_DELL_SMO8800) += dell-smo8800.o > obj-$(CONFIG_DELL_RBTN) += dell-rbtn.o > +obj-$(CONFIG_DELL_UART_BACKLIGHT) += dell-uart-backlight.o > obj-$(CONFIG_ACER_WMI) += acer-wmi.o > obj-$(CONFIG_ACERHDF) += acerhdf.o > obj-$(CONFIG_HP_ACCEL) += hp_accel.o > diff --git a/drivers/platform/x86/dell-uart-backlight.c b/drivers/platform/x86/dell-uart-backlight.c > new file mode 100644 > index 000000000000..eae075cfcadb > --- /dev/null > +++ b/drivers/platform/x86/dell-uart-backlight.c > @@ -0,0 +1,463 @@ > +/* > + * Dell AIO Serial Backlight Driver > + * > + * Copyright (C) 2017 AceLan Kao <acelan.kao@canonical.com> > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + */ > + > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/acpi.h> > +#include <linux/serial_8250.h> > +#include <linux/delay.h> > +#include <linux/backlight.h> > +#include <acpi/video.h> > + > +#include "dell-uart-backlight.h" > + > +struct dell_uart_backlight { > + struct device *dev; > + struct backlight_device *dell_uart_bd; > + struct mutex brightness_mutex; > + int line; > + int bl_power; > +}; > +struct uart_8250_port *serial8250_get_port(int line); > +struct tty_struct *tty; > +struct file *ftty; Should tty and ftty be static? > + > +unsigned int (*io_serial_in)(struct uart_port *p, int offset); > +int (*uart_write)(struct tty_struct *tty, const unsigned char *buf, int count); > +int (*uart_chars_in_buffer)(struct tty_struct *tty); > + > +static struct dell_uart_bl_cmd uart_cmd[] = { Would it make sense for uart_cmd to be also const? > + /* > + * Get Firmware Version: Tool uses this command to get firmware version. > + * Command: 0x6A 0x06 0x8F (Length:3 Type: 0x0A, Cmd:6 Checksum:0x8F) > + * Return data: 0x0D 0x06 Data checksum (Length:13,Cmd:0x06, > + * Data :F/W version(APRILIA=APR27-VXXX,PHINE=PHI23-VXXX), > + * checksum:SUM(Length and Cmd and Data)xor 0xFF . > + */ > + [DELL_UART_GET_FIRMWARE_VER] = { > + .cmd = {0x6A, 0x06, 0x8F}, > + .tx_len = 3, > + }, > + /* > + * Get Brightness level: Application uses this command for scaler to get brightness. > + * Command: 0x6A 0x0C 0x89 (Length:3 Type: 0x0A, Cmd:0x0C, Checksum:0x89) > + * Return data: 0x04 0x0C Data checksum > + * (Length:4 Cmd: 0x0C Data: brightness level checksum: SUM(Length and Cmd and Data)xor 0xFF) > + * brightness level which ranges from 0~100. > + */ > + [DELL_UART_GET_BRIGHTNESS] = { > + .cmd = {0x6A, 0x0C, 0x89}, > + .ret = {0x04, 0x0C, 0x00, 0x00}, > + .tx_len = 3, > + .rx_len = 4, > + }, > + /* Set Brightness level: Application uses this command for scaler to set brightness. > + * Command: 0x8A 0x0B Byte2 Checksum (Length:4 Type: 0x0A, Cmd:0x0B) > + * where Byte2 is the brightness level which ranges from 0~100. > + * Return data: 0x03 0x0B 0xF1(Length:3,Cmd:B,checksum:0xF1) > + * Scaler must send the 3bytes ack within 1 second when success, other value if error > + */ > + [DELL_UART_SET_BRIGHTNESS] = { > + .cmd = {0x8A, 0x0B, 0x0, 0x0}, > + .ret = {0x03, 0x0B, 0xF1}, > + .tx_len = 4, > + .rx_len = 3, > + }, > + /* > + * Screen ON/OFF Control: Application uses this command to control screen ON or OFF. > + * Command: 0x8A 0x0E Byte2 Checksum (Length:4 Type: 0x0A, Cmd:0x0E) where > + * Byte2=0 to turn OFF the screen. > + * Byte2=1 to turn ON the screen > + * Other value of Byte2 is reserved and invalid. > + * Return data: 0x03 0x0E 0xEE(Length:3,Cmd:E,checksum:0xEE) > + */ > + [DELL_UART_SET_BACKLIGHT_POWER] = { > + .cmd = {0x8A, 0x0E, 0x00, 0x0}, > + .ret = {0x03, 0x0E, 0xEE}, > + .tx_len = 4, > + .rx_len = 3, > + }, > +}; > + > +static int dell_uart_write(struct uart_8250_port *up, __u8 *buf, int len) > +{ > + int actual = 0; > + struct uart_port *port = &up->port; > + > + tty_port_tty_wakeup(&port->state->port); > + tty = tty_port_tty_get(&port->state->port); > + actual = uart_write(tty, buf, len); > + while (uart_chars_in_buffer(tty)) { > + udelay(10); > + } > + > + return actual; > +} > + > +static int dell_uart_read(struct uart_8250_port *up, __u8 *buf, int len) > +{ > + int i, retry; > + unsigned long flags; > + > + spin_lock_irqsave(&up->port.lock, flags); > + for (i = 0; i < len; i++) { > + retry = 10; > + while (!(io_serial_in(&up->port, UART_LSR) & UART_LSR_DR)) { > + if (--retry == 0) > + break; > + mdelay(20); > + } > + > + if (retry == 0) > + break; > + buf[i] = io_serial_in(&up->port, UART_RX); > + } > + spin_unlock_irqrestore(&up->port.lock, flags); > + > + return i; > +} > + > +static void dell_uart_dump_cmd(const char *func, const char *prefix, > + const char *cmd, int len) > +{ > + char buf[80]; > + > + snprintf(buf, 80, "dell_uart_backlight:%s:%s", func, prefix); > + if (len != 0) > + print_hex_dump_debug(buf, DUMP_PREFIX_NONE, > + 16, 1, cmd, len, false); > + else > + pr_debug("dell_uart_backlight:%s:%sNULL\n", func, prefix); > + > +} > + > +/* > + * checksum: SUM(Length and Cmd and Data)xor 0xFF) > + */ > +static unsigned char dell_uart_checksum(unsigned char *buf, int len) > +{ > + unsigned char val = 0; > + > + while (len-- > 0) > + val += buf[len]; > + > + return val ^ 0xff; > +} > + > +/* > + * There is no command to get backlight power status, > + * so we set the backlight power to "on" while initializing, > + * and then track and report its status by bl_power variable > + */ > +static int inline dell_uart_get_bl_power(struct dell_uart_backlight *dell_pdata) > +{ > + return dell_pdata->bl_power; > +} > + > +static int dell_uart_set_bl_power(struct backlight_device *bd, int power) > +{ > + struct dell_uart_bl_cmd *bl_cmd = > + &uart_cmd[DELL_UART_SET_BACKLIGHT_POWER]; > + struct dell_uart_backlight *dell_pdata = bl_get_data(bd); > + struct uart_8250_port *uart = serial8250_get_port(dell_pdata->line); > + int rx_len; > + > + if (power != FB_BLANK_POWERDOWN) > + power = FB_BLANK_UNBLANK; > + > + bl_cmd->cmd[2] = power ? 