[PATCH v14 0/2] Add PWM support for Intel Keem Bay SoC

[PATCH v14 0/2] Add PWM support for Intel Keem Bay SoC

[vijayakannan.ayyathurai]

From: Vijayakannan Ayyathurai <vijayakannan.ayyathurai@intel.com>

Hi,

This patch set enables the support for PWM in the Intel Keem Bay SoC.
Keem Bay is an ARM based SoC, and the GPIO module allows
configuration of 6 PWM outputs.

Patch 1 adds the PWM driver and Patch 2 is for the required
Device Tree bindings documentation.

This driver was tested on the Keem Bay evaluation module board.

Thank you.

Regards,
Vijay

Changes since v13:
- Fix indentation error in dt-binding.
- Add maintainer name in dt-binding.

Changes since v12:
- Use devm_add_action_or_reset() as per Andy suggestion.
- Do the clk_prepare_enable() after all devm_ stuff as per Uwe suggestion.
- Optimize keembay_pwm_remove function.
- Simplify the error handling for pwmchip_add.
- In Kconfig, Use depends on ARCH_KEEMBAY || (ARM64 && COMPILE_TEST)
- Fix indentation error in dt-binding.
- Add Uwe's Reviewed-by tag and Vijay's Co-developed-by tag.

Changes since v11:
- Minor variable name change to match the api needs.
- Setup polarity as PWM_POLARITY_NORMAL.
- Add comment for LEADIN register usage.

Changes since v10:
- Update low time calculation formula as per Uwe.
- During distruct remove pwmchip first then disable the clock.

Changes since v9:
- Remove Reported-by tag from the commit log.

Changes since v8:
- Fix the compilation error reported by kernel test robot.
- Add the tag Reported-by: kernel test robot <lkp@intel.com>
- Minor correction in the pwm low time calculation formula.
- Rebase with 5.9-rc7

Changes since v7:
- Change the dependency as ARCH_KEEMBAY instead of ARM64 in Kconfig.
- Use DIV_ROUND_DOWN_ULL instead of DIV_ROUND_CLOSEST_ULL.
- Update the right formula as per Uwe.
- List the tags in chronological order.
- Add clk_disable_unprepare in the error paths.

Changes since v6:
- Add reviewed-by tag

Changes since v5:
- Reorder symbols/Kconfig in drivers/pwm/Kconfig and drivers/pwm/Makefile
- Use "Limitations" for consistency
- Add clk_prepare_enable()
- Reorder keembay_pwm_get_state() function call
- Rework if conditional for channel disablement in .apply()
- Remove channel disabling from .probe(), and clear LEADIN register bits
  in .apply instead
- Update commit message for Patch 1

Changes since v4:
- Add co-developed-by tag
- Include mod_devicetable.h and remove of.h
- Update comment with correct calulation for high/low time
- Fix missing return from dev_err_probe

Changes since v3:
- Removed variable for address and calculate in place instead
- Utilized u32_replace_bits() when updating KMB_PWM_LEADIN_OFFSET
- Utilized dev_err_probe() for error reporting
- Updated comments to use physical units
- Updated error check for pwmchip_add()

Changes since v2:
- Include documentation about HW limitation/behaviour
- Use hex values for KMB_PWM_COUNT_MAX
- Redefine register macros
- Utilize FIELD_GET/FIELD_PREP for calculating pwm_l/h_count and
  pwm_count
- Round up duty cycle/period values
- Get current hardware state in .apply instead of cached values
- Do a polarity check before .enabled
- Round high time/low time to closest value
- Set enable bit in KMB_PWM_LEADIN_OFFSET to 0 in probe
- Correct the naming for MODULE_ALIAS
- Add additionalProperties: false in DT bindings

Changes since v1:
- Updated licensing info, "clocks" property and example in DT bindings
- Updated name of DT bindings document to match compatible string
- Removed 1 patch for addition of new sysfs attribute "count"
- Added support for COMPILE_TEST in Kconfig
- Updated naming of defines and regmap attribute
- Updated calculation of waveform high time and low time
- Added range checking for waveform high/low time
- Implemented .get_state
- Removed register writes for lead-in and count values (left to default)
- Updated register access to single-access
- Folded keembay_pwm_enable/disable_channel,
  keembay_pwm_config_period/duty_cycle,
  and keembay_pwm_config into keembay_pwm_apply
- Updated error messages/error codes
- Removed pwm_disable from keembay_pwm_remove
- Removed clk_prepare/clk_enable/clk_disable from driver

