Re: [PATCH v2 6/9] watchdog: st_wdt: Add new driver for ST's LPC Watchdog

On Thu, 22 Jan 2015, Guenter Roeck wrote:

On 01/22/2015 03:56 AM, Lee Jones wrote:

quoted

Signed-off-by: David Paris <redacted>
Signed-off-by: Lee Jones <redacted>
---
 drivers/watchdog/Kconfig      |  13 ++
 drivers/watchdog/Makefile     |   1 +
 drivers/watchdog/st_lpc_wdt.c | 335 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 349 insertions(+)
 create mode 100644 drivers/watchdog/st_lpc_wdt.c

[...]

quoted

+struct st_wdog_syscfg {
+	struct regmap *regmap;

Hi David & Lee,

Why did you add the regmap pointer to this structure and not to st_wdog ?
It is not a configuration value, after all, and it is always dereferenced
through wt_wdog->syscfg. So all it does is to make the code more complicated.

Am I missing something ?

I guess it was just to group it all together, as it will all be used
at the same time:

	regmap_update_bits(st_wdog->syscfg->regmap,
			   st_wdog->syscfg->reset_type_reg,
			   st_wdog->syscfg->reset_type_mask,
			   st_wdog->warm_reset);

It really doesn't matter to me either way.

quoted

+	unsigned int reset_type_reg;
+	unsigned int reset_type_mask;
+	unsigned int enable_reg;
+	unsigned int enable_mask;
+};
+
+struct st_wdog {
+	void __iomem *base;
+	struct device *dev;
+	struct st_wdog_syscfg *syscfg;
+	struct clk *clk;
+	unsigned long clkrate;
+	bool warm_reset;
+};

[...]

quoted

+static int st_wdog_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+	struct device_node *np = pdev->dev.of_node;
+	struct st_wdog *st_wdog;
+	struct regmap *regmap;
+	struct resource *res;
+	struct clk *clk;
+	void __iomem *base;
+	uint32_t mode;
+	int ret;
+
+	ret = of_property_read_u32(np, "st,lpc-mode", &mode);
+	if (ret) {
+		dev_err(&pdev->dev, "An LPC mode must be provided\n");
+		return -EINVAL;
+	}
+
+	/* LPC can either run in RTC or WDT mode */
+	if (mode != ST_LPC_MODE_WDT)
+		return -ENODEV;
+
+	st_wdog = devm_kzalloc(&pdev->dev, sizeof(*st_wdog), GFP_KERNEL);
+	if (!st_wdog)
+		return -ENOMEM;
+
+	match = of_match_device(st_wdog_match, &pdev->dev);
+	if (!match) {
+		dev_err(&pdev->dev, "Couldn't match device\n");
+		return -ENODEV;
+	}
+	st_wdog->syscfg	= (struct st_wdog_syscfg *)match->data;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(base)) {
+		dev_err(&pdev->dev, "Failed to ioremap base\n");

devm_ioremap_resource already displays an error message, do this one is unnecessary.

You're right.  Will fix.

[...]

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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