0 : 1; > + bl_cmd->cmd[3] = dell_uart_checksum(bl_cmd->cmd, bl_cmd->tx_len - 1); > + > + dell_uart_dump_cmd(__func__, "tx: ", bl_cmd->cmd, bl_cmd->tx_len); > + > + if (mutex_lock_killable(&dell_pdata->brightness_mutex) < 0) { > + pr_debug("Failed to get mutex_lock"); > + return 0; > + } > + > + dell_uart_write(uart, bl_cmd->cmd, bl_cmd->tx_len); > + rx_len = dell_uart_read(uart, bl_cmd->ret, bl_cmd->rx_len); > + > + mutex_unlock(&dell_pdata->brightness_mutex); > + > + dell_uart_dump_cmd(__func__, "rx: ", bl_cmd->ret, rx_len); > + > + bd->props.power = power; > + dell_pdata->bl_power = power; > + > + return 0; > +} > + > +static int dell_uart_get_brightness(struct backlight_device *bd) > +{ > + struct dell_uart_bl_cmd *bl_cmd = &uart_cmd[DELL_UART_GET_BRIGHTNESS]; > + struct dell_uart_backlight *dell_pdata = bl_get_data(bd); > + struct uart_8250_port *uart = serial8250_get_port(dell_pdata->line); > + int rx_len, brightness = 0; > + > + dell_uart_dump_cmd(__func__, "tx: ", bl_cmd->cmd, bl_cmd->tx_len); > + > + if (mutex_lock_killable(&dell_pdata->brightness_mutex) < 0) { > + pr_debug("Failed to get mutex_lock"); > + return 0; > + } > + > + dell_uart_write(uart, bl_cmd->cmd, bl_cmd->tx_len); > + rx_len = dell_uart_read(uart, bl_cmd->ret, bl_cmd->rx_len); > + > + mutex_unlock(&dell_pdata->brightness_mutex); > + > + dell_uart_dump_cmd(__func__, "rx: ", bl_cmd->ret, rx_len); > + > + brightness = (unsigned int)bl_cmd->ret[2]; > + > + return brightness; > +} > + > +static int dell_uart_update_status(struct backlight_device *bd) > +{ > + struct dell_uart_bl_cmd *bl_cmd = &uart_cmd[DELL_UART_SET_BRIGHTNESS]; > + struct dell_uart_backlight *dell_pdata = bl_get_data(bd); > + struct uart_8250_port *uart = serial8250_get_port(dell_pdata->line); > + int rx_len; > + > + bl_cmd->cmd[2] = bd->props.brightness; > + bl_cmd->cmd[3] = dell_uart_checksum(bl_cmd->cmd, bl_cmd->tx_len - 1); > + > + dell_uart_dump_cmd(__func__, "tx: ", bl_cmd->cmd, bl_cmd->tx_len); > + > + if (mutex_lock_killable(&dell_pdata->brightness_mutex) < 0) { > + pr_debug("Failed to get mutex_lock"); > + return 0; > + } > + > + dell_uart_write(uart, bl_cmd->cmd, bl_cmd->tx_len); > + rx_len = dell_uart_read(uart, bl_cmd->ret, bl_cmd->rx_len); > + > + mutex_unlock(&dell_pdata->brightness_mutex); > + > + dell_uart_dump_cmd(__func__, "rx: ", bl_cmd->ret, rx_len); > + > + if (bd->props.power != dell_uart_get_bl_power(dell_pdata)) > + dell_uart_set_bl_power(bd, bd->props.power); > + > + return 0; > +} > + > +static int dell_uart_get_scalar_status(struct dell_uart_backlight *dell_pdata) > +{ > + struct dell_uart_bl_cmd *bl_cmd = &uart_cmd[DELL_UART_GET_SCALAR]; > + struct uart_8250_port *uart = serial8250_get_port(dell_pdata->line); > + int rx_len, status = 1; /* assume the scalar IC controls backlight if the command failed */ > + > + dell_uart_dump_cmd(__func__, "tx: ", bl_cmd->cmd, bl_cmd->tx_len); > + > + if (mutex_lock_killable(&dell_pdata->brightness_mutex) < 0) { > + pr_debug("Failed to get mutex_lock"); > + return 0; > + } > + > + dell_uart_write(uart, bl_cmd->cmd, bl_cmd->tx_len); > + rx_len = dell_uart_read(uart, bl_cmd->ret, bl_cmd->rx_len); > + > + mutex_unlock(&dell_pdata->brightness_mutex); > + > + dell_uart_dump_cmd(__func__, "rx: ", bl_cmd->ret, rx_len); > + > + if (rx_len == 4) > + status = (unsigned int)bl_cmd->ret[2]; > + > + return status; > +} > + > +static int dell_uart_show_firmware_ver(struct dell_uart_backlight *dell_pdata) > +{ > + struct dell_uart_bl_cmd *bl_cmd = &uart_cmd[DELL_UART_GET_FIRMWARE_VER]; > + struct uart_8250_port *uart = serial8250_get_port(dell_pdata->line); > + int rx_len = 0, retry = 10; > + > + dell_uart_dump_cmd(__func__, "tx: ", bl_cmd->cmd, bl_cmd->tx_len); > + > + if (mutex_lock_killable(&dell_pdata->brightness_mutex) < 0) { > + pr_debug("Failed to get mutex_lock"); > + return -1; > + } > + > + dell_uart_write(uart, bl_cmd->cmd, bl_cmd->tx_len); > + while (retry-- > 0) { > + /* first byte is data length */ > + dell_uart_read(uart, bl_cmd->ret, 1); > + rx_len = (int)bl_cmd->ret[0]; > + if (bl_cmd->ret[0] > 80 || bl_cmd->ret[0] <= 0) { Minor quibble, bl_cmd->ret is unsigned char, so it can never be < than zero. Perhaps bl_cmd->ret[0] == 0 is better > + pr_debug("Failed to get firmware version\n"); > + if (retry == 0) { > + mutex_unlock(&dell_pdata->brightness_mutex); > + return -1; > + } > + msleep(100); > + continue; > + } > + > + dell_uart_read(uart, bl_cmd->ret+1, rx_len-1); > + break; > + } > + mutex_unlock(&dell_pdata->brightness_mutex); > + > + dell_uart_dump_cmd(__func__, "rx: ", bl_cmd->ret, rx_len); > + > + pr_debug("Firmare str(%d)= %s\n", (int)bl_cmd->ret[0], bl_cmd->ret+2); > + return rx_len; > +} > + > +static const struct backlight_ops dell_uart_backlight_ops = { > + .get_brightness = dell_uart_get_brightness, > + .update_status = dell_uart_update_status, > +}; > + > +static int dell_uart_startup(struct dell_uart_backlight *dell_pdata) > +{ > + struct uart_8250_port *uartp; > + struct uart_port *port; > + > + dell_pdata->line = 0; > + uartp = serial8250_get_port(dell_pdata->line); > + port = &uartp->port; > + tty = port->state->port.tty; > + io_serial_in = port->serial_in; > + uart_write = tty->driver->ops->write; > + uart_chars_in_buffer = tty->driver->ops->chars_in_buffer; > + > + return 0; > +} > + > +static int dell_uart_bl_add(struct acpi_device *dev) > +{ > + struct dell_uart_backlight *dell_pdata; > + struct backlight_properties props; > + struct backlight_device *dell_uart_bd; > + > + dell_pdata = kzalloc(sizeof(struct dell_uart_backlight), GFP_KERNEL); > + if (!dell_pdata) { > + pr_debug("Failed to allocate memory for dell_uart_backlight\n"); > + return -1; > + } > + dell_pdata->dev = &dev->dev; > + dell_uart_startup(dell_pdata); > + dev->driver_data = dell_pdata; > + > + mutex_init(&dell_pdata->brightness_mutex); > + > + if (!dell_uart_get_scalar_status(dell_pdata)) { > + udelay(50); > + /* try another command to make sure there is no scalar IC */ > + if (dell_uart_show_firmware_ver(dell_pdata) <= 0) { > + pr_debug("Scalar is not in charge of brightness adjustment.\n"); > + kzfree(dell_pdata); > + return -1; > + } > + } > + > + memset(&props, 0, sizeof(struct backlight_properties)); > + props.type = BACKLIGHT_PLATFORM; > + props.max_brightness = 100; > + > + dell_uart_bd = backlight_device_register("dell_uart_backlight", > + &dev->dev, > + dell_pdata, > + &dell_uart_backlight_ops, > + &props); > + if (IS_ERR(dell_uart_bd)) { > + kzfree(dell_pdata); > + pr_debug("Backlight registration failed\n"); > + return -1; > + } > + > + dell_pdata->dell_uart_bd = dell_uart_bd; > + > + dell_uart_set_bl_power(dell_uart_bd, FB_BLANK_UNBLANK); > + dell_uart_bd->props.brightness = 100; > + backlight_update_status(dell_uart_bd); > + > + /* unregister acpi backlight interface */ > + acpi_video_set_dmi_backlight_type(acpi_backlight_vendor); > + > + return 0; > +} > + > +static int dell_uart_bl_remove(struct acpi_device *dev) > +{ > + struct dell_uart_backlight *dell_pdata = dev->driver_data; > + > + backlight_device_unregister(dell_pdata->dell_uart_bd); > + kzfree(dell_pdata); > + > + return 0; > +} > + > +static int