Hi Leela,
On Thursday 31 of October 2013 11:30:50 Leela Krishna Amudala wrote:
> The syscon regmap interface is used to configure AUTOMATIC_WDT_RESET_DISABLE
> and MASK_WDT_RESET_REQUEST registers of PMU to mask/unmask enable/disable of
> watchdog in probe and s2r scenarios.
>
> Signed-off-by: Leela Krishna Amudala <l.krishna@xxxxxxxxxxx>
> ---
> .../devicetree/bindings/watchdog/samsung-wdt.txt | 22 ++-
> drivers/watchdog/s3c2410_wdt.c | 150 +++++++++++++++++---
> 2 files changed, 154 insertions(+), 18 deletions(-)
This patch looks better now, but there are still several issues remaining.
Please see my comments inline.
> diff --git a/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt b/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt
> index 2aa486c..0b8aa4b 100644
> --- a/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt
> +++ b/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt
> @@ -5,10 +5,30 @@ after a preset amount of time during which the WDT reset event has not
> occurred.
>
> Required properties:
> -- compatible : should be "samsung,s3c2410-wdt"
> +- compatible : should be one among the following
> + (a) "samsung,s3c2410-wdt" for Exynos4 and previous SoCs
> + (b) "samsung,exynos5250-wdt" for Exynos5250
> + (c) "samsung,exynos5420-wdt" for Exynos5420
> +
> - reg : base physical address of the controller and length of memory mapped
> region.
> - interrupts : interrupt number to the cpu.
> +- samsung,syscon-phandle : reference to syscon node (This property required only
> + in case of compatible being "samsung,exynos5250-wdt" or "samsung,exynos5420-wdt".
> + In case of Exynos5250 and 5420 this property points to syscon node holding the PMU
> + base address)
>
> Optional properties:
> - timeout-sec : contains the watchdog timeout in seconds.
> +
> +Example:
> +
> +watchdog@101D0000 {
> + compatible = "samsung,exynos5250-wdt";
> + reg = <0x101D0000 0x100>;
> + interrupts = <0 42 0>;
> + clocks = <&clock 336>;
> + clock-names = "watchdog";
> + samsung,sysreg = <&pmu_sys_reg>;
Shouldn't it be samsung,syscon-phandle?
> + status = "okay";
The status property is not a part of this binding, so can be dropped
from the example.
> +};
> diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
> index 23aad7c..235d160 100644
> --- a/drivers/watchdog/s3c2410_wdt.c
> +++ b/drivers/watchdog/s3c2410_wdt.c
> @@ -41,6 +41,8 @@
> #include <linux/slab.h>
> #include <linux/err.h>
> #include <linux/of.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/regmap.h>
>
> #define S3C2410_WTCON 0x00
> #define S3C2410_WTDAT 0x04
> @@ -61,6 +63,10 @@
> #define CONFIG_S3C2410_WATCHDOG_ATBOOT (0)
> #define CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME (15)
>
> +#define WDT_DISABLE_REG_OFFSET 0x0408
> +#define WDT_MASK_RESET_REG_OFFSET 0x040c
> +#define QUIRK_NEEDS_PMU_CONFIG (1 << 0)
> +
> static bool nowayout = WATCHDOG_NOWAYOUT;
> static int tmr_margin;
> static int tmr_atboot = CONFIG_S3C2410_WATCHDOG_ATBOOT;
> @@ -84,18 +90,61 @@ MODULE_PARM_DESC(soft_noboot, "Watchdog action, set to 1 to ignore reboots, "
> "0 to reboot (default 0)");
> MODULE_PARM_DESC(debug, "Watchdog debug, set to >1 for debug (default 0)");
>
> +struct s3c2410_wdt_variant {
> + int disable_reg;
> + int mask_reset_reg;
> + int mask_bit;
> + u32 quirks;
nit: To avoid the need of changing the indentation in future, if fields
with longer types gets added, I would simply separate type name from field
name using a single space.