Lai, Poey Seng (1):
  pwm: Add PWM driver for Intel Keem Bay

Vineetha G. Jaya Kumaran (1):
  dt-bindings: pwm: keembay: Add bindings for Intel Keem Bay PWM

 .../bindings/pwm/intel,keembay-pwm.yaml       |  47 ++++
 drivers/pwm/Kconfig                           |   9 +
 drivers/pwm/Makefile                          |   1 +
 drivers/pwm/pwm-keembay.c                     | 240 ++++++++++++++++++
 4 files changed, 297 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/intel,keembay-pwm.yaml
 create mode 100644 drivers/pwm/pwm-keembay.c


base-commit: 549738f15da0e5a00275977623be199fbbf7df50
prerequisite-patch-id: 0a348762b660d0d817b8e70cc71647e83173c78c
prerequisite-patch-id: 0c6072cfe492b078c44ec864b8f9d1c76eada93b
prerequisite-patch-id: 12b93428ee51a3d92ca973b928c0e0989f5d585e
--
2.17.1

[PATCH v14 1/2] pwm: Add PWM driver for Intel Keem Bay

[vijayakannan.ayyathurai]

From: Vijayakannan Ayyathurai <vijayakannan.ayyathurai@intel.com>

The Intel Keem Bay SoC requires PWM support.
Add the pwm-keembay driver to enable this.

Signed-off-by: Lai, Poey Seng <poey.seng.lai@intel.com>
Co-developed-by: Vineetha G. Jaya Kumaran <vineetha.g.jaya.kumaran@intel.com>
Signed-off-by: Vineetha G. Jaya Kumaran <vineetha.g.jaya.kumaran@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Co-developed-by: Vijayakannan Ayyathurai <vijayakannan.ayyathurai@intel.com>
Signed-off-by: Vijayakannan Ayyathurai <vijayakannan.ayyathurai@intel.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/pwm/Kconfig       |   9 ++
 drivers/pwm/Makefile      |   1 +
 drivers/pwm/pwm-keembay.c | 240 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 250 insertions(+)
 create mode 100644 drivers/pwm/pwm-keembay.c

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 7dbcf6973d33..c4f4a1c0a049 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -254,6 +254,15 @@ config PWM_JZ4740
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-jz4740.
 
