| Message ID | 1420706857-6257-4-git-send-email-yamada.m@jp.panasonic.com |
|---|---|
| State | Superseded |
| Delegated to: | Masahiro Yamada |
| Headers | show |
Hi Masahiro, On 8 January 2015 at 00:47, Masahiro Yamada <yamada.m@jp.panasonic.com> wrote: > This commit adds on-chip I2C driver used on newer SoCs of Panasonic > UniPhier platform. > > Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com> > Reviewed-by: Simon Glass <sjg@chromium.org> > Acked-by: Heiko Schocher <hs@denx.de> Acked-by: Simon Glass <sjg@chromium.org> A few nits below. If you prefer with the last two I can fix them when applying. The first one you probably don't want to change. > --- > > Changes in v5: > - Drop unnecessary __packed > > Changes in v4: > - Use a structure instead of macros for register access > > Changes in v3: > - Fix a bug in that device busy is checked even if the stop > condition is not issued. > > Changes in v2: > - Fix a typo. s/freqency/frequency/ > - Rename the struct member for clarification. s/wait_us/timeout/ > - Add comments on all the registers > - Skip stop condition if the next message is read > > drivers/i2c/Kconfig | 8 + > drivers/i2c/Makefile | 1 + > drivers/i2c/i2c-uniphier-f.c | 380 +++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 389 insertions(+) > create mode 100644 drivers/i2c/i2c-uniphier-f.c > > diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig > index 6a479ef..202ea5d 100644 > --- a/drivers/i2c/Kconfig > +++ b/drivers/i2c/Kconfig > @@ -12,3 +12,11 @@ config SYS_I2C_UNIPHIER > help > Support for Panasonic UniPhier I2C controller driver. This I2C > controller is used on PH1-LD4, PH1-sLD8 or older UniPhier SoCs. > + > +config SYS_I2C_UNIPHIER_F > + bool "UniPhier FIFO-builtin I2C driver" > + depends on ARCH_UNIPHIER && DM_I2C > + default y > + help > + Support for Panasonic UniPhier FIFO-builtin I2C controller driver. > + This I2C controller is used on PH1-Pro4 or newer UniPhier SoCs. > diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile > index e2fcd24..0e4c9f4 100644 > --- a/drivers/i2c/Makefile > +++ b/drivers/i2c/Makefile > @@ -32,4 +32,5 @@ obj-$(CONFIG_SYS_I2C_SH) += sh_i2c.o > obj-$(CONFIG_SYS_I2C_SOFT) += soft_i2c.o > obj-$(CONFIG_SYS_I2C_TEGRA) += tegra_i2c.o > obj-$(CONFIG_SYS_I2C_UNIPHIER) += i2c-uniphier.o > +obj-$(CONFIG_SYS_I2C_UNIPHIER_F) += i2c-uniphier-f.o > obj-$(CONFIG_SYS_I2C_ZYNQ) += zynq_i2c.o > diff --git a/drivers/i2c/i2c-uniphier-f.c b/drivers/i2c/i2c-uniphier-f.c > new file mode 100644 > index 0000000..7bd524c > --- /dev/null > +++ b/drivers/i2c/i2c-uniphier-f.c > @@ -0,0 +1,380 @@ > +/* > + * Copyright (C) 2014 Panasonic Corporation > + * Author: Masahiro Yamada <yamada.m@jp.panasonic.com> > + * > + * SPDX-License-Identifier: GPL-2.0+ > + */ > + > +#include <common.h> > +#include <linux/types.h> > +#include <asm/io.h> > +#include <asm/errno.h> > +#include <dm/device.h> > +#include <dm/root.h> > +#include <i2c.h> > +#include <fdtdec.h> > + > +DECLARE_GLOBAL_DATA_PTR; > + > +struct