> +};
> +
> struct s3c2410_wdt {
> - struct device *dev;
> - struct clk *clock;
> - void __iomem *reg_base;
> - unsigned int count;
> - spinlock_t lock;
> - unsigned long wtcon_save;
> - unsigned long wtdat_save;
> - struct watchdog_device wdt_device;
> - struct notifier_block freq_transition;
> + struct device *dev;
> + struct clk *clock;
> + void __iomem *reg_base;
> + unsigned int count;
> + spinlock_t lock;
> + unsigned long wtcon_save;
> + unsigned long wtdat_save;
> + struct watchdog_device wdt_device;
> + struct notifier_block freq_transition;
> + struct s3c2410_wdt_variant *pmu_config;
> + struct regmap *pmureg;
And here's an example of such (unnecessary) change. I believe it would
be better to keep indendation of other fields as is, use single space for
the new field and then change remaining fields in a separate patch,
outside of this series.
> +};
> +
> +#ifdef CONFIG_OF
> +static struct s3c2410_wdt_variant pmu_config_s3c2410 = {
static const struct
> + .disable_reg = 0x0,
> + .mask_reset_reg = 0x0,
> + .mask_bit = 0,
nit: I would simply omit the three fields above, since they are irrelevant
when QUIRK_NEEDS_PMU_CONFIG flag is not set. Not even saying that when
unspecified, they default to zero.
> + .quirks = 0
> };
>
> +static struct s3c2410_wdt_variant pmu_config_5250 = {
static const struct
> + .disable_reg = WDT_DISABLE_REG_OFFSET,
> + .mask_reset_reg = WDT_MASK_RESET_REG_OFFSET,
> + .mask_bit = 20,
> + .quirks = QUIRK_NEEDS_PMU_CONFIG
> +};
> +
> +static struct s3c2410_wdt_variant pmu_config_5420 = {
static const struct
> + .disable_reg = WDT_DISABLE_REG_OFFSET,
> + .mask_reset_reg = WDT_MASK_RESET_REG_OFFSET,
> + .mask_bit = 0,
> + .quirks = QUIRK_NEEDS_PMU_CONFIG
> +};
> +
> +static const struct of_device_id s3c2410_wdt_match[] = {
> + { .compatible = "samsung,s3c2410-wdt",
> + .data = (struct s3c2410_wdt_variant *) &pmu_config_s3c2410 },
No need for the cast.
> + { .compatible = "samsung,exynos5250-wdt",
> + .data = (struct s3c2410_wdt_variant *) &pmu_config_5250 },
Ditto.
> + { .compatible = "samsung,exynos5420-wdt",
> + .data = (struct s3c2410_wdt_variant *) &pmu_config_5420 },
Ditto.
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, s3c2410_wdt_match);
> +#endif
> +
> /* watchdog control routines */
>
> #define DBG(fmt, ...) \
> @@ -111,6 +160,47 @@ static inline struct s3c2410_wdt *freq_to_wdt(struct notifier_block *nb)
> return container_of(nb, struct s3c2410_wdt, freq_transition);
> }
>
> +static void s3c2410wdt_mask_and_disable_reset(int mask, struct s3c2410_wdt *wdt)
This function should return int and propagate possible errors to the caller.
Also the order of arguments is rather strange. The main context structure
is usually passed as first argument.
In addition, bool probably would make more sense for mask argument than int.
> +{
> + int ret;
> +
> + if (mask) {
> + ret = regmap_update_bits(wdt->pmureg,
> + wdt->pmu_config->disable_reg,
> + (1 << wdt->pmu_config->mask_bit),
> + (1 << wdt->pmu_config->mask_bit));
> + if (ret < 0) {
> + dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
> + return;
> + }
> + ret = regmap_update_bits(wdt->pmureg,
> + wdt->pmu_config->mask_reset_reg,
> + (1 << wdt->pmu_config->mask_bit),
> + (1 << wdt->pmu_config->mask_bit));
> + if (ret < 0) {
> + dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
> + return;
> + }
> + } else {
> + ret = regmap_update_bits(wdt->pmureg,
> + wdt->pmu_config->disable_reg,
> + (1 << wdt->pmu_config->mask_bit),
> + (0 << wdt->pmu_config->mask_bit));
> + if (ret < 0) {
> + dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
> + return;
> + }
> + ret = regmap_update_bits(wdt->pmureg,
> + wdt->pmu_config->mask_reset_reg,
> + (1 << wdt->pmu_config->mask_bit),
> + (0 << wdt->pmu_config->mask_bit));
> + if (ret < 0) {
> + dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
> + return;
> + }
> + }
This is not really what I imagined. You can greatly simplify this code
by refactoring it as follows:
static int s3c2410wdt_mask_and_disable_reset(struct s3c2410_wdt *wdt, bool mask)
{
int ret;
u32 mask_val = 1 << wdt->pmu_config->mask_bit;
u32 val = 0;
if (mask)
val = mask_val;
ret = regmap_update_bits(wdt->pmureg,
wdt->pmu_config->disable_reg,
mask_val, val);
if (ret < 0) {
dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
return ret;
}
ret = regmap_update_bits(wdt->pmureg,
wdt->pmu_config->mask_reset_reg,
mask_val, val);
if (ret < 0) {
dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
return ret;
}
return 0;
}
> +}
> +
> static int s3c2410wdt_keepalive(struct watchdog_device *wdd)
> {
> struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
> @@ -332,6 +422,15 @@ static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt)
> }
> #endif
>
> +/* s3c2410_get_wdt_driver_data */
> +static inline struct s3c2410_wdt_variant *
const struct
> +get_wdt_drv_data(struct platform_device *pdev)
> +{
> + const struct of_device_id *match;
> + match = of_match_node(s3c2410_wdt_match, pdev->dev.of_node);
> + return (struct s3c2410_wdt_variant *)match->data;
This function does not handle non-DT cases, which will cause a NULL pointer
dereference when the device is instantiated from a board file.