+config PWM_KEEMBAY
+	tristate "Intel Keem Bay PWM driver"
+	depends on ARCH_KEEMBAY || (ARM64 && COMPILE_TEST)
+	help
+	  The platform driver for Intel Keem Bay PWM controller.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pwm-keembay.
+
 config PWM_LP3943
 	tristate "TI/National Semiconductor LP3943 PWM support"
 	depends on MFD_LP3943
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index 2c2ba0a03557..a1051122eb07 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_PWM_IMX27)		+= pwm-imx27.o
 obj-$(CONFIG_PWM_IMX_TPM)	+= pwm-imx-tpm.o
 obj-$(CONFIG_PWM_IQS620A)	+= pwm-iqs620a.o
 obj-$(CONFIG_PWM_JZ4740)	+= pwm-jz4740.o
+obj-$(CONFIG_PWM_KEEMBAY)	+= pwm-keembay.o
 obj-$(CONFIG_PWM_LP3943)	+= pwm-lp3943.o
 obj-$(CONFIG_PWM_LPC18XX_SCT)	+= pwm-lpc18xx-sct.o
 obj-$(CONFIG_PWM_LPC32XX)	+= pwm-lpc32xx.o
diff --git a/drivers/pwm/pwm-keembay.c b/drivers/pwm/pwm-keembay.c
new file mode 100644
index 000000000000..27023677330c
--- /dev/null
+++ b/drivers/pwm/pwm-keembay.c
@@ -0,0 +1,240 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Intel Keem Bay PWM driver
+ *
+ * Copyright (C) 2020 Intel Corporation
+ * Authors: Lai Poey Seng <poey.seng.lai@intel.com>
+ *          Vineetha G. Jaya Kumaran <vineetha.g.jaya.kumaran@intel.com>
+ *
+ * Limitations:
+ * - Upon disabling a channel, the currently running
+ *   period will not be completed. However, upon
+ *   reconfiguration of the duty cycle/period, the
+ *   currently running period will be completed first.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/regmap.h>
+
+#define KMB_TOTAL_PWM_CHANNELS		6
+#define KMB_PWM_COUNT_MAX		U16_MAX
+#define KMB_PWM_EN_BIT			BIT(31)
+
+/* Mask */
+#define KMB_PWM_HIGH_MASK		GENMASK(31, 16)
+#define KMB_PWM_LOW_MASK		GENMASK(15, 0)
+#define KMB_PWM_LEADIN_MASK		GENMASK(30, 0)
+
+/* PWM Register offset */
+#define KMB_PWM_LEADIN_OFFSET(ch)	(0x00 + 4 * (ch))
+#define KMB_PWM_HIGHLOW_OFFSET(ch)	(0x20 + 4 * (ch))
+
+struct keembay_pwm {
+	struct pwm_chip chip;
+	struct device *dev;
+	struct clk *clk;
+	void __iomem *base;
+};
+
+static inline struct keembay_pwm *to_keembay_pwm_dev(struct pwm_chip *chip)
+{
+	return container_of(chip, struct keembay_pwm, chip);
+}
+
+static void keembay_clk_unprepare(void *data)
+{
+	clk_disable_unprepare(data);
+}
+
+static int keembay_clk_enable(struct device *dev, struct clk *clk)
+{
+	int ret;
+
+	ret = clk_prepare_enable(clk);
+	if (ret)
+		return ret;
+
+	return devm_add_action_or_reset(dev, keembay_clk_unprepare, clk);
+}
+
+static inline void keembay_pwm_update_bits(struct keembay_pwm *priv, u32 mask,
+					   u32 val, u32 offset)
+{
+	u32 buff = readl(priv->base + offset);
+
+	buff = u32_replace_bits(buff, val, mask);
+	writel(buff, priv->base + offset);
+}
+
+static void keembay_pwm_enable(struct keembay_pwm *priv, int ch)
+{
+	keembay_pwm_update_bits(priv, KMB_PWM_EN_BIT, 1,
+				KMB_PWM_LEADIN_OFFSET(ch));
+}
+
+static void keembay_pwm_disable(struct keembay_pwm *priv, int ch)
+{
+	keembay_pwm_update_bits(priv, KMB_PWM_EN_BIT, 0,
+				KMB_PWM_LEADIN_OFFSET(ch));
+}
+
+static void keembay_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
+				  struct pwm_state *state)
+{
+	struct keembay_pwm *priv = to_keembay_pwm_dev(chip);
+	unsigned long long high, low;
+	unsigned long clk_rate;
+	u32 highlow;
+
+	clk_rate = clk_get_rate(priv->clk);
+
+	/* Read channel enabled status */
+	highlow = readl(priv->base + KMB_PWM_LEADIN_OFFSET(pwm->hwpwm));
+	if (highlow & KMB_PWM_EN_BIT)
+		state->enabled = true;
+	else
+		state->enabled = false;
+
