[PATCHv4 2/2] watchdog: imx2_wdt: convert to use regmap API.

From: Xiubo Li
Date: Wed Apr 02 2014 - 21:49:02 EST


This watchdog driver will be working on IMX2+, Vybrid, LS1, LS2+
platforms, and will be in different endianness mode in those SoCs:

SoCs CPU endian mode WDT endian mode
------------------------------------------------
IMX2+ LE LE
Vybird LE LE
LS1 LE BE
LS2 LE LE

Other possible SoCs:
SoCs CPU endian mode WDT endian mode
------------------------------------------------
Soc1 BE BE
Soc2 BE LE

And also the watchdog's registers will be 32-bits for some versions,
and though it is 16-bits in IMX2+, Vybird and LS+.

Using the regmap APIs, could be more easy to support different
endianness and also more easy to support 32-bits version...

Signed-off-by: Xiubo Li <Li.Xiubo@xxxxxxxxxxxxx>
Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Cc: Shawn Guo <shawn.guo@xxxxxxxxxx>
---
drivers/watchdog/imx2_wdt.c | 50 +++++++++++++++++++++++++++++----------------
1 file changed, 32 insertions(+), 18 deletions(-)

diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c
index 1795922..76fa724 100644
--- a/drivers/watchdog/imx2_wdt.c
+++ b/drivers/watchdog/imx2_wdt.c
@@ -31,6 +31,7 @@
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/platform_device.h>
+#include <linux/regmap.h>
#include <linux/timer.h>
#include <linux/uaccess.h>
#include <linux/watchdog.h>
@@ -61,7 +62,7 @@

static struct {
struct clk *clk;
- void __iomem *base;
+ struct regmap *regmap;
unsigned timeout;
unsigned long status;
struct timer_list timer; /* Pings the watchdog when closed */
@@ -87,7 +88,9 @@ static const struct watchdog_info imx2_wdt_info = {

static inline void imx2_wdt_setup(void)
{
- u16 val = __raw_readw(imx2_wdt.base + IMX2_WDT_WCR);
+ u32 val;
+
+ regmap_read(imx2_wdt.regmap, IMX2_WDT_WCR, &val);

/* Suspend timer in low power mode, write once-only */
val |= IMX2_WDT_WCR_WDZST;
@@ -100,17 +103,17 @@ static inline void imx2_wdt_setup(void)
/* Set the watchdog's Time-Out value */
val |= WDOG_SEC_TO_COUNT(imx2_wdt.timeout);

- __raw_writew(val, imx2_wdt.base + IMX2_WDT_WCR);
+ regmap_write(imx2_wdt.regmap, IMX2_WDT_WCR, val);

/* enable the watchdog */
val |= IMX2_WDT_WCR_WDE;
- __raw_writew(val, imx2_wdt.base + IMX2_WDT_WCR);
+ regmap_write(imx2_wdt.regmap, IMX2_WDT_WCR, val);
}

static inline void imx2_wdt_ping(void)
{
- __raw_writew(IMX2_WDT_SEQ1, imx2_wdt.base + IMX2_WDT_WSR);
- __raw_writew(IMX2_WDT_SEQ2, imx2_wdt.base + IMX2_WDT_WSR);
+ regmap_write(imx2_wdt.regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ1);
+ regmap_write(imx2_wdt.regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ2);
}

static void imx2_wdt_timer_ping(unsigned long arg)
@@ -143,12 +146,8 @@ static void imx2_wdt_stop(void)

static void imx2_wdt_set_timeout(int new_timeout)
{
- u16 val = __raw_readw(imx2_wdt.base + IMX2_WDT_WCR);
-
- /* set the new timeout value in the WSR */
- val &= ~IMX2_WDT_WCR_WT;
- val |= WDOG_SEC_TO_COUNT(new_timeout);
- __raw_writew(val, imx2_wdt.base + IMX2_WDT_WCR);
+ regmap_update_bits(imx2_wdt.regmap, IMX2_WDT_WCR, IMX2_WDT_WCR_WT,
+ WDOG_SEC_TO_COUNT(new_timeout));
}

static int imx2_wdt_open(struct inode *inode, struct file *file)
@@ -181,7 +180,7 @@ static long imx2_wdt_ioctl(struct file *file, unsigned int cmd,
void __user *argp = (void __user *)arg;
int __user *p = argp;
int new_value;
- u16 val;
+ u32 val;

switch (cmd) {
case WDIOC_GETSUPPORT:
@@ -192,7 +191,7 @@ static long imx2_wdt_ioctl(struct file *file, unsigned int cmd,
return put_user(0, p);

case WDIOC_GETBOOTSTATUS:
- val = __raw_readw(imx2_wdt.base + IMX2_WDT_WRSR);
+ regmap_read(imx2_wdt.regmap, IMX2_WDT_WRSR, &val);
new_value = val & IMX2_WDT_WRSR_TOUT ? WDIOF_CARDRESET : 0;
return put_user(new_value, p);

@@ -255,15 +254,30 @@ static struct miscdevice imx2_wdt_miscdev = {
.fops = &imx2_wdt_fops,
};

+static struct regmap_config imx2_wdt_regmap_config = {
+ .reg_bits = 16,
+ .reg_stride = 2,
+ .val_bits = 16,
+ .max_register = 0x8,
+};
+
static int __init imx2_wdt_probe(struct platform_device *pdev)
{
- int ret;
struct resource *res;
+ void __iomem *base;
+ int ret;

res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- imx2_wdt.base = devm_ioremap_resource(&pdev->dev, res);
- if (IS_ERR(imx2_wdt.base))
- return PTR_ERR(imx2_wdt.base);
+ base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ imx2_wdt.regmap = devm_regmap_init_mmio_clk(&pdev->dev, NULL, base,
+ &imx2_wdt_regmap_config);
+ if (IS_ERR(imx2_wdt.regmap)) {
+ dev_err(&pdev->dev, "regmap init failed\n");
+ return PTR_ERR(imx2_wdt.regmap);
+ }

imx2_wdt.clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(imx2_wdt.clk)) {
--
1.8.4


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