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i2c: uniphier-f: use readl_poll_timeout() to poll registers 

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>
This commit is contained in:
Masahiro Yamada 2017-01-28 06:53:56 +09:00
parent 800acb850e
commit 68578582ab
1 changed files with 10 additions and 24 deletions
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34
drivers/i2c/i2c-uniphier-f.c
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@ -9,6 +9,7 @@
#include <common.h> #include <common.h>
#include <linux/types.h> #include <linux/types.h>
#include <linux/io.h> #include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/sizes.h> #include <linux/sizes.h>
#include <linux/errno.h> #include <linux/errno.h>
#include <dm/device.h> #include <dm/device.h>
@ -69,26 +70,14 @@ struct uniphier_fi2c_dev {
unsigned long timeout; /* time out (us) */ 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) static int reset_bus(struct uniphier_fi2c_regs __iomem *regs)
{ {
u32 val;
int ret; int ret;
/* bus forcible reset */ /* bus forcible reset */
writel(I2C_RST_RST, &regs->rst); 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) if (ret < 0)
debug("error: fail to reset I2C controller\n"); 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) static int check_device_busy(struct uniphier_fi2c_regs __iomem *regs)
{ {
u32 val;
int ret; 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) { if (ret < 0) {
debug("error: device busy too long. reset...\n"); debug("error: device busy too long. reset...\n");
ret = reset_bus(regs); ret = reset_bus(regs);
@ -138,15 +128,11 @@ static int wait_for_irq(struct uniphier_fi2c_dev *dev, u32 flags,
bool *stop) bool *stop)
{ {
u32 irq; u32 irq;
unsigned long wait = dev->timeout; int ret;
int ret = -EREMOTEIO;
do { ret = readl_poll_timeout(&dev->regs->intr, irq, irq & flags,
udelay(1); dev->timeout);
irq = readl(&dev->regs->intr); if (ret < 0) {
} while (!(irq & flags) && wait--);
if (wait < 0) {
debug("error: time out\n"); debug("error: time out\n");
return ret; return ret;
} }
@ -172,7 +158,7 @@ static int issue_stop(struct uniphier_fi2c_dev *dev, int old_ret)
debug("stop condition\n"); debug("stop condition\n");
writel(I2C_CR_MST | I2C_CR_STO, &dev->regs->cr); 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) if (ret < 0)
debug("error: device busy after operation\n"); debug("error: device busy after operation\n");