+	/* Read period and duty cycle */
+	highlow = readl(priv->base + KMB_PWM_HIGHLOW_OFFSET(pwm->hwpwm));
+	low = FIELD_GET(KMB_PWM_LOW_MASK, highlow) * NSEC_PER_SEC;
+	high = FIELD_GET(KMB_PWM_HIGH_MASK, highlow) * NSEC_PER_SEC;
+	state->duty_cycle = DIV_ROUND_UP_ULL(high, clk_rate);
+	state->period = DIV_ROUND_UP_ULL(high + low, clk_rate);
+	state->polarity = PWM_POLARITY_NORMAL;
+}
+
+static int keembay_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			     const struct pwm_state *state)
+{
+	struct keembay_pwm *priv = to_keembay_pwm_dev(chip);
+	struct pwm_state current_state;
+	unsigned long long div;
+	unsigned long clk_rate;
+	u32 pwm_count = 0;
+	u16 high, low;
+
+	if (state->polarity != PWM_POLARITY_NORMAL)
+		return -ENOSYS;
+
+	/*
+	 * Configure the pwm repeat count as infinite at (15:0) and leadin
+	 * low time as 0 at (30:16), which is in terms of clock cycles.
+	 */
+	keembay_pwm_update_bits(priv, KMB_PWM_LEADIN_MASK, 0,
+				KMB_PWM_LEADIN_OFFSET(pwm->hwpwm));
+
+	keembay_pwm_get_state(chip, pwm, &current_state);
+
+	if (!state->enabled) {
+		if (current_state.enabled)
+			keembay_pwm_disable(priv, pwm->hwpwm);
+		return 0;
+	}
+
+	/*
+	 * The upper 16 bits and lower 16 bits of the KMB_PWM_HIGHLOW_OFFSET
+	 * register contain the high time and low time of waveform accordingly.
+	 * All the values are in terms of clock cycles.
+	 */
+
+	clk_rate = clk_get_rate(priv->clk);
+	div = clk_rate * state->duty_cycle;
+	div = DIV_ROUND_DOWN_ULL(div, NSEC_PER_SEC);
+	if (div > KMB_PWM_COUNT_MAX)
+		return -ERANGE;
+
+	high = div;
+	div = clk_rate * state->period;
+	div = DIV_ROUND_DOWN_ULL(div, NSEC_PER_SEC);
+	div = div - high;
+	if (div > KMB_PWM_COUNT_MAX)
+		return -ERANGE;
+
+	low = div;
+
+	pwm_count = FIELD_PREP(KMB_PWM_HIGH_MASK, high) |
+		    FIELD_PREP(KMB_PWM_LOW_MASK, low);
+
+	writel(pwm_count, priv->base + KMB_PWM_HIGHLOW_OFFSET(pwm->hwpwm));
+
+	if (state->enabled && !current_state.enabled)
+		keembay_pwm_enable(priv, pwm->hwpwm);
+
+	return 0;
+}
+
+static const struct pwm_ops keembay_pwm_ops = {
+	.owner = THIS_MODULE,
+	.apply = keembay_pwm_apply,
+	.get_state = keembay_pwm_get_state,
+};
+
+static int keembay_pwm_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct keembay_pwm *priv;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(priv->clk))
+		return dev_err_probe(dev, PTR_ERR(priv->clk), "Failed to get clock\n");
+
+	priv->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	ret = keembay_clk_enable(dev, priv->clk);
+	if (ret)
+		return ret;
+
+	priv->chip.base = -1;
+	priv->chip.dev = dev;
+	priv->chip.ops = &keembay_pwm_ops;
+	priv->chip.npwm = KMB_TOTAL_PWM_CHANNELS;
+
+	ret = pwmchip_add(&priv->chip);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to add PWM chip\n");
+
+	platform_set_drvdata(pdev, priv);
+
+	return 0;
+}
+
+static int keembay_pwm_remove(struct platform_device *pdev)
+{
+	struct keembay_pwm *priv = platform_get_drvdata(pdev);
+
+	return pwmchip_remove(&priv->chip);
+}
+
+static const struct of_device_id keembay_pwm_of_match[] = {
+	{ .compatible = "intel,keembay-pwm" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, keembay_pwm_of_match);
+
+static struct platform_driver keembay_pwm_driver = {
+	.probe	= keembay_pwm_probe,
+	.remove	= keembay_pwm_remove,
+	.driver	= {
+		.name = "pwm-keembay",
+		.of_match_table = keembay_pwm_of_match,
+	},
+};
+module_platform_driver(keembay_pwm_driver);
+
+MODULE_ALIAS("platform:pwm-keembay");
+MODULE_DESCRIPTION("Intel Keem Bay PWM driver");
+MODULE_LICENSE("GPL v2");
-- 
2.17.1

