Re: [PATCH v2 2/2] Add PWM fan controller driver for LGM SoC

Hi Rahul,

On Thu, 2020-06-18 at 20:05 +0800, Rahul Tanwar wrote:

Intel Lightning Mountain(LGM) SoC contains a PWM fan controller.
This PWM controller does not have any other consumer, it is a
dedicated PWM controller for fan attached to the system. Add
driver for this PWM fan controller.

Signed-off-by: Rahul Tanwar <redacted>
---
 drivers/pwm/Kconfig         |   9 +
 drivers/pwm/Makefile        |   1 +
 drivers/pwm/pwm-intel-lgm.c | 400 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 410 insertions(+)
 create mode 100644 drivers/pwm/pwm-intel-lgm.c

[...]

[...]

+static int lgm_pwm_probe(struct platform_device *pdev)
+{
+	struct lgm_pwm_chip *pc;
+	struct device *dev = &pdev->dev;
+	void __iomem *io_base;
+	int ret;
+
+	pc = devm_kzalloc(dev, sizeof(*pc), GFP_KERNEL);
+	if (!pc)
+		return -ENOMEM;
+
+	io_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(io_base))
+		return PTR_ERR(io_base);
+
+	pc->regmap = devm_regmap_init_mmio(dev, io_base, &pwm_regmap_config);
+	if (IS_ERR(pc->regmap)) {
+		ret = PTR_ERR(pc->regmap);
+		dev_err(dev, "failed to init register map: %pe\n", pc->regmap);
+		return ret;
+	}
+
+	pc->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(pc->clk)) {
+		ret = PTR_ERR(pc->clk);
+		dev_err(dev, "failed to get clock: %pe\n", pc->clk);
+		return ret;
+	}
+
+	pc->rst = devm_reset_control_get(dev, NULL);
+	if (IS_ERR(pc->rst)) {
+		ret = PTR_ERR(pc->rst);
+		dev_err(dev, "failed to get reset control: %pe\n", pc->rst);
+		return ret;
+	}

Please use devm_reset_control_get_exclusive() to make it explicit an
that exclusive reset control is requested. Given how the reset control
is used, I think this driver could also use
devm_reset_control_get_shared() to potentially allow sharing a reset
line with other devices.

regards
Philipp