Re: [U-Boot] [PATCH 16/16] i2c: uniphier-f: use readl_poll_timeout() to poll registers

Hello Masahiro,

Am 27.01.2017 um 22:53 schrieb Masahiro Yamada:

The readl_poll_timeout() is a useful helper to poll registers and error out if the condition is not met.

Signed-off-by: Masahiro Yamada yamada.masahiro@socionext.com

drivers/i2c/i2c-uniphier-f.c | 34 ++++++++++------------------------ 1 file changed, 10 insertions(+), 24 deletions(-)

Reviewed-by: Heiko Schocher hs@denx.de

bye, Heiko

diff --git a/drivers/i2c/i2c-uniphier-f.c b/drivers/i2c/i2c-uniphier-f.c index e212c13..9f0df59 100644 --- a/drivers/i2c/i2c-uniphier-f.c +++ b/drivers/i2c/i2c-uniphier-f.c @@ -9,6 +9,7 @@ #include <common.h> #include <linux/types.h> #include <linux/io.h> +#include <linux/iopoll.h> #include <linux/sizes.h> #include <linux/errno.h> #include <dm/device.h> @@ -69,26 +70,14 @@ struct uniphier_fi2c_dev { unsigned long timeout; /* time out (us) */ };

-static int poll_status(u32 __iomem *reg, u32 flag) -{

• int wait = 1000000; /* 1 sec is long enough */
• while (readl(reg) & flag) {

• if (wait-- < 0)
  

• 	return -EREMOTEIO;
  

• udelay(1);
  

• }
• return 0;

-}

• static int reset_bus(struct uniphier_fi2c_regs __iomem *regs) {

• u32 val; int ret;

  /* bus forcible reset */ writel(I2C_RST_RST, &regs->rst);

• ret = poll_status(&regs->rst, I2C_RST_RST);

• ret = readl_poll_timeout(&regs->rst, val, !(val & I2C_RST_RST), 1); if (ret < 0) debug("error: fail to reset I2C controller\n");

@@ -97,9 +86,10 @@ static int reset_bus(struct uniphier_fi2c_regs __iomem *regs)

static int check_device_busy(struct uniphier_fi2c_regs __iomem *regs) {

• u32 val; int ret;

• ret = poll_status(&regs->sr, I2C_SR_DB);

• ret = readl_poll_timeout(&regs->sr, val, !(val & I2C_SR_DB), 100); if (ret < 0) { debug("error: device busy too long. reset...\n"); ret = reset_bus(regs);

@@ -138,15 +128,11 @@ 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--);

• int ret;

• if (wait < 0) {

• ret = readl_poll_timeout(&dev->regs->intr, irq, irq & flags,

• 		 dev->timeout);
  

• if (ret < 0) { debug("error: time out\n"); return ret; }

@@ -172,7 +158,7 @@ static int issue_stop(struct uniphier_fi2c_dev *dev, int old_ret) debug("stop condition\n"); writel(I2C_CR_MST | I2C_CR_STO, &dev->regs->cr);

• ret = poll_status(&dev->regs->sr, I2C_SR_DB);

• ret = check_device_busy(dev->regs); if (ret < 0) debug("error: device busy after operation\n");