> +}
> +
> static int s3c2410wdt_probe(struct platform_device *pdev)
> {
> struct device *dev;
> @@ -354,6 +453,16 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
> spin_lock_init(&wdt->lock);
> wdt->wdt_device = s3c2410_wdd;
>
> + wdt->pmu_config = (struct s3c2410_wdt_variant *) get_wdt_drv_data(pdev);
No need for type cast here.
> + if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG) {
> + wdt->pmureg = syscon_regmap_lookup_by_phandle(dev->of_node,
> + "samsung,syscon-phandle");
> + if (IS_ERR(wdt->pmureg)) {
> + dev_err(dev, "syscon regmap lookup failed.\n");
> + return PTR_ERR(wdt->pmureg);
> + }
> + }
> +
> wdt_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
> if (wdt_irq == NULL) {
> dev_err(dev, "no irq resource specified\n");
> @@ -444,6 +553,9 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
> (wtcon & S3C2410_WTCON_RSTEN) ? "en" : "dis",
> (wtcon & S3C2410_WTCON_INTEN) ? "en" : "dis");
>
> + if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG)
> + s3c2410wdt_mask_and_disable_reset(0, wdt);
Error should be handled here. Also false would be better than 0 here.
> +
> return 0;
>
> err_cpufreq:
> @@ -461,6 +573,9 @@ static int s3c2410wdt_remove(struct platform_device *dev)
> {
> struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
>
> + if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG)
> + s3c2410wdt_mask_and_disable_reset(1, wdt);
Error should be handled here. Also true would be better than 1 here.
> +
> watchdog_unregister_device(&wdt->wdt_device);
>
> s3c2410wdt_cpufreq_deregister(wdt);
> @@ -475,6 +590,9 @@ static void s3c2410wdt_shutdown(struct platform_device *dev)
> {
> struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
>
> + if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG)
> + s3c2410wdt_mask_and_disable_reset(1, wdt);
Error should be handled here. Also true would be better than 1 here.
> +
> s3c2410wdt_stop(&wdt->wdt_device);
> }
>
> @@ -488,6 +606,9 @@ static int s3c2410wdt_suspend(struct device *dev)
> wdt->wtcon_save = readl(wdt->reg_base + S3C2410_WTCON);
> wdt->wtdat_save = readl(wdt->reg_base + S3C2410_WTDAT);
>
> + if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG)
> + s3c2410wdt_mask_and_disable_reset(1, wdt);
Error should be handled here. Also true would be better than 1 here.
> +
> /* Note that WTCNT doesn't need to be saved. */
> s3c2410wdt_stop(&wdt->wdt_device);
>
> @@ -503,6 +624,9 @@ static int s3c2410wdt_resume(struct device *dev)
> writel(wdt->wtdat_save, wdt->reg_base + S3C2410_WTCNT);/* Reset count */
> writel(wdt->wtcon_save, wdt->reg_base + S3C2410_WTCON);
>
> + if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG)
> + s3c2410wdt_mask_and_disable_reset(0, wdt);
Error should be handled here. Also false would be better than 0 here.
Best regards,
Tomasz
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