uniphier_fi2c_regs { > + u32 cr; /* control register */ > +#define I2C_CR_MST (1 << 3) /* master mode */ > +#define I2C_CR_STA (1 << 2) /* start condition */ > +#define I2C_CR_STO (1 << 1) /* stop condition */ > +#define I2C_CR_NACK (1 << 0) /* not ACK */ > + u32 dttx; /* send FIFO (write-only) */ > +#define dtrx dttx /* receive FIFO (read-only) */ > +#define I2C_DTTX_CMD (1 << 8) /* send command (slave addr) */ > +#define I2C_DTTX_RD (1 << 0) /* read */ > + u32 __reserved; /* no register at offset 0x08 */ > + u32 slad; /* slave address */ > + u32 cyc; /* clock cycle control */ > + u32 lctl; /* clock low period control */ > + u32 ssut; /* restart/stop setup time control */ > + u32 dsut; /* data setup time control */ > + u32 intr; /* interrupt status */ > + u32 ie; /* interrupt enable */ > + u32 ic; /* interrupt clear */ > +#define I2C_INT_TE (1 << 9) /* TX FIFO empty */ > +#define I2C_INT_RB (1 << 4) /* received specified bytes */ > +#define I2C_INT_NA (1 << 2) /* no answer */ > +#define I2C_INT_AL (1 << 1) /* arbitration lost */ > + u32 sr; /* status register */ > +#define I2C_SR_DB (1 << 12) /* device busy */ > +#define I2C_SR_BB (1 << 8) /* bus busy */ > +#define I2C_SR_RFF (1 << 3) /* Rx FIFO full */ > +#define I2C_SR_RNE (1 << 2) /* Rx FIFO not empty */ > +#define I2C_SR_TNF (1 << 1) /* Tx FIFO not full */ > +#define I2C_SR_TFE (1 << 0) /* Tx FIFO empty */ > + u32 __reserved2; /* no register at offset 0x30 */ > + u32 rst; /* reset control */ > +#define I2C_RST_TBRST (1 << 2) /* clear Tx FIFO */ > +#define I2C_RST_RBRST (1 << 1) /* clear Rx FIFO */ > +#define I2C_RST_RST (1 << 0) /* forcible bus reset */ > + u32 bm; /* bus monitor */ > + u32 noise; /* noise filter control */ > + u32 tbc; /* Tx byte count setting */ > + u32 rbc; /* Rx byte count setting */ > + u32 tbcm; /* Tx byte count monitor */ > + u32 rbcm; /* Rx byte count monitor */ > + u32 brst; /* bus reset */ > +#define I2C_BRST_FOEN (1 << 1) /* normal operation */ > +#define I2C_BRST_RSCLO (1 << 0) /* release SCL low fixing */ > +}; > + > +#define FIOCLK 50000000 > + > +struct uniphier_fi2c_dev { > + struct uniphier_fi2c_regs __iomem *regs; /* register base */ > + unsigned long fioclk; /* internal operation clock */ > + unsigned long timeout; /* time out (us) */ > +}; > + > +static int poll_status(u32 __iomem *reg, u32 flag) > +{ > + int wait = 1000000; /* 1 sec */ > + > + while (readl(reg) & flag) { > + if (wait-- < 0) > + return -EREMOTEIO; > + udelay(1); > + } > + > + return 0; > +} > + > +static int reset_bus(struct uniphier_fi2c_dev *dev) Optional - you could pass struct uniphier_fi2c_regs to this function and the next. > +{ > + int ret; > + > + /* bus forcible reset */ > + writel(I2C_RST_RST, &dev->regs->rst); > + ret = poll_status(&dev->regs->rst, I2C_RST_RST); > + if (ret < 0) > + debug("error: fail to reset I2C controller\n"); > + > + return ret; > +} > + > +static int check_device_busy(struct uniphier_fi2c_dev *dev) > +{ > + int ret; > + > + ret = poll_status(&dev->regs->sr, I2C_SR_DB); > + if (ret < 0) { > + debug("error: device busy too long. reset...