Message ID | 20200709134829.216393-1-mans0n@gorani.run |
---|---|
State | New |
Headers | show |
Series | [v6,1/2] gpio: add GPO driver for PCA9570 | expand |
On Thu, Jul 9, 2020 at 4:48 PM Sungbo Eo <mans0n@gorani.run> wrote: > > NXP PCA9570 is a 4-bit I2C GPO expander without interrupt functionality. > Its ports are controlled only by a data byte without register address. > LGTM, thanks! Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> > Datasheet: https://www.nxp.com/docs/en/data-sheet/PCA9570.pdf > Signed-off-by: Sungbo Eo <mans0n@gorani.run> > --- > v6: > * removed client > * re-added mutex > * removed template_chip > > v5: > * amended the commit message > * removed unnecessary castings > * added data to of_match_table > > v4: > * removed ->direction_input() and ->direction_output() > (Seems unnecessary to me) > * removed ->set_multiple() > (I'm not sure this implementation is really correct) > * added ->get() > (DS says we can read the status from the device) > * read current status during probe > > v3: > * remove mutex > * rename buffer to out > * simplify return statements > * replace ->probe() to ->probe_new() > * move ngpio to driver_data > (PCA9571 is 8-bit so I thought making ngpio configurable is a good idea) > > v2: > * move the direction functions below the set functions > * use devm_gpiochip_add_data() and remove the remove callback > > v1: > Tested in kernel 5.4 on an ipq40xx platform. > > This is my first time submitting a whole driver patch, and I'm not really > familiar with this PCA expander series. > Please let me know how I can improve this patch further. > > FYI there's an unmerged patch for this chip. > http://driverdev.linuxdriverproject.org/pipermail/driverdev-devel/2017-May/105602.html > I don't have PCA9571 either so I didn't add support for it. > --- > drivers/gpio/Kconfig | 8 ++ > drivers/gpio/Makefile | 1 + > drivers/gpio/gpio-pca9570.c | 146 ++++++++++++++++++++++++++++++++++++ > 3 files changed, 155 insertions(+) > create mode 100644 drivers/gpio/gpio-pca9570.c > > diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig > index c6b5c65c8405..d10dcb81b841 100644 > --- a/drivers/gpio/Kconfig > +++ b/drivers/gpio/Kconfig > @@ -962,6 +962,14 @@ config GPIO_PCA953X_IRQ > Say yes here to enable the pca953x to be used as an interrupt > controller. It requires the driver to be built in the kernel. > > +config GPIO_PCA9570 > + tristate "PCA9570 4-Bit I2C GPO expander" > + help > + Say yes here to enable the GPO driver for the NXP PCA9570 chip. > + > + To compile this driver as a module, choose M here: the module will > + be called gpio-pca9570. > + > config GPIO_PCF857X > tristate "PCF857x, PCA{85,96}7x, and MAX732[89] I2C GPIO expanders" > select GPIOLIB_IRQCHIP > diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile > index 1e4894e0bf0f..33cb40c28a61 100644 > --- a/drivers/gpio/Makefile > +++ b/drivers/gpio/Makefile > @@ -110,6 +110,7 @@ obj-$(CONFIG_GPIO_OCTEON) += gpio-octeon.o > obj-$(CONFIG_GPIO_OMAP) += gpio-omap.o > obj-$(CONFIG_GPIO_PALMAS) += gpio-palmas.o > obj-$(CONFIG_GPIO_PCA953X) += gpio-pca953x.o > +obj-$(CONFIG_GPIO_PCA9570) += gpio-pca9570.o > obj-$(CONFIG_GPIO_PCF857X) += gpio-pcf857x.o > obj-$(CONFIG_GPIO_PCH) += gpio-pch.o > obj-$(CONFIG_GPIO_PCIE_IDIO_24) += gpio-pcie-idio-24.o > diff --git a/drivers/gpio/gpio-pca9570.c b/drivers/gpio/gpio-pca9570.c > new file mode 100644 > index 000000000000..cb2b2f735c15 > --- /dev/null > +++ b/drivers/gpio/gpio-pca9570.c > @@ -0,0 +1,146 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Driver for PCA9570 I2C GPO expander > + * > + * Copyright (C) 2020 Sungbo Eo <mans0n@gorani.run> > + * > + * Based on gpio-tpic2810.c > + * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/ > + * Andrew F. Davis <afd@ti.com> > + */ > + > +#include <linux/gpio/driver.h> > +#include <linux/i2c.h> > +#include <linux/module.h> > +#include <linux/mutex.h> > +#include <linux/property.h> > + > +/** > + * struct pca9570 - GPIO driver data > + * @chip: GPIO controller chip > + * @lock: Protects write sequences > + * @out: Buffer for device register > + */ > +struct pca9570 { > + struct gpio_chip chip; > + struct mutex lock; > + u8 out; > +}; > + > +static int pca9570_read(struct pca9570 *gpio, u8 *value) > +{ > + struct i2c_client *client = to_i2c_client(gpio->chip.parent); > + int ret; > + > + ret = i2c_smbus_read_byte(client); > + if (ret < 0) > + return ret; > + > + *value = ret; > + return 0; > +} > + > +static int pca9570_write(struct pca9570 *gpio, u8 value) > +{ > + struct i2c_client *client = to_i2c_client(gpio->chip.parent); > + > + return i2c_smbus_write_byte(client, value); > +} > + > +static int pca9570_get_direction(struct gpio_chip *chip, > + unsigned offset) > +{ > + /* This device always output */ > + return GPIO_LINE_DIRECTION_OUT; > +} > + > +static int pca9570_get(struct gpio_chip *chip, unsigned offset) > +{ > + struct pca9570 *gpio = gpiochip_get_data(chip); > + u8 buffer; > + int ret; > + > + ret = pca9570_read(gpio, &buffer); > + if (ret) > + return ret; > + > + return !!(buffer & BIT(offset)); > +} > + > +static void pca9570_set(struct gpio_chip *chip, unsigned offset, int value) > +{ > + struct pca9570 *gpio = gpiochip_get_data(chip); > + u8 buffer; > + int ret; > + > + mutex_lock(&gpio->lock); > + > + buffer = gpio->out; > + if (value) > + buffer |= BIT(offset); > + else > + buffer &= ~BIT(offset); > + > + ret = pca9570_write(gpio, buffer); > + if (ret) > + goto out; > + > + gpio->out = buffer; > + > +out: > + mutex_unlock(&gpio->lock); > +} > + > +static int pca9570_probe(struct i2c_client *client) > +{ > + struct pca9570 *gpio; > + > + gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL); > + if (!gpio) > + return -ENOMEM; > + > + gpio->chip.label = client->name; > + gpio->chip.parent = &client->dev; > + gpio->chip.owner = THIS_MODULE; > + gpio->chip.get_direction = pca9570_get_direction; > + gpio->chip.get = pca9570_get; > + gpio->chip.set = pca9570_set; > + gpio->chip.base = -1; > + gpio->chip.ngpio = (uintptr_t)device_get_match_data(&client->dev); > + gpio->chip.can_sleep = true; > + > + mutex_init(&gpio->lock); > + > + /* Read the current output level */ > + pca9570_read(gpio, &gpio->out); > + > + i2c_set_clientdata(client, gpio); > + > + return devm_gpiochip_add_data(&client->dev, &gpio->chip, gpio); > +} > + > +static const struct i2c_device_id pca9570_id_table[] = { > + { "pca9570", 4 }, > + { /* sentinel */ } > +}; > +MODULE_DEVICE_TABLE(i2c, pca9570_id_table); > + > +static const struct of_device_id pca9570_of_match_table[] = { > + { .compatible = "nxp,pca9570", .data = (void *)4 }, > + { /* sentinel */ } > +}; > +MODULE_DEVICE_TABLE(of, pca9570_of_match_table); > + > +static struct i2c_driver pca9570_driver = { > + .driver = { > + .name = "pca9570", > + .of_match_table = pca9570_of_match_table, > + }, > + .probe_new = pca9570_probe, > + .id_table = pca9570_id_table, > +}; > +module_i2c_driver(pca9570_driver); > + > +MODULE_AUTHOR("Sungbo Eo <mans0n@gorani.run>"); > +MODULE_DESCRIPTION("GPIO expander driver for PCA9570"); > +MODULE_LICENSE("GPL v2"); > -- > 2.27.0 >
