Any comments on this patch? On Mon, Nov 11, 2013 at 4:50 PM, Yuvaraj Kumar C D <yuvaraj.cd@xxxxxxxxx> wrote: > From: Vasanth Ananthan <vasanthananthan@xxxxxxxxx> > > This patch adds polling mode support for i2c-s3c2410 driver.The > SATA PHY controller's CMU and TRSV block's are of I2C register > map in exynos5250.These blocks can be configured using i2c. > > But i2c controller instance on which these block's sits lacks an > interrupt line.Also the current i2c-s3c2410 driver is only interrupt > driven, thus a polling mode support is required in the driver for > supporting this controller. This patch adds this support to the driver. > > Changes from V1: > 1.Changed the is_ack() to have even period b/w polls and > used usleep_range() instead of udelay(). > > Signed-off-by: Vasanth Ananthan <vasanth.a@xxxxxxxxxxx> > Signed-off-by: Yuvaraj Kumar C D <yuvaraj.cd@xxxxxxxxxxx> > --- > .../devicetree/bindings/i2c/i2c-s3c2410.txt | 2 + > drivers/i2c/busses/i2c-s3c2410.c | 66 +++++++++++++++++--- > 2 files changed, 58 insertions(+), 10 deletions(-) > > diff --git a/Documentation/devicetree/bindings/i2c/i2c-s3c2410.txt b/Documentation/devicetree/bindings/i2c/i2c-s3c2410.txt > index 296eb45..278de8e 100644 > --- a/Documentation/devicetree/bindings/i2c/i2c-s3c2410.txt > +++ b/Documentation/devicetree/bindings/i2c/i2c-s3c2410.txt > @@ -10,6 +10,8 @@ Required properties: > inside HDMIPHY block found on several samsung SoCs > (d) "samsung, exynos5440-i2c", for s3c2440-like i2c used > on EXYNOS5440 which does not need GPIO configuration. > + (e) "samsung, exynos5-sata-phy-i2c", for s3c2440-like i2c used as > + a host to SATA PHY controller on an internal bus. > - reg: physical base address of the controller and length of memory mapped > region. > - interrupts: interrupt number to the cpu. > diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c > index 3747b9b..08ed126 100644 > --- a/drivers/i2c/busses/i2c-s3c2410.c > +++ b/drivers/i2c/busses/i2c-s3c2410.c > @@ -85,6 +85,7 @@ > #define QUIRK_S3C2440 (1 << 0) > #define QUIRK_HDMIPHY (1 << 1) > #define QUIRK_NO_GPIO (1 << 2) > +#define QUIRK_POLL (1 << 3) > > /* Max time to wait for bus to become idle after a xfer (in us) */ > #define S3C2410_IDLE_TIMEOUT 5000 > @@ -141,6 +142,8 @@ static struct platform_device_id s3c24xx_driver_ids[] = { > }; > MODULE_DEVICE_TABLE(platform, s3c24xx_driver_ids); > > +static int i2c_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat); > + > #ifdef CONFIG_OF > static const struct of_device_id s3c24xx_i2c_match[] = { > { .compatible = "samsung,s3c2410-i2c", .data = (void *)0 }, > @@ -149,6 +152,8 @@ static const struct of_device_id s3c24xx_i2c_match[] = { > .data = (void *)(QUIRK_S3C2440 | QUIRK_HDMIPHY | QUIRK_NO_GPIO) }, > { .compatible = "samsung,exynos5440-i2c", > .data = (void *)(QUIRK_S3C2440 | QUIRK_NO_GPIO) }, > + { .compatible = "samsung,exynos5-sata-phy-i2c", > + .data = (void *)(QUIRK_S3C2440 | QUIRK_POLL | QUIRK_NO_GPIO) }, > {}, > }; > MODULE_DEVICE_TABLE(of, s3c24xx_i2c_match); > @@ -187,7 +192,8 @@ static inline void s3c24xx_i2c_master_complete(struct s3c24xx_i2c *i2c, int ret) > if (ret) > i2c->msg_idx = ret; > > - wake_up(&i2c->wait); > + if (!