\n"); > + ret = reset_bus(dev); > + } > + > + return ret; > +} > + > +static int uniphier_fi2c_probe(struct udevice *dev) > +{ > + fdt_addr_t addr; > + fdt_size_t size; > + struct uniphier_fi2c_dev *priv = dev_get_priv(dev); > + int ret; > + > + addr = fdtdec_get_addr_size(gd->fdt_blob, dev->of_offset, "reg", > + &size); > + > + priv->regs = map_sysmem(addr, size); > + > + if (!priv->regs) > + return -ENOMEM; > + > + priv->fioclk = FIOCLK; > + > + /* bus forcible reset */ > + ret = reset_bus(priv); > + if (ret < 0) > + return ret; > + > + writel(I2C_BRST_FOEN | I2C_BRST_RSCLO, &priv->regs->brst); > + > + return 0; > +} > + > +static int uniphier_fi2c_remove(struct udevice *dev) > +{ > + struct uniphier_fi2c_dev *priv = dev_get_priv(dev); > + > + unmap_sysmem(priv->regs); > + > + return 0; > +} > + > +static int uniphier_fi2c_child_pre_probe(struct udevice *dev) > +{ > + struct dm_i2c_chip *i2c_chip = dev_get_parentdata(dev); > + > + if (dev->of_offset == -1) > + return 0; > + return i2c_chip_ofdata_to_platdata(gd->fdt_blob, dev->of_offset, > + i2c_chip); > +} > + > +static int wait_for_irq(struct uniphier_fi2c_dev *dev, u32 flags, > + bool *stop) > +{ > + u32 irq; > + unsigned long wait = dev->timeout; > + int ret = -EREMOTEIO; > + > + do { > + udelay(1); > + irq = readl(&dev->regs->intr); > + } while (!(irq & flags) && wait--); > + > + if (wait < 0) { > + debug("error: time out\n"); > + return ret; > + } > + > + if (irq & I2C_INT_AL) { > + debug("error: arbitration lost\n"); > + *stop = false; > + return ret; > + } > + > + if (irq & I2C_INT_NA) { > + debug("error: no answer\n"); > + return ret; > + } > + > + return 0; > +} > + > +int issue_stop(struct uniphier_fi2c_dev *dev, int old_ret) static? > +{ > + int ret; > + > + debug("stop condition\n"); > + writel(I2C_CR_MST | I2C_CR_STO, &dev->regs->cr); > + > + ret = poll_status(&dev->regs->sr, I2C_SR_DB); > + if (ret < 0) > + debug("error: device busy after operation\n"); > + > + return old_ret ? old_ret : ret; > +} > + > +static int uniphier_fi2c_transmit(struct uniphier_fi2c_dev *dev, uint addr, > + uint len, const u8 *buf, bool *stop) > +{ > + int ret; > + const u32 irq_flags = I2C_INT_TE | I2C_INT_NA | I2C_INT_AL; > + struct uniphier_fi2c_regs __iomem *regs = dev->regs; > + > + debug("%s: addr = %x, len = %d\n", __func__, addr, len); > + > + writel(I2C_DTTX_CMD | addr << 1, ®s->dttx); > + > + writel(irq_flags, ®s->ie); > + writel(irq_flags, ®s->ic); > + > + debug("start condition\n"); > + writel(I2C_CR_MST | I2C_CR_STA, ®s->cr); > + > + ret = wait_for_irq(dev, irq_flags, stop); > + if (ret < 0) > + goto error; > + > + while (len--) { > + debug("sending %x\n", *buf); > + writel(*buf++, ®s->dttx); > + > + writel(irq_flags, ®s->ic); > + > + ret = wait_for_irq(dev, irq_flags, stop); > + if (ret < 0) > + goto error; > + } > + > +error: > + writel(irq_flags, ®s->ic); > + > + if (*stop) > + ret = issue_stop(dev, ret); > + > + return ret; > +} > + > +static int uniphier_fi2c_receive(struct uniphier_fi2c_dev *dev, uint addr, > + uint len, u8 *buf, bool *stop) > +{ > + int ret = 0; > + const u32 irq_flags = I2C_INT_RB | I2C_INT_NA | I2C_INT_AL; > + struct uniphier_fi2c_regs __iomem *regs = dev->regs; > + > + debug("%s: addr = %x, len = %d\n", __func__, addr, len); > + > + /* > + * In case 'len == 0', only the slave address should be sent > + * for probing, which is covered by the transmit function. > + */ > + if (len == 0) > + return uniphier_fi2c_transmit(dev, addr, len, buf, stop); > + > + writel(I2C_DTTX_CMD | I2C_DTTX_RD | addr << 1, ®s->dttx); > + > + writel(0, ®s->rbc); > + writel(irq_flags, ®s->ie); > + writel(irq_flags, ®s->ic); > + > + debug("start condition\n"); > + writel(I2C_CR_MST | I2C_CR_STA | (len == 1 ? I2C_CR_NACK : 0), > + ®s->cr); > + > + while (len--) { > + ret = wait_for_irq(dev, irq_flags, stop); > + if (ret < 0) > + goto error; > + > + *buf++ = readl(®s->dtrx); > + debug("received %x\n", *(buf - 1)); > + > + if (len == 1) > + writel(I2C_CR_MST | I2C_CR_NACK, ®s->cr); > + > + writel(irq_flags, ®s->ic); > + } > + > +error: > + writel(irq_flags, ®s->ic); > + > + if (*stop) > + ret = issue_stop(dev, ret); > + > + return ret; > +} > + > +static int uniphier_fi2c_xfer(struct udevice *bus, struct i2c_msg *msg, > + int nmsgs) > +{ > + int ret; > + struct uniphier_fi2c_dev *dev = dev_get_priv(bus); > + bool stop; > + extra blank line > + > + ret = check_device_busy(dev); > + if (ret < 0) > + return ret; > + > + for (; nmsgs > 0; nmsgs--, msg++) { > + /* If next message is read, skip the stop condition */ > + stop = nmsgs > 1 && msg[1].flags & I2C_M_RD ? false : true; > + > + if (msg->flags & I2C_M_RD) > + ret = uniphier_fi2c_receive(dev, msg->addr, msg->len, > + msg->buf, &stop); > + else > + ret = uniphier_fi2c_transmit(dev, msg->addr, msg->len, > + msg->buf, &stop); > + > + if (ret < 0) > + break; > + } > + > + return ret; > +} > + > +static int uniphier_fi2c_set_bus_speed(struct udevice *bus, unsigned int speed) > +{ > + int ret; > + unsigned int clk_count; > + struct uniphier_fi2c_dev *dev = dev_get_priv(bus); > + struct uniphier_fi2c_regs __iomem *regs = dev->regs; > + > + /* max supported frequency is 400 kHz */ > + if (speed > 400000) > + return -EINVAL; > + > + ret = check_device_busy(dev); > + if (ret < 0) > + return ret; > + > + /* make sure the bus is idle when changing the frequency */ > + writel(I2C_BRST_RSCLO, ®s->brst); > + > + clk_count = dev->fioclk / speed; > + > + writel(clk_count, ®s->cyc); > + writel(clk_count / 2, ®s->lctl); > + writel(clk_count / 2, ®s->ssut); > + writel(clk_count / 16, ®s->dsut); > + > + writel(I2C_BRST_FOEN | I2C_BRST_RSCLO, ®s->brst); > + > + /* > + * Theoretically, each byte can be transferred in > + * 1000000 * 9 / speed usec. > + * This time out value is long enough. > + */ > + dev->timeout = 100000000L / speed; > + > + return 0; > +} > + > +static