On Thu, Jul 9, 2020 at 3:48 PM Sungbo Eo <mans0n@gorani.run> wrote: > NXP PCA9570 is a 4-bit I2C GPO expander without interrupt functionality. > Its ports are controlled only by a data byte without register address. > > Datasheet: https://www.nxp.com/docs/en/data-sheet/PCA9570.pdf > Signed-off-by: Sungbo Eo <mans0n@gorani.run> > --- > v6: > * removed client > * re-added mutex > * removed template_chip This v6 version applied, thanks to everyone who helped out reviewing this driver!! Yours, Linus Walleij
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index c6b5c65c8405..d10dcb81b841 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -962,6 +962,14 @@ config GPIO_PCA953X_IRQ Say yes here to enable the pca953x to be used as an interrupt controller. It requires the driver to be built in the kernel. +config GPIO_PCA9570 + tristate "PCA9570 4-Bit I2C GPO expander" + help + Say yes here to enable the GPO driver for the NXP PCA9570 chip. + + To compile this driver as a module, choose M here: the module will + be called gpio-pca9570. + config GPIO_PCF857X tristate "PCF857x, PCA{85,96}7x, and MAX732[89] I2C GPIO expanders" select GPIOLIB_IRQCHIP diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 1e4894e0bf0f..33cb40c28a61 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -110,6 +110,7 @@ obj-$(CONFIG_GPIO_OCTEON) += gpio-octeon.o obj-$(CONFIG_GPIO_OMAP) += gpio-omap.o obj-$(CONFIG_GPIO_PALMAS) += gpio-palmas.o obj-$(CONFIG_GPIO_PCA953X) += gpio-pca953x.o +obj-$(CONFIG_GPIO_PCA9570) += gpio-pca9570.o obj-$(CONFIG_GPIO_PCF857X) += gpio-pcf857x.o obj-$(CONFIG_GPIO_PCH) += gpio-pch.o obj-$(CONFIG_GPIO_PCIE_IDIO_24) += gpio-pcie-idio-24.o diff --git a/drivers/gpio/gpio-pca9570.c b/drivers/gpio/gpio-pca9570.c new file mode 100644 index 000000000000..cb2b2f735c15 --- /dev/null +++ b/drivers/gpio/gpio-pca9570.c @@ -0,0 +1,146 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Driver for PCA9570 I2C GPO expander + * + * Copyright (C) 2020 Sungbo Eo <mans0n@gorani.run> + * + * Based on gpio-tpic2810.c + * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/ + * Andrew F. Davis <afd@ti.com> + */ + +#include <linux/gpio/driver.h> +#include <linux/i2c.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/property.h> + +/** + * struct pca9570 - GPIO driver data + * @chip: GPIO controller chip + * @lock: Protects write sequences + * @out: Buffer for device register + */ +struct pca9570 { + struct gpio_chip chip; + struct mutex lock; + u8 out; +}; + +static int pca9570_read(struct pca9570 *gpio, u8 *value) +{ + struct i2c_client *client = to_i2c_client(gpio->chip.parent); + int ret; + + ret = i2c_smbus_read_byte(client); + if (ret < 0) + return ret; + + *value = ret; + return 0; +} + +static int pca9570_write(struct pca9570 *gpio, u8 value) +{ + struct i2c_client *client = to_i2c_client(gpio->chip.parent); + + return i2c_smbus_write_byte(client, value); +} + +static int pca9570_get_direction(struct gpio_chip *chip, + unsigned offset) +{ + /* This device always output */ + return GPIO_LINE_DIRECTION_OUT; +} + +static int pca9570_get(struct gpio_chip *chip, unsigned offset) +{ + struct pca9570 *gpio = gpiochip_get_data(chip); + u8 buffer; + int ret; + + ret = pca9570_read(gpio, &buffer); + if (ret) + return ret; + + return !!