dell_uart_bl_suspend(struct device *dev) > +{ > + filp_close(ftty, NULL); > + return 0; > +} > + > +static int dell_uart_bl_resume(struct device *dev) > +{ > + ftty = filp_open("/dev/ttyS0", O_RDWR | O_NOCTTY | O_NDELAY, 0); > + return 0; > +} > + > +static SIMPLE_DEV_PM_OPS(dell_uart_bl_pm, dell_uart_bl_suspend, dell_uart_bl_resume); > + > +static const struct acpi_device_id dell_uart_bl_ids[] = { > + {"DELL0501", 0}, > + {"", 0}, > +}; > + > +static struct acpi_driver dell_uart_backlight_driver = { > + .name = "Dell AIO serial backlight", > + .ids = dell_uart_bl_ids, > + .ops = { > + .add = dell_uart_bl_add, > + .remove = dell_uart_bl_remove, > + }, > + .drv.pm = &dell_uart_bl_pm, > +}; > + > +static int __init dell_uart_bl_init(void) > +{ > + ftty = filp_open("/dev/ttyS0", O_RDWR | O_NOCTTY | O_NDELAY, 0); > + if (IS_ERR(ftty)) { > + pr_debug("cannot open /dev/ttyS0\n"); > + return -EINVAL; > + } > + > + return acpi_bus_register_driver(&dell_uart_backlight_driver); > +} > + > +static void __exit dell_uart_bl_exit(void) > +{ > + filp_close(ftty, NULL); > + > + acpi_bus_unregister_driver(&dell_uart_backlight_driver); > +} > + > +module_init(dell_uart_bl_init); > +module_exit(dell_uart_bl_exit); > +MODULE_DEVICE_TABLE(acpi, dell_uart_bl_ids); > +MODULE_DESCRIPTION("Dell AIO Serial Backlight module"); > +MODULE_AUTHOR("AceLan Kao <acelan.kao@canonical.com>"); > +MODULE_LICENSE("GPL"); > diff --git a/drivers/platform/x86/dell-uart-backlight.h b/drivers/platform/x86/dell-uart-backlight.h > new file mode 100644 > index 000000000000..e4fe74fae6a8 > --- /dev/null > +++ b/drivers/platform/x86/dell-uart-backlight.h > @@ -0,0 +1,36 @@ > +/* > + * Dell AIO Serial Backlight Driver > + * > + * Copyright (C) 2017 AceLan Kao <acelan.kao@canonical.com> > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + */ > + > +#ifndef _DELL_UART_BACKLIGHT_H_ > +#define _DELL_UART_BACKLIGHT_H_ > + > +enum { > + DELL_UART_GET_FIRMWARE_VER, > + DELL_UART_GET_SCALAR, > + DELL_UART_GET_BRIGHTNESS, > + DELL_UART_SET_BRIGHTNESS, > + DELL_UART_SET_BACKLIGHT_POWER, > +}; > + > +struct dell_uart_bl_cmd { > + unsigned char cmd[10]; > + unsigned char ret[80]; > + unsigned short tx_len; > + unsigned short rx_len; > +}; > + > +#endif /* _DELL_UART_BACKLIGHT_H_ */ >
Colin Ian King <colin.king@canonical.com> 於 2018年9月7日 週五 下午5:11寫道： > > On 06/09/18 09:19, AceLan Kao wrote: > > BugLink: https://bugs.launchpad.net/bugs/1727235 > > > > The Dell AIO machines released after 2017 come with a UART interface > > to communicate with the backlight scalar board. This driver creates > > a standard backlight interface and talks to the scalar board through > > UART. > > > > In DSDT this uart port will be defined as > > Name (_HID, "DELL0501") > > Name (_CID, EisaId ("PNP0501") > > The 8250 PNP driver will be loaded by default, and this driver uses > > "DELL0501" to confirm the uart port is a backlight interface and > > leverage the port created by 8250 PNP driver to communicate with > > the scalar board. > > > > v2: > > 1. move struct uart_cmd to .c file > > 2. make dell_uart_get_bl_power() inline > > 3. add space to ternary operator "bl_cmd->cmd[2] = power ? 0 : 1;" > > 4. check return value of kzalloc() > > 5. add kzfree() > > 6. check return value of backlight_device_register() > > 7. check return value of filp_open() at init > > v3: > > 1. Fix compiling warning. > > > > Signed-off-by: AceLan Kao <acelan.kao@canonical.com> > > --- > > drivers/platform/x86/Kconfig | 14 + > > drivers/platform/x86/Makefile | 1 + > > drivers/platform/x86/dell-uart-backlight.c | 463 +++++++++++++++++++++ > > drivers/platform/x86/dell-uart-backlight.h | 36 ++ > > 4 files changed, 514 insertions(+) > > create mode 100644 drivers/platform/x86/dell-uart-backlight.c > > create mode 100644 drivers/platform/x86/dell-uart-backlight.h > > > > diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig > > index b6ac37a5d06d..b6ce1a5b01e5 100644 > > --- a/drivers/platform/x86/Kconfig > > +++ b/drivers/platform/x86/Kconfig > > @@ -199,6 +199,20 @@ config DELL_RBTN > > To compile this driver as a module, choose M here: the module will > > be called dell-rbtn. > > > > +config DELL_UART_BACKLIGHT > > + tristate "Dell AIO UART Backlight driver" > > + depends on SERIAL_8250 > > + depends on ACPI > > + ---help--- > > + Say Y here if you want to support Dell AIO UART backlight interface. > > + The Dell AIO machines released after 2017 come with a UART interface > > + to communicate with the backlight scalar board. This driver creates > > + a standard backlight interface and talks to the scalar board through > > + UART to adjust the AIO screen brightness. > > + > > + To compile this driver as a module, choose M here: the module will > > + be called dell_uart_backlight. > > + > > > > config FUJITSU_LAPTOP > > tristate "Fujitsu Laptop Extras" > > diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile > > index c32b34a72467..85329fd26afd 100644 > > --- a/drivers/platform/x86/Makefile > > +++ b/drivers/platform/x86/Makefile > > @@ -22,6 +22,7 @@ obj-$(CONFIG_DELL_WMI_AIO) += dell-wmi-aio.o > > obj-$(CONFIG_DELL_WMI_LED) += dell-wmi-led.o > > obj-$(CONFIG_DELL_SMO8800) += dell-smo8800.o > > obj-$(CONFIG_DELL_RBTN) += dell-rbtn.o > > +obj-$(CONFIG_DELL_UART_BACKLIGHT) += dell-uart-backlight.o > > obj-$(CONFIG_ACER_WMI) += acer-wmi.o > > obj-$(CONFIG_ACERHDF) += acerhdf.o > > obj-$(CONFIG_HP_ACCEL) += hp_accel.o > > diff --git a/drivers/platform/x86/dell-uart-backlight.c b/drivers/platform/x86/dell-uart-backlight.c > > new file mode 100644 > > index 000000000000..eae075cfcadb > > --- /dev/null > > +++ b/drivers/platform/x86/dell-uart-backlight.c > > @@ -0,0 +1,463 @@ > > +/* > > + * Dell AIO Serial Backlight Driver > > + * > > + * Copyright (C) 2017 AceLan Kao <acelan.kao@canonical.com> > > + * > > + * This program is free software; you can redistribute it and/or modify > > + * it under the terms of the GNU General Public License as published by > > + * the Free Software Foundation; either version 2 of the License, or > > + * (at your option) any later version. > > + * > > + * This program is distributed in the hope that it will be useful, > > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > > + * GNU General Public License for more details. > > + * > > + */ > > + > > +#include <linux/kernel.h> > > +#include <linux/module.h> > > +#include <linux/acpi.h> > > +#include <linux/serial_8250.h> > > +#include <linux/delay.h> > > +#include <linux/backlight.h> > > +#include <acpi/video.h> > > + > > +#include "dell-uart-backlight.h" > > + > > +struct dell_uart_backlight { > > + struct device *dev; > > + struct backlight_device *dell_uart_bd; > > + struct mutex brightness_mutex; > > + int line; > > + int bl_power; > > +}; > > +struct uart_8250_port *serial8250_get_port(int line); > > +struct tty_struct *tty; > > +struct file *ftty; > > Should tty and ftty be static? Right, thanks. > > > + > > +unsigned int (*io_serial_in)(struct uart_port *p, int offset); > > +int (*uart_write)(struct tty_struct *tty, const unsigned char *buf, int count); > > +int (*uart_chars_in_buffer)(struct tty_struct *tty); > > + > > +static struct dell_uart_bl_cmd uart_cmd[] = { > > Would it make sense for uart_cmd to be also const? uart_cmd provides the return buffer, so it can't be const > > > + /* > > + * Get Firmware Version: Tool uses this command to get firmware version. > > + * Command: 0x6A 0x06 0x8F (Length:3 Type: 0x0A, Cmd:6 Checksum:0x8F) > > + * Return data: 0x0D 0x06 Data checksum (Length:13,Cmd:0x06, > > + * Data :F/W version(APRILIA=APR27-VXXX,PHINE=PHI23-VXXX), > > + * checksum:SUM(Length and Cmd and Data)xor 0xFF . > > + */ > > + [DELL_UART_GET_FIRMWARE_VER] = { > > + .cmd = {0x6A, 0x06, 0x8F}, > > + .tx_len = 3, > > + }, > > + /* > > + * Get Brightness level: Application uses this command for scaler to get brightness. > > + * Command: 0x6A 0x0C 0x89 (Length:3 Type: 0x0A, Cmd:0x0C, Checksum:0x89) > > + * Return data: 0x04 0x0C Data checksum > > + * (Length:4 Cmd: 0x0C Data: brightness level checksum: SUM(Length and Cmd and Data)xor 0xFF) > > + * brightness level which ranges from 0~100. > > + */ > > + [DELL_UART_GET_BRIGHTNESS] = { > > + .cmd = {0x6A, 0x0C, 0x89}, > > + .ret = {0x04, 0x0C, 0x00, 0x00}, > > + .tx_len = 3, > > + .rx_len = 4, > > + }, > > + /* Set Brightness level: Application uses this command for scaler to set brightness. > > + * Command: 0x8A 0x0B Byte2 Checksum (Length:4 Type: 0x0A, Cmd:0x0B) > > + * where Byte2 is the brightness level which ranges from 0~100. > > + * Return data: 0x03 0x0B 0xF1(Length:3,Cmd:B,checksum:0xF1) > > + * Scaler must send the 3bytes ack within 1 second when success, other value if error > > + */ > > + [DELL_UART_SET_BRIGHTNESS] = { > > + .cmd = {0x8A, 0x0B, 0x0, 0x0}, > > + .ret = {0x03, 0x0B, 0xF1}, > > + .tx_len = 4, > > + .rx_len = 3, > > + }, > > + /* > > + * Screen ON/OFF Control: Application uses this command to control screen ON or OFF. > > + * Command: 0x8A 0x0E Byte2 Checksum (Length:4 Type: 0x0A, Cmd:0x0E) where > > + * Byte2=0 to turn OFF the screen. > > + * Byte2=1 to turn ON the screen > > + * Other value of Byte2 is reserved and invalid. > > + * Return data: 0x03 0x0E 0xEE(Length:3,Cmd:E,checksum:0xEE) > > + */ > > + [DELL_UART_SET_BACKLIGHT_POWER] = { > > + .cmd = {0x8A, 0x0E, 0x00, 0x0}, > > + .ret = {0x03, 0x0E, 0xEE}, > > + .tx_len = 4, > > + .rx_len = 3, > > + }, > > +}; > > + > > +static int dell_uart_write(struct uart_8250_port *up, __u8 *buf, int len) > > +{ > > + int actual = 0; > > + struct uart_port *port = &up->port; > > + > > + tty_port_tty_wakeup(&port->state->port); > > + tty = tty_port_tty_get(&port->state->port); > > + actual = uart_write(tty, buf, len); > > + while (uart_chars_in_buffer(tty)) { > > + udelay(10); > > + } > > + > > + return actual; > > +} > > + > > +static int dell_uart_read(struct uart_8250_port *up, __u8 *buf, int len) > > +{ > > + int i, retry; > > + unsigned long flags; > > + > > + spin_lock_irqsave(&up->port.lock, flags); > > + for (i = 0; i < len; i++) { > > + retry = 10; > > + while (!(io_serial_in(&up->port, UART_LSR) & UART_LSR_DR)) { > > + if (--retry == 0) > > + break; > > + mdelay(20); > > + } > > + > > + if (retry == 0) > > + break; > > + buf[i] = io_serial_in(&up->port, UART_RX); > > + } > > + spin_unlock_irqrestore(&up->port.lock, flags); > > + > > + return i; > > +} > > + > > +static void dell_uart_dump_cmd(const char *func, const char *prefix, > > + const char *cmd, int len) > > +{ > > + char buf[80]; > > + > > + snprintf(buf, 80, "dell_uart_backlight:%s:%s", func, prefix); > > + if (len != 0) > > + print_hex_dump_debug(buf, DUMP_PREFIX_NONE, > > + 16, 1, cmd, len, false); > > + else > > + pr_debug("dell_uart_backlight:%s:%sNULL\n", func, prefix); > > + > > +} > > + > > +/* > > + * checksum: SUM(Length and Cmd and Data)xor 0xFF) > > + */ > > +static unsigned char dell_uart_checksum(unsigned char *buf, int len) > > +{ > > + unsigned char val = 0; > > + > > + while (len-- > 0) > > + val += buf[len]; > > + > > + return val ^ 0xff; > > +} > > + > > +/* > > + * There is no command to get backlight power status, > > + * so we set the backlight power to "on" while initializing, > > + * and then track and report its status by bl_power variable > > + */ > > +static int inline dell_uart_get_bl_power(struct dell_uart_backlight *dell_pdata) > > +{ > > + return dell_pdata->bl_power; > > +} > > + > > +static int dell_uart_set_bl_power(struct backlight_device *bd, int power) > > +{ > > + struct dell_uart_bl_cmd *bl_cmd = > > + &uart_cmd[DELL_UART_SET_BACKLIGHT_POWER]; > > + struct dell_uart_backlight *dell_pdata = bl_get_data(bd); > > + struct uart_8250_port *uart = serial8250_get_port(dell_pdata->line); > > + int rx_len; > > + > > + if (power != FB_BLANK_POWERDOWN) > > + power = FB_BLANK_UNBLANK; > > + > > + bl_cmd->cmd[2] = power ? 0 : 1; > > + bl_cmd->cmd[3] = dell_uart_checksum(bl_cmd->cmd, bl_cmd->tx_len - 1); > > + > > + dell_uart_dump_cmd(__func__, "tx: ", bl_cmd->cmd, bl_cmd->tx_len); > > + > > + if (mutex_lock_killable(&dell_pdata->brightness_mutex) < 0) { > > + pr_debug("Failed to get mutex_lock"); > > + return 0; > > + } > > + > > + dell_uart_write(uart, bl_cmd->cmd, bl_cmd->tx_len); > > + rx_len = dell_uart_read(uart, bl_cmd->ret, bl_cmd->rx_len); > > + > > + mutex_unlock(&dell_pdata->brightness_mutex); > > + > > + dell_uart_dump_cmd(__func__, "rx: ", bl_cmd->ret, rx_len); > > + > > + bd->props.power = power; > > + dell_pdata->bl_power = power; > > + > > + return 0; > > +} > > + > > +static int dell_uart_get_brightness(struct backlight_device *bd) > > +{ > > + struct dell_uart_bl_cmd *bl_cmd = &uart_cmd[DELL_UART_GET_BRIGHTNESS]; > > + struct dell_uart_backlight *dell_pdata = bl_get_data(bd); > > + struct uart_8250_port *uart = serial8250_get_port(dell_pdata->line); > > + int rx_len, brightness = 0; > > + > > + dell_uart_dump_cmd(__func__, "tx: ", bl_cmd->cmd, bl_cmd->tx_len); > > + > > + if (mutex_lock_killable(&dell_pdata->brightness_mutex) < 0) { > > + pr_debug("Failed to get mutex_lock"); > > + return 0; > > + } > > + > > + dell_uart_write(uart, bl_cmd->cmd, bl_cmd->tx_len); > > + rx_len = dell_uart_read(uart, bl_cmd->ret, bl_cmd->rx_len); > > + > > + mutex_unlock(&dell_pdata->brightness_mutex); > > + > > + dell_uart_dump_cmd(__func__, "rx: ", bl_cmd->ret, rx_len); > > + > > + brightness = (unsigned int)bl_cmd->ret[2]; > > + > > + return brightness; > > +} > > + > > +static int dell_uart_update_status(struct backlight_device *bd) > > +{ > > + struct dell_uart_bl_cmd *bl_cmd = &uart_cmd[DELL_UART_SET_BRIGHTNESS]; > > + struct dell_uart_backlight *dell_pdata = bl_get_data(bd); > > + struct uart_8250_port *uart = serial8250_get_port(dell_pdata->line); > > + int rx_len; > > + > > + bl_cmd->cmd[2] = bd->props.brightness; > > + bl_cmd->cmd[3] = dell_uart_checksum(bl_cmd->cmd, bl_cmd->tx_len - 1); > > + > > + dell_uart_dump_cmd(__func__, "tx: ", bl_cmd->cmd, bl_cmd->tx_len); > > + > > + if (mutex_lock_killable(&dell_pdata->brightness_mutex) < 0) { > > + pr_debug("Failed to get mutex_lock"); > > + return 0; > > + } > > + > > + dell_uart_write(uart, bl_cmd->cmd, bl_cmd->tx_len); > > + rx_len = dell_uart_read(uart, bl_cmd->ret, bl_cmd->rx_len); > > + > > + mutex_unlock(&dell_pdata->brightness_mutex); > > + > > + dell_uart_dump_cmd(__func__, "rx: ", bl_cmd->ret, rx_len); > > + > > + if (bd->props.power != dell_uart_get_bl_power(dell_pdata)) > > + dell_uart_set_bl_power(bd, bd->props.power); > > + > > + return 0; > > +} > > + > > +static int dell_uart_get_scalar_status(struct dell_uart_backlight *dell_pdata) > > +{ > > + struct dell_uart_bl_cmd *bl_cmd = &uart_cmd[DELL_UART_GET_SCALAR]; > > + struct uart_8250_port *uart = serial8250_get_port(dell_pdata->line); > > + int rx_len, status = 1; /* assume the scalar IC controls backlight if the command failed */ > > + > > + dell_uart_dump_cmd(__func__, "tx: ", bl_cmd->cmd, bl_cmd->tx_len); > > + > > + if (mutex_lock_killable(&dell_pdata->brightness_mutex) < 0) { > > + pr_debug("Failed to get mutex_lock"); > > + return 0; > > + } > > + > > + dell_uart_write(uart, bl_cmd->cmd, bl_cmd->tx_len); > > + rx_len = dell_uart_read(uart, bl_cmd->ret, bl_cmd->rx_len); > > + > > + mutex_unlock(&dell_pdata->brightness_mutex); > > + > > + dell_uart_dump_cmd(__func__, "rx: ", bl_cmd->ret, rx_len); > > + > > + if (rx_len == 4) > > + status = (unsigned int)bl_cmd->ret[2]; > > + > > + return status; > > +} > > + > > +static int dell_uart_show_firmware_ver(struct dell_uart_backlight *dell_pdata) > > +{ > > + struct dell_uart_bl_cmd *bl_cmd = &uart_cmd[DELL_UART_GET_FIRMWARE_VER]; > > + struct uart_8250_port *uart = serial8250_get_port(dell_pdata->line); > > + int rx_len = 0, retry = 10; > > + > > + dell_uart_dump_cmd(__func__, "tx: ", bl_cmd->cmd, bl_cmd->tx_len); > > + > > + if (mutex_lock_killable(&dell_pdata->brightness_mutex) < 0) { > > + pr_debug("Failed to get mutex_lock"); > > + return -1; > > + } > > + > > + dell_uart_write(uart, bl_cmd->cmd, bl_cmd->tx_len); > > + while (retry-- > 0) { > > + /* first byte is data length */ > > + dell_uart_read(uart, bl_cmd->ret, 1); > > + rx_len = (int)bl_cmd->ret[0]; > > + if (bl_cmd->ret[0] > 80 || bl_cmd->ret[0] <= 0) { > > Minor quibble, bl_cmd->ret is unsigned char, so it can never be < than > zero. Perhaps bl_cmd->ret[0] == 0 is better Fixed, thanks. > > > + pr_debug("Failed to get firmware version\n"); > > + if (retry == 0) { > > + mutex_unlock(&dell_pdata->brightness_mutex); > > + return -1; > > + } > > + msleep(100); > > + continue; > > + } > > + > > + dell_uart_read(uart, bl_cmd->ret+1, rx_len-1); > > + break; > > + } > > + mutex_unlock(&dell_pdata->brightness_mutex); > > + > > + dell_uart_dump_cmd(__func__, "rx: ", bl_cmd->ret, rx_len); > > + > > + pr_debug("Firmare str(%d)= %s\n", (int)bl_cmd->ret[0], bl_cmd->ret+2); > > + return rx_len; > > +} > > + > > +static const struct backlight_ops dell_uart_backlight_ops = { > > + .get_brightness = dell_uart_get_brightness, > > + .update_status = dell_uart_update_status, > > +}; > > + > > +static int dell_uart_startup(struct dell_uart_backlight *dell_pdata) > > +{ > > + struct uart_8250_port *uartp; > > + struct uart_port *port; > > + > > + dell_pdata->line = 0; > > + uartp = serial8250_get_port(dell_pdata->line); > > + port = &uartp->port; > > + tty = port->state->port.tty; > > + io_serial_in = port->serial_in; > > + uart_write = tty->driver->ops->write; > > + uart_chars_in_buffer = tty->driver->ops->chars_in_buffer; > > + > > + return 0; > > +} > > + > > +static int dell_uart_bl_add(struct acpi_device *dev) > > +{ > > + struct dell_uart_backlight *dell_pdata; > > + struct backlight_properties props; > > + struct backlight_device *dell_uart_bd; > > + > > + dell_pdata = kzalloc(sizeof(struct dell_uart_backlight), GFP_KERNEL); > > + if (!dell_pdata) { > > + pr_debug("Failed to allocate memory for dell_uart_backlight\n"); > > + return -1; > > + } > > + dell_pdata->dev = &dev->dev; > > + dell_uart_startup(dell_pdata); > > + dev->driver_data = dell_pdata; > > + > > + mutex_init(&dell_pdata->brightness_mutex); > > + > > + if (!dell_uart_get_scalar_status(dell_pdata)) { > > + udelay(50); > > + /* try another command to make sure there is no scalar IC */ > > + if (dell_uart_show_firmware_ver(dell_pdata) <= 0) { > > + pr_debug("Scalar is not in charge of brightness adjustment.\n"); > > + kzfree(dell_pdata); > > + return -1; > > + } > > + } > > + > > + memset(&props, 0, sizeof(struct backlight_properties)); > > + props.type = BACKLIGHT_PLATFORM; > > + props.max_brightness = 100; > > + > > + dell_uart_bd = backlight_device_register("dell_uart_backlight", > > + &dev->dev, > > + dell_pdata, > > + &dell_uart_backlight_ops, > > + &props); > > + if (IS_ERR(dell_uart_bd)) { > > + kzfree(dell_pdata); > > + pr_debug("Backlight registration failed\n"); > > + return -1; > > + } > > + > > + dell_pdata->dell_uart_bd = dell_uart_bd; > > + > > + dell_uart_set_bl_power(dell_uart_bd, FB_BLANK_UNBLANK); > > + dell_uart_bd->props.brightness = 100; > > + backlight_update_status(dell_uart_bd); > > + > > + /* unregister acpi backlight interface */ > > + acpi_video_set_dmi_backlight_type(acpi_backlight_vendor); > > + > > + return 0; > > +} > > + > > +static int dell_uart_bl_remove(struct acpi_device *dev) > > +{ > > + struct dell_uart_backlight *dell_pdata = dev->driver_data; > > + > > + backlight_device_unregister(dell_pdata->dell_uart_bd); > > + kzfree(dell_pdata); > > + > > + return 