const struct dm_i2c_ops uniphier_fi2c_ops = { > + .xfer = uniphier_fi2c_xfer, > + .set_bus_speed = uniphier_fi2c_set_bus_speed, > +}; > + > +static const struct udevice_id uniphier_fi2c_of_match[] = { > + { .compatible = "panasonic,uniphier-fi2c" }, > + {}, > +}; > + > +U_BOOT_DRIVER(uniphier_fi2c) = { > + .name = "uniphier-fi2c", > + .id = UCLASS_I2C, > + .of_match = uniphier_fi2c_of_match, > + .probe = uniphier_fi2c_probe, > + .remove = uniphier_fi2c_remove, > + .per_child_auto_alloc_size = sizeof(struct dm_i2c_chip), > + .child_pre_probe = uniphier_fi2c_child_pre_probe, > + .priv_auto_alloc_size = sizeof(struct uniphier_fi2c_dev), > + .ops = &uniphier_fi2c_ops, > +}; Regards, Simon
Hi Simon, On Mon, 12 Jan 2015 17:42:52 -0800 Simon Glass <sjg@chromium.org> wrote: > Hi Masahiro, > > On 8 January 2015 at 00:47, Masahiro Yamada <yamada.m@jp.panasonic.com> wrote: > > This commit adds on-chip I2C driver used on newer SoCs of Panasonic > > UniPhier platform. > > > > Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com> > > Reviewed-by: Simon Glass <sjg@chromium.org> > > Acked-by: Heiko Schocher <hs@denx.de> > > Acked-by: Simon Glass <sjg@chromium.org> > > A few nits below. If you prefer with the last two I can fix them when > applying. The first one you probably don't want to change. Thanks for your close review! All of the three look nice, but I do not generally like local re-work. I have sent v6 that is deregated to you. When you find some time, please get it in via u-boot-dm. And can you please apply this too? http://patchwork.ozlabs.org/patch/415596/ Best Regards Masahiro Yamada
diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig index 6a479ef..202ea5d 100644 --- a/drivers/i2c/Kconfig +++ b/drivers/i2c/Kconfig @@ -12,3 +12,11 @@ config SYS_I2C_UNIPHIER help Support for Panasonic UniPhier I2C controller driver. This I2C controller is used on PH1-LD4, PH1-sLD8 or older UniPhier SoCs. + +config SYS_I2C_UNIPHIER_F + bool "UniPhier FIFO-builtin I2C driver" + depends on ARCH_UNIPHIER && DM_I2C + default y + help + Support for Panasonic UniPhier FIFO-builtin I2C controller driver. + This I2C controller is used on PH1-Pro4 or newer UniPhier SoCs. diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile index e2fcd24..0e4c9f4 100644 --- a/drivers/i2c/Makefile +++ b/drivers/i2c/Makefile @@ -32,4 +32,5 @@ obj-$(CONFIG_SYS_I2C_SH) += sh_i2c.o obj-$(CONFIG_SYS_I2C_SOFT) += soft_i2c.o obj-$(CONFIG_SYS_I2C_TEGRA) += tegra_i2c.o obj-$(CONFIG_SYS_I2C_UNIPHIER) += i2c-uniphier.o +obj-$(CONFIG_SYS_I2C_UNIPHIER_F) += i2c-uniphier-f.o obj-$(CONFIG_SYS_I2C_ZYNQ) += zynq_i2c.o diff --git a/drivers/i2c/i2c-uniphier-f.c b/drivers/i2c/i2c-uniphier-f.c new file mode 100644 index 0000000..7bd524c --- /dev/null +++ b/drivers/i2c/i2c-uniphier-f.c @@ -0,0 +1,380 @@ +/* + * Copyright (C) 2014 Panasonic Corporation + * Author: Masahiro Yamada <yamada.m@jp.panasonic.com> + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <linux/types.h> +#include <asm/io.h> +#include <asm/errno.h> +#include <dm/device.h> +#include <dm/root.h> +#include <i2c.h> +#include <fdtdec.h> + +DECLARE_GLOBAL_DATA_PTR; + +struct uniphier_fi2c_regs { + u32 cr; /* control register */ +#define I2C_CR_MST (1 << 3) /* master mode */ +#define I2C_CR_STA (1 << 2) /* start condition */ +#define I2C_CR_STO (1 << 1) /* stop condition */ +#define I2C_CR_NACK (1 << 0) /* not ACK */ + u32 dttx; /* send FIFO (write-only) */ +#define dtrx dttx /* receive FIFO (read-only) */ +#define I2C_DTTX_CMD (1 << 8) /* send command (slave addr) */ +#define I2C_DTTX_RD (1 << 0) /* read */ + u32 __reserved; /* no register at offset 0x08 */ + u32 slad; /* slave address */ + u32 cyc; /* clock cycle control */ + u32 lctl; /* clock low period control */ + u32 ssut; /* restart/stop setup time control */ + u32 dsut; /* data setup time control */ + u32 intr; /* interrupt status */ + u32 ie; /* interrupt enable */ + u32 ic; /* interrupt clear */ +#define I2C_INT_TE (1 << 9) /* TX FIFO empty */ +#define I2C_INT_RB (1 << 4) /* received specified bytes */ +#define I2C_INT_NA (1 << 2) /* no answer */ +#define I2C_INT_AL (1 << 1) /* arbitration lost */ + u32 sr; /* status register */ +#define I2C_SR_DB (1 << 12) /* device busy */ +#define I2C_SR_BB (1 << 8) /* bus busy */ +#define I2C_SR_RFF (1 << 3) /* Rx FIFO full */ +#define I2C_SR_RNE (1 << 2) /* Rx FIFO not empty */ +#define I2C_SR_TNF (1 << 1) /* Tx FIFO not full */ +#define I2C_SR_TFE (1 << 0) /* Tx FIFO empty */ + u32 __reserved2; /* no register at offset 0x30 */ + u32 rst; /* reset control */ +#define I2C_RST_TBRST (1 << 2) /* clear Tx FIFO */ +#define I2C_RST_RBRST (1 << 1) /* clear Rx FIFO */ +#define I2C_RST_RST (1 << 0) /* forcible bus reset */ + u32 bm; /* bus monitor */ + u32 noise; /* noise filter control */ + u32 tbc; /* Tx byte count setting */ + u32 rbc; /* Rx byte count setting */ + u32 tbcm; /* Tx byte count monitor */ + u32 rbcm; /* Rx byte count monitor */ + u32 brst; /* bus reset */ +#define I2C_BRST_FOEN (1 << 1) /* normal operation */ +#define I2C_BRST_RSCLO (1 << 0) /* release SCL low fixing */ +}; + +#define FIOCLK 50000000 + +struct uniphier_fi2c_dev { + struct uniphier_fi2c_regs __iomem *regs; /* register base */ + unsigned long fioclk; /* internal operation clock */ + unsigned long timeout; /* time out (us) */ +}; + +static int poll_status(u32 __iomem *reg, u32 flag) +{ + int wait = 1000000; /* 1 sec */ + + while (readl(reg) & flag) { + if (wait-- < 0) + return -EREMOTEIO; + udelay(1); + } + + return 0; +} + +static int reset_bus(struct uniphier_fi2c_dev *dev) +{ + int ret; + + /* bus forcible reset */ + writel(I2C_RST_RST, &dev->regs->rst); + ret = poll_status(&dev->regs->rst, I2C_RST_RST); + if (ret < 0) + debug("error: fail to reset I2C controller\n"); + + return ret; +} + +static int check_device_busy(struct uniphier_fi2c_dev *dev) +{ + int ret; + + ret = poll_status(&dev->regs->sr, I2C_SR_DB); + if (ret < 0) { + debug("error: device busy too long. reset...