Re: [PATCH 2/3] watchdog: jz4740: Use regmap provided by TCU driver

[Guenter Roeck <linux@roeck-us.net>]

On Fri, Aug 09, 2019 at 01:59:29PM +0200, Paul Cercueil wrote:
> Since we broke the ABI by changing the clock, the driver was also
> updated to use the regmap provided by the TCU driver.
> 
> Signed-off-by: Paul Cercueil <paul@crapouillou.net>
> Reviewed-by: Guenter Roeck <linux@roeck-us.net>
> Tested-by: Mathieu Malaterre <malat@debian.org>
> Tested-by: Artur Rojek <contact@artur-rojek.eu>

Acked-by: Guenter Roeck <linux@roeck-us.net>

> ---
>  drivers/watchdog/Kconfig      |  1 +
>  drivers/watchdog/jz4740_wdt.c | 36 +++++++++++++++++++----------------
>  2 files changed, 21 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index 820d8a472310..78411609048b 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -1647,6 +1647,7 @@ config JZ4740_WDT
>  	depends on MACH_JZ4740 || MACH_JZ4780
>  	depends on COMMON_CLK
>  	select WATCHDOG_CORE
> +	select MFD_SYSCON
>  	help
>  	  Hardware driver for the built-in watchdog timer on Ingenic jz4740 SoCs.
>  
> diff --git a/drivers/watchdog/jz4740_wdt.c b/drivers/watchdog/jz4740_wdt.c
> index 07fbd9d96e84..bdf9564efa29 100644
> --- a/drivers/watchdog/jz4740_wdt.c
> +++ b/drivers/watchdog/jz4740_wdt.c
> @@ -5,6 +5,7 @@
>   */
>  
>  #include <linux/mfd/ingenic-tcu.h>
> +#include <linux/mfd/syscon.h>
>  #include <linux/module.h>
>  #include <linux/moduleparam.h>
>  #include <linux/types.h>
> @@ -17,6 +18,7 @@
>  #include <linux/slab.h>
>  #include <linux/err.h>
>  #include <linux/of.h>
> +#include <linux/regmap.h>
>  
>  #define DEFAULT_HEARTBEAT 5
>  #define MAX_HEARTBEAT     2048
> @@ -36,7 +38,7 @@ MODULE_PARM_DESC(heartbeat,
>  
>  struct jz4740_wdt_drvdata {
>  	struct watchdog_device wdt;
> -	void __iomem *base;
> +	struct regmap *map;
>  	struct clk *clk;
>  	unsigned long clk_rate;
>  };
> @@ -45,7 +47,8 @@ static int jz4740_wdt_ping(struct watchdog_device *wdt_dev)
>  {
>  	struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
>  
> -	writew(0x0, drvdata->base + TCU_REG_WDT_TCNT);
> +	regmap_write(drvdata->map, TCU_REG_WDT_TCNT, 0);
> +
>  	return 0;
>  }
>  
> @@ -54,16 +57,16 @@ static int jz4740_wdt_set_timeout(struct watchdog_device *wdt_dev,
>  {
>  	struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
>  	u16 timeout_value = (u16)(drvdata->clk_rate * new_timeout);
> -	u8 tcer;
> +	unsigned int tcer;
>  
> -	tcer = readb(drvdata->base + TCU_REG_WDT_TCER);
> -	writeb(0x0, drvdata->base + TCU_REG_WDT_TCER);
> +	regmap_read(drvdata->map, TCU_REG_WDT_TCER, &tcer);
> +	regmap_write(drvdata->map, TCU_REG_WDT_TCER, 0);
>  
> -	writew((u16)timeout_value, drvdata->base + TCU_REG_WDT_TDR);
> -	writew(0x0, drvdata->base + TCU_REG_WDT_TCNT);
> +	regmap_write(drvdata->map, TCU_REG_WDT_TDR, timeout_value);
> +	regmap_write(drvdata->map, TCU_REG_WDT_TCNT, 0);
>  
>  	if (tcer & TCU_WDT_TCER_TCEN)
> -		writeb(TCU_WDT_TCER_TCEN, drvdata->base + TCU_REG_WDT_TCER);
> +		regmap_write(drvdata->map, TCU_REG_WDT_TCER, TCU_WDT_TCER_TCEN);
>  
>  	wdt_dev->timeout = new_timeout;
>  	return 0;
> @@ -72,20 +75,20 @@ static int jz4740_wdt_set_timeout(struct watchdog_device *wdt_dev,
>  static int jz4740_wdt_start(struct watchdog_device *wdt_dev)
>  {
>  	struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
> +	unsigned int tcer;
>  	int ret;
> -	u8 tcer;
>  
>  	ret = clk_prepare_enable(drvdata->clk);
>  	if (ret)
>  		return ret;
>  
> -	tcer = readb(drvdata->base + TCU_REG_WDT_TCER);
> +	regmap_read(drvdata->map, TCU_REG_WDT_TCER, &tcer);
>  
>  	jz4740_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
>  
>  	/* Start watchdog if it wasn't started already */
>  	if (!(tcer & TCU_WDT_TCER_TCEN))
> -		writeb(TCU_WDT_TCER_TCEN, drvdata->base + TCU_REG_WDT_TCER);
> +		regmap_write(drvdata->map, TCU_REG_WDT_TCER, TCU_WDT_TCER_TCEN);
>  
>  	return 0;
>  }
> @@ -94,7 +97,7 @@ static int jz4740_wdt_stop(struct watchdog_device *wdt_dev)
>  {
>  	struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
>  
> -	writeb(0x0, drvdata->base + TCU_REG_WDT_TCER);
> +	regmap_write(drvdata->map, TCU_REG_WDT_TCER, 0);
>  	clk_disable_unprepare(drvdata->clk);
>  
>  	return 0;
> @@ -136,7 +139,6 @@ static int jz4740_wdt_probe(struct platform_device *pdev)
>  	struct device *dev = &pdev->dev;
>  	struct jz4740_wdt_drvdata *drvdata;
>  	struct watchdog_device *jz4740_wdt;
> -	struct resource	*res;
>  	long rate;
>  	int ret;
>  
> @@ -173,9 +175,11 @@ static int jz4740_wdt_probe(struct platform_device *pdev)
>  	watchdog_set_nowayout(jz4740_wdt, nowayout);
>  	watchdog_set_drvdata(jz4740_wdt, drvdata);
>  
> -	drvdata->base = devm_platform_ioremap_resource(pdev, 0);
> -	if (IS_ERR(drvdata->base))
> -		return PTR_ERR(drvdata->base);
> +	drvdata->map = device_node_to_regmap(dev->parent->of_node);
> +	if (!drvdata->map) {
> +		dev_err(dev, "regmap not found\n");
> +		return -EINVAL;
> +	}
>  
>  	return devm_watchdog_register_device(dev, &drvdata->wdt);
>  }