0; > > +} > > + > > +static int dell_uart_bl_suspend(struct device *dev) > > +{ > > + filp_close(ftty, NULL); > > + return 0; > > +} > > + > > +static int dell_uart_bl_resume(struct device *dev) > > +{ > > + ftty = filp_open("/dev/ttyS0", O_RDWR | O_NOCTTY | O_NDELAY, 0); > > + return 0; > > +} > > + > > +static SIMPLE_DEV_PM_OPS(dell_uart_bl_pm, dell_uart_bl_suspend, dell_uart_bl_resume); > > + > > +static const struct acpi_device_id dell_uart_bl_ids[] = { > > + {"DELL0501", 0}, > > + {"", 0}, > > +}; > > + > > +static struct acpi_driver dell_uart_backlight_driver = { > > + .name = "Dell AIO serial backlight", > > + .ids = dell_uart_bl_ids, > > + .ops = { > > + .add = dell_uart_bl_add, > > + .remove = dell_uart_bl_remove, > > + }, > > + .drv.pm = &dell_uart_bl_pm, > > +}; > > + > > +static int __init dell_uart_bl_init(void) > > +{ > > + ftty = filp_open("/dev/ttyS0", O_RDWR | O_NOCTTY | O_NDELAY, 0); > > + if (IS_ERR(ftty)) { > > + pr_debug("cannot open /dev/ttyS0\n"); > > + return -EINVAL; > > + } > > + > > + return acpi_bus_register_driver(&dell_uart_backlight_driver); > > +} > > + > > +static void __exit dell_uart_bl_exit(void) > > +{ > > + filp_close(ftty, NULL); > > + > > + acpi_bus_unregister_driver(&dell_uart_backlight_driver); > > +} > > + > > +module_init(dell_uart_bl_init); > > +module_exit(dell_uart_bl_exit); > > +MODULE_DEVICE_TABLE(acpi, dell_uart_bl_ids); > > +MODULE_DESCRIPTION("Dell AIO Serial Backlight module"); > > +MODULE_AUTHOR("AceLan Kao <acelan.kao@canonical.com>"); > > +MODULE_LICENSE("GPL"); > > diff --git a/drivers/platform/x86/dell-uart-backlight.h b/drivers/platform/x86/dell-uart-backlight.h > > new file mode 100644 > > index 000000000000..e4fe74fae6a8 > > --- /dev/null > > +++ b/drivers/platform/x86/dell-uart-backlight.h > > @@ -0,0 +1,36 @@ > > +/* > > + * Dell AIO Serial Backlight Driver > > + * > > + * Copyright (C) 2017 AceLan Kao <acelan.kao@canonical.com> > > + * > > + * This program is free software; you can redistribute it and/or modify > > + * it under the terms of the GNU General Public License as published by > > + * the Free Software Foundation; either version 2 of the License, or > > + * (at your option) any later version. > > + * > > + * This program is distributed in the hope that it will be useful, > > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > > + * GNU General Public License for more details. > > + * > > + */ > > + > > +#ifndef _DELL_UART_BACKLIGHT_H_ > > +#define _DELL_UART_BACKLIGHT_H_ > > + > > +enum { > > + DELL_UART_GET_FIRMWARE_VER, > > + DELL_UART_GET_SCALAR, > > + DELL_UART_GET_BRIGHTNESS, > > + DELL_UART_SET_BRIGHTNESS, > > + DELL_UART_SET_BACKLIGHT_POWER, > > +}; > > + > > +struct dell_uart_bl_cmd { > > + unsigned char cmd[10]; > > + unsigned char ret[80]; > > + unsigned short tx_len; > > + unsigned short rx_len; > > +}; > > + > > +#endif /* _DELL_UART_BACKLIGHT_H_ */ > > I'll submit v4 soon.
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig index b6ac37a5d06d..b6ce1a5b01e5 100644 --- a/drivers/platform/x86/Kconfig +++ b/drivers/platform/x86/Kconfig @@ -199,6 +199,20 @@ config DELL_RBTN To compile this driver as a module, choose M here: the module will be called dell-rbtn. +config DELL_UART_BACKLIGHT + tristate "Dell AIO UART Backlight driver" + depends on SERIAL_8250 + depends on ACPI + ---help--- + Say Y here if you want to support Dell AIO UART backlight interface. + The Dell AIO machines released after 2017 come with a UART interface + to communicate with the backlight scalar board. This driver creates + a standard backlight interface and talks to the scalar board through + UART to adjust the AIO screen brightness. + + To compile this driver as a module, choose M here: the module will + be called dell_uart_backlight. + config FUJITSU_LAPTOP tristate "Fujitsu Laptop Extras" diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile index c32b34a72467..85329fd26afd 100644 --- a/drivers/platform/x86/Makefile +++ b/drivers/platform/x86/Makefile @@ -22,6 +22,7 @@ obj-$(CONFIG_DELL_WMI_AIO) += dell-wmi-aio.o obj-$(CONFIG_DELL_WMI_LED) += dell-wmi-led.o obj-$(CONFIG_DELL_SMO8800) += dell-smo8800.o obj-$(CONFIG_DELL_RBTN) += dell-rbtn.o +obj-$(CONFIG_DELL_UART_BACKLIGHT) += dell-uart-backlight.o obj-$(CONFIG_ACER_WMI) += acer-wmi.o obj-$(CONFIG_ACERHDF) += acerhdf.o obj-$(CONFIG_HP_ACCEL) += hp_accel.o diff --git a/drivers/platform/x86/dell-uart-backlight.c b/drivers/platform/x86/dell-uart-backlight.c new file mode 100644 index 000000000000..eae075cfcadb --- /dev/null +++ b/drivers/platform/x86/dell-uart-backlight.c @@ -0,0 +1,463 @@ +/* + * Dell AIO Serial Backlight Driver + * + * Copyright (C) 2017 AceLan Kao <acelan.kao@canonical.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/acpi.h> +#include <linux/serial_8250.h> +#include <linux/delay.h> +#include <linux/backlight.h> +#include <acpi/video.h> + +#include "dell-uart-backlight.h" + +struct dell_uart_backlight { + struct device *dev; + struct backlight_device *dell_uart_bd; + struct mutex brightness_mutex; + int line; + int bl_power; +}; +struct uart_8250_port *serial8250_get_port(int line); +struct tty_struct *tty; +struct file *ftty; + +unsigned int (*io_serial_in)(struct uart_port *p, int offset); +int (*uart_write)(struct tty_struct *tty, const unsigned char *buf, int count); +int (*uart_chars_in_buffer)(struct tty_struct *tty); + +static struct dell_uart_bl_cmd uart_cmd[] = { + /* + * Get Firmware Version: Tool uses this command to get firmware version. + * Command: 0x6A 0x06 0x8F (Length:3 Type: 0x0A, Cmd:6 Checksum:0x8F) + * Return data: 0x0D 0x06 Data checksum (Length:13,Cmd:0x06, + * Data :F/W version(APRILIA=APR27-VXXX,PHINE=PHI23-VXXX), + * checksum:SUM(Length and Cmd and Data)xor 0xFF . + */ + [DELL_UART_GET_FIRMWARE_VER] = { + .cmd = {0x6A, 0x06, 0x8F}, + .tx_len = 3, + }, + /* + * Get Brightness level: Application uses this command for scaler to get brightness. + * Command: 0x6A 0x0C 0x89 (Length:3 Type: 0x0A, Cmd:0x0C, Checksum:0x89) + * Return data: 0x04 0x0C Data checksum + * (Length:4 Cmd: 0x0C Data: brightness level checksum: SUM(Length and Cmd and Data)xor 0xFF) + * brightness level which ranges from 0~100. + */ + [DELL_UART_GET_BRIGHTNESS] = { + .cmd = {0x6A, 0x0C, 0x89}, + .ret = {0x04, 0x0C, 0x00, 0x00}, + .tx_len = 3, + .rx_len = 4, + }, + /* Set Brightness level: Application uses this command for scaler to set brightness. + * Command: 0x8A 0x0B Byte2 Checksum (Length:4 Type: 0x0A, Cmd:0x0B) + * where Byte2 is the brightness level which ranges from 0~100. + * Return data: 0x03 0x0B 0xF1(Length:3,Cmd:B,checksum:0xF1) + * Scaler must send the 3bytes ack within 1 second when success, other value if error + */ + [DELL_UART_SET_BRIGHTNESS] = { + .cmd = {0x8A, 0x0B, 0x0, 0x0}, + .ret = {0x03, 0x0B, 0xF1}, + .tx_len = 4, + .rx_len = 3, + }, + /* + * Screen ON/OFF Control: Application uses this command to control screen ON or OFF. + * Command: 0x8A 0x0E Byte2 Checksum (Length:4 Type: 0x0A, Cmd:0x0E) where + * Byte2=0 to turn OFF the screen. + * Byte2=1 to turn ON the screen + * Other value of Byte2 is reserved and invalid. + * Return data: 0x03 0x0E 0xEE(Length:3,Cmd:E,checksum:0xEE) + */ + [DELL_UART_SET_BACKLIGHT_POWER] = { + .cmd = {0x8A, 0x0E, 0x00, 0x0}, + .ret = {0x03, 0x0E, 0xEE}, + .tx_len = 4, + .rx_len = 3, + }, +}; + +static int dell_uart_write(struct uart_8250_port *up, __u8 *buf, int len) +{ + int actual = 0; + struct uart_port *port = &up->port; + + tty_port_tty_wakeup(&port->state->port); + tty = tty_port_tty_get(&port->state->port); + actual = uart_write(tty, buf, len); + while (uart_chars_in_buffer(tty)) { + udelay(10); + } + + return actual; +} + +static int dell_uart_read(struct uart_8250_port *up, __u8 *buf, int len) +{ + int i, retry; + unsigned long flags; + + spin_lock_irqsave(&up->port.lock, flags); + for (i = 0; i < len; i++) { + retry = 10; + while (!(io_serial_in(&up->port, UART_LSR) & UART_LSR_DR)) { + if (--retry == 0) + break; + mdelay(20); + } + + if (retry == 0) + break; + buf[i] = io_serial_in(&up->port, UART_RX); + } + spin_unlock_irqrestore(&up->port.lock, flags); + + return i; +} + +static void dell_uart_dump_cmd(const char *func, const char *prefix, + const char *cmd, int len) +{ + char buf[80]; + + snprintf(buf, 80, "dell_uart_backlight:%s:%s", func, prefix); + if (len != 0) + print_hex_dump_debug(buf, DUMP_PREFIX_NONE, + 16, 1, cmd, len, false); + else + pr_debug("dell_uart_backlight:%s:%sNULL\n", func, prefix); + +} + +/* + * checksum: SUM(Length and Cmd and Data)xor 0xFF) + */ +static unsigned char dell_uart_checksum(unsigned char *buf, int len) +{ + unsigned char val = 0; + + while (len-- > 0) + val += buf[len]; + + return val ^ 0xff; +} + +/* + * There is no command to get backlight power status, + * so we set the backlight power to "on" while initializing, + * and then track and report its status by bl_power variable + */ +static int inline dell_uart_get_bl_power(struct dell_uart_backlight *dell_pdata) +{ + return dell_pdata->bl_power; +} + +static int dell_uart_set_bl_power(struct backlight_device *bd, int power) +{ + struct dell_uart_bl_cmd *bl_cmd = + &uart_cmd[DELL_UART_SET_BACKLIGHT_POWER]; + struct dell_uart_backlight *dell_pdata = bl_get_data(bd); + struct uart_8250_port *uart = serial8250_get_port(dell_pdata->line); + int rx_len; + + if (power != FB_BLANK_POWERDOWN) + power = FB_BLANK_UNBLANK; + + bl_cmd->cmd[2] = power ? 0 : 1; + bl_cmd->cmd[3] = dell_uart_checksum(bl_cmd->cmd, bl_cmd->tx_len - 1); + + dell_uart_dump_cmd(__func__, "tx: ", bl_cmd->cmd, bl_cmd->tx_len); + + if (mutex_lock_killable(&dell_pdata->brightness_mutex) < 0) { + pr_debug("Failed to get mutex_lock"); + return 0; + } + + dell_uart_write(uart, bl_cmd->cmd, bl_cmd->tx_len); + rx_len = dell_uart_read(uart, bl_cmd->ret, bl_cmd->rx_len); + + mutex_unlock(&dell_pdata->brightness_mutex); + + dell_uart_dump_cmd(__func__, "rx: ", bl_cmd->ret, rx_len); + + bd->props.power = power; + dell_pdata->bl_power = power; + + return 0; +} + +static int dell_uart_get_brightness(struct backlight_device *bd) +{ + struct dell_uart_bl_cmd *bl_cmd = &uart_cmd[DELL_UART_GET_BRIGHTNESS]; + struct dell_uart_backlight *dell_pdata = bl_get_data(bd); + struct uart_8250_port *uart = serial8250_get_port(dell_pdata->line); + int rx_len, brightness = 0; + + dell_uart_dump_cmd(__func__, "tx: ", bl_cmd->cmd, bl_cmd->tx_len); + + if (mutex_lock_killable(&dell_pdata->brightness_mutex) < 0) { + pr_debug("Failed to get mutex_lock"); + return 0; + } + + dell_uart_write(uart, bl_cmd->cmd, bl_cmd->tx_len); + rx_len = dell_uart_read(uart, bl_cmd->ret, bl_cmd->rx_len); + + mutex_unlock(&dell_pdata->brightness_mutex); + + dell_uart_dump_cmd(__func__, "rx: ", bl_cmd->ret, rx_len); + + brightness = (unsigned int)bl_cmd->ret[2]; + + return brightness; +} + +static int dell_uart_update_status(struct backlight_device *bd) +{ + struct dell_uart_bl_cmd *bl_cmd = &uart_cmd[DELL_UART_SET_BRIGHTNESS]; + struct dell_uart_backlight *dell_pdata = bl_get_data(bd); + struct uart_8250_port *uart = serial8250_get_port(dell_pdata->line); + int rx_len; + + bl_cmd->cmd[2] = bd->props.brightness; + bl_cmd->cmd[3] = dell_uart_checksum(bl_cmd->cmd, bl_cmd->tx_len - 1); + + dell_uart_dump_cmd(__func__, "tx: ", bl_cmd->cmd, bl_cmd->tx_len); + + if (mutex_lock_killable(&dell_pdata->brightness_mutex) < 0) { + pr_debug("Failed to get mutex_lock"); + return 0; + } + + dell_uart_write(uart, bl_cmd->cmd, bl_cmd->tx_len); + rx_len = dell_uart_read(uart, bl_cmd->ret, bl_cmd->rx_len); + + mutex_unlock(&dell_pdata->brightness_mutex); + + dell_uart_dump_cmd(__func__, "rx: ", bl_cmd->ret, rx_len); + + if (bd->props.power != dell_uart_get_bl_power(dell_pdata)) + dell_uart_set_bl_power(bd, bd->props.power); + + return 0; +} + +static int dell_uart_get_scalar_status(struct dell_uart_backlight *dell_pdata) +{ + struct dell_uart_bl_cmd *bl_cmd = &uart_cmd[DELL_UART_GET_SCALAR]; + struct uart_8250_port *uart = serial8250_get_port(dell_pdata->line); + int rx_len, status = 1; /* assume the scalar IC controls backlight if the command failed */ + + dell_uart_dump_cmd(__func__, "tx: ", bl_cmd->cmd, bl_cmd->tx_len); + + if (mutex_lock_killable(&dell_pdata->brightness_mutex) < 0) { + pr_debug("Failed to get mutex_lock"); + return 0; + } + + dell_uart_write(uart, bl_cmd->cmd, bl_cmd->tx_len); + rx_len = dell_uart_read(uart, bl_cmd->ret, bl_cmd->rx_len); + + mutex_unlock(&dell_pdata->brightness_mutex); + + dell_uart_dump_cmd(__func__, "rx: ", bl_cmd->ret, rx_len); + + if (rx_len == 4) + status = (unsigned int)bl_cmd->ret[2]; + + return status; +} + +static int dell_uart_show_firmware_ver(struct dell_uart_backlight *dell_pdata) +{ + struct dell_uart_bl_cmd *bl_cmd = &uart_cmd[DELL_UART_GET_FIRMWARE_VER]; + struct uart_8250_port *uart = serial8250_get_port(dell_pdata->line); + int rx_len = 0, retry = 10; + + dell_uart_dump_cmd(__func__, "tx: ", bl_cmd->cmd, bl_cmd->tx_len); + + if (mutex_lock_killable(&dell_pdata->brightness_mutex) < 0) { + pr_debug("Failed to get mutex_lock"); + return -1; + } + + dell_uart_write(uart, bl_cmd->cmd, bl_cmd->tx_len); + while (retry-- > 0) { + /* first byte is data length */ + dell_uart_read(uart, bl_cmd->ret, 1); + rx_len = (int)bl_cmd->ret[0]; + if (bl_cmd->ret[0] > 80 || bl_cmd->ret[0] <= 0) { + pr_debug("Failed to get firmware version\n"); + if (retry == 0) { + mutex_unlock(&dell_pdata->brightness_mutex); + return -1; + } + msleep(100); + continue; + } + + dell_uart_read(uart, bl_cmd->ret+1, rx_len-1); + break; + } + mutex_unlock(&dell_pdata->brightness_mutex); + + dell_uart_dump_cmd(__func__, "rx: ", bl_cmd->ret, rx_len); + + pr_debug("Firmare str(%d)= %s\n", (int)bl_cmd->ret[0], bl_cmd->ret+2); + return rx_len; +} + +static const struct backlight_ops dell_uart_backlight_ops = { + .get_brightness = dell_uart_get_brightness, + .update_status = dell_uart_update_status, +}; + +static int dell_uart_startup(struct dell_uart_backlight *dell_pdata) +{ + struct uart_8250_port *uartp; + struct uart_port *port; + + dell_pdata->line = 0; + uartp = serial8250_get_port(dell_pdata->line); + port = &uartp->port; + tty = port->state->port.tty; + io_serial_in = port->serial_in; + uart_write = tty->driver->ops->write; + uart_chars_in_buffer = tty->driver->ops->chars_in_buffer; + + return 0; +} + +static int dell_uart_bl_add(struct acpi_device *dev) +{ + struct dell_uart_backlight *dell_pdata; + struct backlight_properties props; + struct backlight_device *dell_uart_bd; + + dell_pdata = kzalloc(sizeof(struct dell_uart_backlight), GFP_KERNEL); + if (!dell_pdata) { + pr_debug("Failed to allocate memory for dell_uart_backlight\n"); + return -1; + } + dell_pdata->dev = &dev->dev; + dell_uart_startup(dell_pdata); + dev->driver_data = dell_pdata; + + mutex_init(&dell_pdata->brightness_mutex); + + if (!dell_uart_get_scalar_status(dell_pdata)) { + udelay(50); + /* try another command to make sure there is no scalar IC */ + if (dell_uart_show_firmware_ver(dell_pdata) <= 0) { + pr_debug("Scalar is not in charge of brightness adjustment.\n"); + kzfree(dell_pdata); + return -1; + } + } + + memset(&props, 0, sizeof(struct backlight_properties)); + props.type = BACKLIGHT_PLATFORM; + props.max_brightness = 100; + + dell_uart_bd = backlight_device_register("dell_uart_backlight", + &dev->dev, + dell_pdata, + &dell_uart_backlight_ops, + &props); + if (IS_ERR(dell_uart_bd)) { + kzfree(dell_pdata); + pr_debug("Backlight registration failed\n"); + return -1; + } + + dell_pdata->dell_uart_bd = dell_uart_bd; + + dell_uart_set_bl_power(dell_uart_bd, FB_BLANK_UNBLANK); + dell_uart_bd->props.brightness = 100; + backlight_update_status(dell_uart_bd); + + /* unregister acpi backlight interface */ + acpi_video_set_dmi_backlight_type(acpi_backlight_vendor); + + return 0; +} + +static int dell_uart_bl_remove(struct acpi_device *dev) +{ + struct dell_uart_backlight *dell_pdata = dev->driver_data; + + backlight_device_unregister(dell_pdata->dell_uart_bd); + kzfree(dell_pdata); + + return 0; +} + +static int dell_uart_bl_suspend(struct device *dev) +{ + filp_close(ftty, NULL); + return 0; +} + +static int dell_uart_bl_resume(struct device *dev) +{ + ftty = filp_open("/dev/ttyS0", O_RDWR | O_NOCTTY | O_NDELAY, 0); + return 0; +} + +static SIMPLE_DEV_PM_OPS(dell_uart_bl_pm, dell_uart_bl_suspend, dell_uart_bl_resume); + +static const struct acpi_device_id dell_uart_bl_ids[] = { + {"DELL0501", 0}, + {"", 0}, +}; + +static struct acpi_driver dell_uart_backlight_driver = { + .name = "Dell AIO serial backlight", + .ids = dell_uart_bl_ids, + .ops = { + .add = dell_uart_bl_add, + .remove = dell_uart_bl_remove, + }, + .drv.pm = &dell_uart_bl_pm, +}; + +static int __init dell_uart_bl_init(void) +{ + ftty = filp_open("/dev/ttyS0", O_RDWR | O_NOCTTY | O_NDELAY, 0); + if (IS_ERR(ftty)) { + pr_debug("cannot open /dev/ttyS0\n"); + return -EINVAL; + } + + return acpi_bus_register_driver(&dell_uart_backlight_driver); +} + +static void __exit dell_uart_bl_exit(void) +{ + filp_close(ftty, NULL); + + acpi_bus_unregister_driver(&dell_uart_backlight_driver); +} + +module_init(dell_uart_bl_init); +module_exit(dell_uart_bl_exit); +MODULE_DEVICE_TABLE(acpi, dell_uart_bl_ids); +MODULE_DESCRIPTION("Dell AIO Serial Backlight module"); +MODULE_AUTHOR("AceLan Kao <acelan.kao@canonical.com>"); +MODULE_LICENSE("GPL"); diff --git a/drivers/platform/x86/dell-uart-backlight.h b/drivers/platform/x86/dell-uart-backlight.h new file mode 100644 index 000000000000..e4fe74fae6a8 --- /dev/null +++ b/drivers/platform/x86/dell-uart-backlight.h @@ -0,0 +1,36 @@ +/* + * Dell AIO Serial Backlight Driver + * + * Copyright (C) 2017 AceLan Kao <acelan.kao@canonical.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#ifndef _DELL_UART_BACKLIGHT_H_ +#define _DELL_UART_BACKLIGHT_H_ + +enum { + DELL_UART_GET_FIRMWARE_VER, + DELL_UART_GET_SCALAR, + DELL_UART_GET_BRIGHTNESS, + DELL_UART_SET_BRIGHTNESS, + DELL_UART_SET_BACKLIGHT_POWER, +}; + +struct dell_uart_bl_cmd { + unsigned char cmd[10]; + unsigned char ret[80]; + unsigned short tx_len; + unsigned short rx_len; +}; + +#endif /* _DELL_UART_BACKLIGHT_H_ */
BugLink: https://bugs.launchpad.net/bugs/1727235 The Dell AIO machines released after 2017 come with a UART interface to communicate with the backlight scalar board. This driver creates a standard backlight interface and talks to the scalar board through UART. In DSDT this uart port will be defined as Name (_HID, "DELL0501") Name (_CID, EisaId ("PNP0501") The 8250 PNP driver will be loaded by default, and this driver uses "DELL0501" to confirm the uart port is a backlight interface and leverage the port created by 8250 PNP driver to communicate with the scalar board. v2: 1. move struct uart_cmd to .c file 2. make dell_uart_get_bl_power() inline 3. add space to ternary operator "bl_cmd->cmd[2] = power ? 0 : 1;" 4. check return value of kzalloc() 5. add kzfree() 6. check return value of backlight_device_register() 7. check return value of filp_open() at init v3: 1. Fix compiling warning. Signed-off-by: AceLan Kao <acelan.kao@canonical.com> --- drivers/platform/x86/Kconfig | 14 + drivers/platform/x86/Makefile | 1 + drivers/platform/x86/dell-uart-backlight.c | 463 +++++++++++++++++++++ drivers/platform/x86/dell-uart-backlight.h | 36 ++ 4 files changed, 514 insertions(+) create mode 100644 drivers/platform/x86/dell-uart-backlight.c create mode 100644 drivers/platform/x86/dell-uart-backlight.h