(i2c->quirks & QUIRK_POLL)) > + wake_up(&i2c->wait); > } > > static inline void s3c24xx_i2c_disable_ack(struct s3c24xx_i2c *i2c) > @@ -224,6 +230,22 @@ static inline void s3c24xx_i2c_enable_irq(struct s3c24xx_i2c *i2c) > writel(tmp | S3C2410_IICCON_IRQEN, i2c->regs + S3C2410_IICCON); > } > > +static bool is_ack(struct s3c24xx_i2c *i2c) > +{ > + int tries; > + > + for (tries = 50; tries; --tries) { > + if (readl(i2c->regs + S3C2410_IICCON) > + & S3C2410_IICCON_IRQPEND) { > + if (!(readl(i2c->regs + S3C2410_IICSTAT) > + & S3C2410_IICSTAT_LASTBIT)) > + return true; > + } > + usleep_range(1000, 2000); > + } > + dev_err(i2c->dev, "ack was not recieved\n"); > + return false; > +} > > /* s3c24xx_i2c_message_start > * > @@ -268,6 +290,16 @@ static void s3c24xx_i2c_message_start(struct s3c24xx_i2c *i2c, > > stat |= S3C2410_IICSTAT_START; > writel(stat, i2c->regs + S3C2410_IICSTAT); > + > + if (i2c->quirks & QUIRK_POLL) { > + while ((i2c->msg_num != 0) && is_ack(i2c)) { > + i2c_s3c_irq_nextbyte(i2c, stat); > + stat = readl(i2c->regs + S3C2410_IICSTAT); > + > + if (stat & S3C2410_IICSTAT_ARBITR) > + dev_err(i2c->dev, "deal with arbitration loss\n"); > + } > + } > } > > static inline void s3c24xx_i2c_stop(struct s3c24xx_i2c *i2c, int ret) > @@ -675,6 +707,15 @@ static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c, > s3c24xx_i2c_enable_irq(i2c); > s3c24xx_i2c_message_start(i2c, msgs); > > + if (i2c->quirks & QUIRK_POLL) { > + ret = i2c->msg_idx; > + > + if (ret != num) > + dev_dbg(i2c->dev, "incomplete xfer (%d)\n", ret); > + > + goto out; > + } > + > timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5); > > ret = i2c->msg_idx; > @@ -820,6 +861,9 @@ static int s3c24xx_i2c_clockrate(struct s3c24xx_i2c *i2c, unsigned int *got) > if (div1 == 512) > iiccon |= S3C2410_IICCON_TXDIV_512; > > + if (i2c->quirks & QUIRK_POLL) > + iiccon |= S3C2410_IICCON_SCALE(2); > + > writel(iiccon, i2c->regs + S3C2410_IICCON); > > if (i2c->quirks & QUIRK_S3C2440) { > @@ -1117,18 +1161,20 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev) > * ensure no current IRQs pending > */ > > - i2c->irq = ret = platform_get_irq(pdev, 0); > - if (ret <= 0) { > - dev_err(&pdev->dev, "cannot find IRQ\n"); > - return ret; > - } > + if (!(i2c->quirks & QUIRK_POLL)) { > + i2c->irq = ret = platform_get_irq(pdev, 0); > + if (ret <= 0) { > + dev_err(&pdev->dev, "cannot find IRQ\n"); > + return ret; > + } > > ret = devm_request_irq(&pdev->dev, i2c->irq, s3c24xx_i2c_irq, 0, > - dev_name(&pdev->dev), i2c); > + dev_name(&pdev->dev), i2c); > > - if (ret != 0) { > - dev_err(&pdev->dev, "cannot claim IRQ %d\n", i2c->irq); > - return ret; > + if (ret != 0) { > + dev_err(&pdev->dev, "cannot claim IRQ %d\n", i2c->irq); > + return ret; > + } > } > > ret = s3c24xx_i2c_register_cpufreq(i2c); > -- > 1.7.9.5 > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html