\n"); + ret = reset_bus(dev); + } + + return ret; +} + +static int uniphier_fi2c_probe(struct udevice *dev) +{ + fdt_addr_t addr; + fdt_size_t size; + struct uniphier_fi2c_dev *priv = dev_get_priv(dev); + int ret; + + addr = fdtdec_get_addr_size(gd->fdt_blob, dev->of_offset, "reg", + &size); + + priv->regs = map_sysmem(addr, size); + + if (!priv->regs) + return -ENOMEM; + + priv->fioclk = FIOCLK; + + /* bus forcible reset */ + ret = reset_bus(priv); + if (ret < 0) + return ret; + + writel(I2C_BRST_FOEN | I2C_BRST_RSCLO, &priv->regs->brst); + + return 0; +} + +static int uniphier_fi2c_remove(struct udevice *dev) +{ + struct uniphier_fi2c_dev *priv = dev_get_priv(dev); + + unmap_sysmem(priv->regs); + + return 0; +} + +static int uniphier_fi2c_child_pre_probe(struct udevice *dev) +{ + struct dm_i2c_chip *i2c_chip = dev_get_parentdata(dev); + + if (dev->of_offset == -1) + return 0; + return i2c_chip_ofdata_to_platdata(gd->fdt_blob, dev->of_offset, + i2c_chip); +} + +static int wait_for_irq(struct uniphier_fi2c_dev *dev, u32 flags, + bool *stop) +{ + u32 irq; + unsigned long wait = dev->timeout; + int ret = -EREMOTEIO; + + do { + udelay(1); + irq = readl(&dev->regs->intr); + } while (!(irq & flags) && wait--); + + if (wait < 0) { + debug("error: time out\n"); + return ret; + } + + if (irq & I2C_INT_AL) { + debug("error: arbitration lost\n"); + *stop = false; + return ret; + } + + if (irq & I2C_INT_NA) { + debug("error: no answer\n"); + return ret; + } + + return 0; +} + +int issue_stop(struct uniphier_fi2c_dev *dev, int old_ret) +{ + int ret; + + debug("stop condition\n"); + writel(I2C_CR_MST | I2C_CR_STO, &dev->regs->cr); + + ret = poll_status(&dev->regs->sr, I2C_SR_DB); + if (ret < 0) + debug("error: device busy after operation\n"); + + return old_ret ? old_ret : ret; +} + +static int uniphier_fi2c_transmit(struct uniphier_fi2c_dev *dev, uint addr, + uint len, const u8 *buf, bool *stop) +{ + int ret; + const u32 irq_flags = I2C_INT_TE | I2C_INT_NA | I2C_INT_AL; + struct uniphier_fi2c_regs __iomem *regs = dev->regs; + + debug("%s: addr = %x, len = %d\n", __func__, addr, len); + + writel(I2C_DTTX_CMD | addr << 1, ®s->dttx); + + writel(irq_flags, ®s->ie); + writel(irq_flags, ®s->ic); + + debug("start condition\n"); + writel(I2C_CR_MST | I2C_CR_STA, ®s->cr); + + ret = wait_for_irq(dev, irq_flags, stop); + if (ret < 0) + goto error; + + while (len--) { + debug("sending %x\n", *buf); + writel(*buf++, ®s->dttx); + + writel(irq_flags, ®s->ic); + + ret = wait_for_irq(dev, irq_flags, stop); + if (ret < 0) + goto error; + } + +error: + writel(irq_flags, ®s->ic); + + if (*stop) + ret = issue_stop(dev, ret); + + return ret; +} + +static int uniphier_fi2c_receive(struct uniphier_fi2c_dev *dev, uint addr, + uint len, u8 *buf, bool *stop) +{ + int ret = 0; + const u32 irq_flags = I2C_INT_RB | I2C_INT_NA | I2C_INT_AL; + struct uniphier_fi2c_regs __iomem *regs = dev->regs; + + debug("%s: addr = %x, len = %d\n", __func__, addr, len); + + /* + * In