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

From: Guenter Roeck
Date: Thu Apr 03 2014 - 12:36:23 EST


On Thu, Apr 03, 2014 at 09:04:19AM +0800, Xiubo Li wrote:
> 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);

This patch causes the following buiild failure:

Building arm:imx_v4_v5_defconfig ... failed
--------------
Error log:
drivers/built-in.o: In function `imx2_wdt_probe':
clk-composite.c:(.init.text+0x82c4): undefined reference to
`devm_regmap_init_mmio_clk'
make: *** [vmlinux] Error 1
--------------

This is on top of

b33ce44 Merge branch 'for-3.15/drivers' of git://git.kernel.dk/linux-block

Does it have build dependencies on code which is (or was) not yet available
in mainline ?

Thanks,
Guenter
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