[08/15] wdt: dw: Add driver-model support

Commit Message

Jagan Teki July 29, 2019, 7:47 a.m. UTC

Add driver-model code for designware watchdog.

Cc: Chin Liang See <[e-mail]>
Cc: Andy Shevchenko <[e-mail]>
Signed-off-by: Jagan Teki <[e-mail]>
---
 drivers/watchdog/designware_wdt.c | 114 +++++++++++++++++++++++++++++-
 1 file changed, 113 insertions(+), 1 deletion(-)

Comments

Andy Shevchenko July 29, 2019, 9:09 a.m. UTC | #1

On Mon, Jul 29, 2019 at 10:56 AM Jagan Teki <[e-mail]> wrote:
>
> Add driver-model code for designware watchdog.

> +/*
> + * Set the watchdog time interval.
> + * Counter is 32 bit.
> + */
> +static int dw_wdt_set_timeout(struct dw_wdt *dw, unsigned int timeout)
> +{
> +       signed int i;
> +
> +       /* calculate the timeout range value */
> +       i = (log_2_n_round_up(timeout * dw->clk_rate)) - 16;

Redundant parenthesis.

> +       if (i > 15)
> +               i = 15;
> +       if (i < 0)
> +               i = 0;

Use clamp_t().

> +
> +       writel((i | (i << 4)), dw->regs + DW_WDT_TORR);
> +
> +       return 0;
> +}


> +       ret = clk_get_by_index(dev, 0, &clk);
> +       if (!ret)
> +               dw->clk_rate = clk_get_rate(&clk);
> +       else
> +               return -EINVAL;

Why not to use traditional pattern, i.e.

  if (ret)
    return -ERRNO;

Patch

diff --git a/drivers/watchdog/designware_wdt.c b/drivers/watchdog/designware_wdt.c
index 2979fda44e..4efbb25f86 100644
--- a/drivers/watchdog/designware_wdt.c
+++ b/drivers/watchdog/designware_wdt.c
@@ -4,7 +4,6 @@ 
  */
 
 #include <common.h>
-#include <watchdog.h>
 #include <asm/io.h>
 #include <asm/utils.h>
 
@@ -16,6 +15,117 @@ 
 #define DW_WDT_CR_RMOD_OFFSET	0x01
 #define DW_WDT_CRR_RESTART_VAL	0x76
 
+#ifdef CONFIG_WDT
+
+#include <dm.h>
+#include <wdt.h>
+#include <clk.h>
+
+struct dw_wdt {
+	void __iomem *regs;
+	unsigned long clk_rate;
+};
+
+static inline int dw_wdt_is_enabled(struct dw_wdt *dw)
+{
+	return readl(dw->regs + DW_WDT_CR) & DW_WDT_CR_RMOD_OFFSET;
+}
+
+/*
+ * Set the watchdog time interval.
+ * Counter is 32 bit.
+ */
+static int dw_wdt_set_timeout(struct dw_wdt *dw, unsigned int timeout)
+{
+	signed int i;
+
+	/* calculate the timeout range value */
+	i = (log_2_n_round_up(timeout * dw->clk_rate)) - 16;
+	if (i > 15)
+		i = 15;
+	if (i < 0)
+		i = 0;
+
+	writel((i | (i << 4)), dw->regs + DW_WDT_TORR);
+
+	return 0;
+}
+
+static void dw_wdt_enable(struct dw_wdt *dw)
+{
+	u32 val = readl(dw->regs + DW_WDT_CR);
+
+	/* Enable watchdog */
+	val |= DW_WDT_CR_RMOD_OFFSET;
+	writel(val, dw->regs + DW_WDT_CR);
+}
+
+static int dw_wdt_reset(struct udevice *dev)
+{
+	struct dw_wdt *dw = dev_get_priv(dev);
+
+	if (dw_wdt_is_enabled(dw))
+		writel(DW_WDT_CRR_RESTART_VAL, dw->regs + DW_WDT_CRR);
+	else
+		dw_wdt_enable(dw);
+
+	return 0;
+}
+
+static int dw_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
+{
+	struct dw_wdt *dw = dev_get_priv(dev);
+
+	dw_wdt_set_timeout(dw, timeout);
+	dw_wdt_enable(dw);
+
+	return 0;
+}
+
+static int dw_wdt_probe(struct udevice *dev)
+{
+	struct dw_wdt *dw = dev_get_priv(dev);
+	struct clk clk;
+	int ret;
+
+	dw->regs = dev_remap_addr(dev);
+	if (!dw->regs)
+		return -EINVAL;
+
+	ret = clk_get_by_index(dev, 0, &clk);
+	if (!ret)
+		dw->clk_rate = clk_get_rate(&clk);
+	else
+		return -EINVAL;
+
+	dw_wdt_reset(dev);
+
+	return 0;
+}
+
+static const struct wdt_ops dw_wdt_ops = {
+	.reset = dw_wdt_reset,
+	.start = dw_wdt_start,
+};
+
+static const struct udevice_id dw_wdt_ids[] = {
+	{ .compatible = "snps,dw-wdt" },
+	{ /* sentinel */ }
+};
+
+U_BOOT_DRIVER(dw_wdt) = {
+	.name = "dw_wdt",
+	.id = UCLASS_WDT,
+	.of_match = dw_wdt_ids,
+	.ops = &dw_wdt_ops,
+	.priv_auto_alloc_size = sizeof(struct dw_wdt),
+	.probe = dw_wdt_probe,
+};
+
+#else
+
+#include <watchdog.h>
+
 /*
  * Set the watchdog time interval.
  * Counter is 32 bit.
@@ -70,3 +180,5 @@  void hw_watchdog_init(void)
 	hw_watchdog_reset();
 }
 #endif
+
+#endif /* CONFIG_WDT */