case 'len == 0', only the slave address should be sent + * for probing, which is covered by the transmit function. + */ + if (len == 0) + return uniphier_fi2c_transmit(dev, addr, len, buf, stop); + + writel(I2C_DTTX_CMD | I2C_DTTX_RD | addr << 1, ®s->dttx); + + writel(0, ®s->rbc); + writel(irq_flags, ®s->ie); + writel(irq_flags, ®s->ic); + + debug("start condition\n"); + writel(I2C_CR_MST | I2C_CR_STA | (len == 1 ? I2C_CR_NACK : 0), + ®s->cr); + + while (len--) { + ret = wait_for_irq(dev, irq_flags, stop); + if (ret < 0) + goto error; + + *buf++ = readl(®s->dtrx); + debug("received %x\n", *(buf - 1)); + + if (len == 1) + writel(I2C_CR_MST | I2C_CR_NACK, ®s->cr); + + writel(irq_flags, ®s->ic); + } + +error: + writel(irq_flags, ®s->ic); + + if (*stop) + ret = issue_stop(dev, ret); + + return ret; +} + +static int uniphier_fi2c_xfer(struct udevice *bus, struct i2c_msg *msg, + int nmsgs) +{ + int ret; + struct uniphier_fi2c_dev *dev = dev_get_priv(bus); + bool stop; + + + ret = check_device_busy(dev); + if (ret < 0) + return ret; + + for (; nmsgs > 0; nmsgs--, msg++) { + /* If next message is read, skip the stop condition */ + stop = nmsgs > 1 && msg[1].flags & I2C_M_RD ? false : true; + + if (msg->flags & I2C_M_RD) + ret = uniphier_fi2c_receive(dev, msg->addr, msg->len, + msg->buf, &stop); + else + ret = uniphier_fi2c_transmit(dev, msg->addr, msg->len, + msg->buf, &stop); + + if (ret < 0) + break; + } + + return ret; +} + +static int uniphier_fi2c_set_bus_speed(struct udevice *bus, unsigned int speed) +{ + int ret; + unsigned int clk_count; + struct uniphier_fi2c_dev *dev = dev_get_priv(bus); + struct uniphier_fi2c_regs __iomem *regs = dev->regs; + + /* max supported frequency is 400 kHz */ + if (speed > 400000) + return -EINVAL; + + ret = check_device_busy(dev); + if (ret < 0) + return ret; + + /* make sure the bus is idle when changing the frequency */ + writel(I2C_BRST_RSCLO, ®s->brst); + + clk_count = dev->fioclk / speed; + + writel(clk_count, ®s->cyc); + writel(clk_count / 2, ®s->lctl); + writel(clk_count / 2, ®s->ssut); + writel(clk_count / 16, ®s->dsut); + + writel(I2C_BRST_FOEN | I2C_BRST_RSCLO, ®s->brst); + + /* + * Theoretically, each byte can be transferred in + * 1000000 * 9 / speed usec. + * This time out value is long enough. + */ + dev->timeout = 100000000L / speed; + + return 0; +} + +static const struct dm_i2c_ops uniphier_fi2c_ops = { + .xfer = uniphier_fi2c_xfer, + .set_bus_speed = uniphier_fi2c_set_bus_speed, +}; + +static const struct udevice_id uniphier_fi2c_of_match[] = { + { .compatible = "panasonic,uniphier-fi2c" }, + {}, +}; + +U_BOOT_DRIVER(uniphier_fi2c) = { + .name = "uniphier-fi2c", + .id = UCLASS_I2C, + .of_match = uniphier_fi2c_of_match, + .probe = uniphier_fi2c_probe, + .remove = uniphier_fi2c_remove, + .per_child_auto_alloc_size = sizeof(struct dm_i2c_chip), + .child_pre_probe = uniphier_fi2c_child_pre_probe, + .priv_auto_alloc_size = sizeof(struct uniphier_fi2c_dev), + .ops = &uniphier_fi2c_ops, +};