(buffer & BIT(offset)); +} + +static void pca9570_set(struct gpio_chip *chip, unsigned offset, int value) +{ + struct pca9570 *gpio = gpiochip_get_data(chip); + u8 buffer; + int ret; + + mutex_lock(&gpio->lock); + + buffer = gpio->out; + if (value) + buffer |= BIT(offset); + else + buffer &= ~BIT(offset); + + ret = pca9570_write(gpio, buffer); + if (ret) + goto out; + + gpio->out = buffer; + +out: + mutex_unlock(&gpio->lock); +} + +static int pca9570_probe(struct i2c_client *client) +{ + struct pca9570 *gpio; + + gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL); + if (!gpio) + return -ENOMEM; + + gpio->chip.label = client->name; + gpio->chip.parent = &client->dev; + gpio->chip.owner = THIS_MODULE; + gpio->chip.get_direction = pca9570_get_direction; + gpio->chip.get = pca9570_get; + gpio->chip.set = pca9570_set; + gpio->chip.base = -1; + gpio->chip.ngpio = (uintptr_t)device_get_match_data(&client->dev); + gpio->chip.can_sleep = true; + + mutex_init(&gpio->lock); + + /* Read the current output level */ + pca9570_read(gpio, &gpio->out); + + i2c_set_clientdata(client, gpio); + + return devm_gpiochip_add_data(&client->dev, &gpio->chip, gpio); +} + +static const struct i2c_device_id pca9570_id_table[] = { + { "pca9570", 4 }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(i2c, pca9570_id_table); + +static const struct of_device_id pca9570_of_match_table[] = { + { .compatible = "nxp,pca9570", .data = (void *)4 }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, pca9570_of_match_table); + +static struct i2c_driver pca9570_driver = { + .driver = { + .name = "pca9570", + .of_match_table = pca9570_of_match_table, + }, + .probe_new = pca9570_probe, + .id_table = pca9570_id_table, +}; +module_i2c_driver(pca9570_driver); + +MODULE_AUTHOR("Sungbo Eo <mans0n@gorani.run>"); +MODULE_DESCRIPTION("GPIO expander driver for PCA9570"); +MODULE_LICENSE("GPL v2");
NXP PCA9570 is a 4-bit I2C GPO expander without interrupt functionality. Its ports are controlled only by a data byte without register address. Datasheet: https://www.nxp.com/docs/en/data-sheet/PCA9570.pdf Signed-off-by: Sungbo Eo <mans0n@gorani.run> --- v6: * removed client * re-added mutex * removed template_chip v5: * amended the commit message * removed unnecessary castings * added data to of_match_table v4: * removed ->direction_input() and ->direction_output() (Seems unnecessary to me) * removed ->set_multiple() (I'm not sure this implementation is really correct) * added ->get() (DS says we can read the status from the device) * read current status during probe v3: * remove mutex * rename buffer to out * simplify return statements * replace ->probe() to ->probe_new() * move ngpio to driver_data (PCA9571 is 8-bit so I thought making ngpio configurable is a good idea) v2: * move the direction functions below the set functions * use devm_gpiochip_add_data() and remove the remove callback v1: Tested in kernel 5.4 on an ipq40xx platform. This is my first time submitting a whole driver patch, and I'm not really familiar with this PCA expander series. Please let me know how I can improve this patch further. FYI there's an unmerged patch for this chip. http://driverdev.linuxdriverproject.org/pipermail/driverdev-devel/2017-May/105602.html I don't have PCA9571 either so I didn't add support for it. --- drivers/gpio/Kconfig | 8 ++ drivers/gpio/Makefile | 1 + drivers/gpio/gpio-pca9570.c | 146 ++++++++++++++++++++++++++++++++++++ 3 files changed, 155 insertions(+) create mode 100644 drivers/gpio/gpio-pca9570.c