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

[Heiko Schocher <hs@denx.de>]

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");
>
>

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