[PATCH v14 2/2] dt-bindings: pwm: keembay: Add bindings for Intel Keem Bay PWM

[vijayakannan.ayyathurai]

From: Vijayakannan Ayyathurai <vijayakannan.ayyathurai@intel.com>

Add PWM Device Tree bindings documentation for the Intel Keem Bay SoC.

Signed-off-by: Vineetha G. Jaya Kumaran <vineetha.g.jaya.kumaran@intel.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Vijayakannan Ayyathurai <vijayakannan.ayyathurai@intel.com>
---
 .../bindings/pwm/intel,keembay-pwm.yaml       | 47 +++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/intel,keembay-pwm.yaml

diff --git a/Documentation/devicetree/bindings/pwm/intel,keembay-pwm.yaml b/Documentation/devicetree/bindings/pwm/intel,keembay-pwm.yaml
new file mode 100644
index 000000000000..ff6880a02ce6
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/intel,keembay-pwm.yaml
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright (C) 2020 Intel Corporation
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pwm/intel,keembay-pwm.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Intel Keem Bay PWM Device Tree Bindings
+
+maintainers:
+  - Vijayakannan Ayyathurai <vijayakannan.ayyathurai@intel.com>
+
+allOf:
+  - $ref: pwm.yaml#
+
+properties:
+  compatible:
+    enum:
+      - intel,keembay-pwm
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  "#pwm-cells":
+    const: 2
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - '#pwm-cells'
+
+additionalProperties: false
+
+examples:
+  - |
+    #define KEEM_BAY_A53_GPIO
+
+    pwm@203200a0 {
+        compatible = "intel,keembay-pwm";
+        reg = <0x203200a0 0xe8>;
+        clocks = <&scmi_clk KEEM_BAY_A53_GPIO>;
+        #pwm-cells = <2>;
+    };
-- 
2.17.1

RE: [PATCH v14 1/2] pwm: Add PWM driver for Intel Keem Bay

[Ayyathurai, Vijayakannan]

Hi,

> From: Ayyathurai, Vijayakannan <vijayakannan.ayyathurai@intel.com>
> Sent: Thursday, 22 October, 2020 3:15 PM
> To: thierry.reding@gmail.com; u.kleine-koenig@pengutronix.de;
> robh+dt@kernel.org
> Cc: linux-pwm@vger.kernel.org; devicetree@vger.kernel.org; Wan Mohamad,
> Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad@intel.com>;
> andriy.shevchenko@linux.intel.com; mgross@linux.intel.com; Raja
> Subramanian, Lakshmi Bai <lakshmi.bai.raja.subramanian@intel.com>;
> Ayyathurai, Vijayakannan <vijayakannan.ayyathurai@intel.com>
> Subject: [PATCH v14 1/2] pwm: Add PWM driver for Intel Keem Bay
> 
> From: Vijayakannan Ayyathurai <vijayakannan.ayyathurai@intel.com>
> 
> The Intel Keem Bay SoC requires PWM support.
> Add the pwm-keembay driver to enable this.
> 
> Signed-off-by: Lai, Poey Seng <poey.seng.lai@intel.com>
> Co-developed-by: Vineetha G. Jaya Kumaran
> <vineetha.g.jaya.kumaran@intel.com>
> Signed-off-by: Vineetha G. Jaya Kumaran
> <vineetha.g.jaya.kumaran@intel.com>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Co-developed-by: Vijayakannan Ayyathurai
> <vijayakannan.ayyathurai@intel.com>
> Signed-off-by: Vijayakannan Ayyathurai
> <vijayakannan.ayyathurai@intel.com>
> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---

Please consider review this patch and let me know if there is any further feedback.

I have also compiled and tested this patch with
	tag: v5.10-rc2	(3cea11cd5e3b00d91caf0b4730194039b45c5891)

Thanks in advance,
Vijay

Re: [PATCH v14 0/2] Add PWM support for Intel Keem Bay SoC

[Thierry Reding]

[-- Attachment #1: Type: text/plain, Size: 5516 bytes --]

On Thu, Oct 22, 2020 at 03:14:45PM +0800, vijayakannan.ayyathurai@intel.com wrote:
> From: Vijayakannan Ayyathurai <vijayakannan.ayyathurai@intel.com>
> 
> Hi,
> 
> This patch set enables the support for PWM in the Intel Keem Bay SoC.
> Keem Bay is an ARM based SoC, and the GPIO module allows
> configuration of 6 PWM outputs.
> 
> Patch 1 adds the PWM driver and Patch 2 is for the required
> Device Tree bindings documentation.
> 
> This driver was tested on the Keem Bay evaluation module board.
> 
> Thank you.
> 
> Regards,
> Vijay
> 
> Changes since v13:
> - Fix indentation error in dt-binding.
> - Add maintainer name in dt-binding.
> 
> Changes since v12:
> - Use devm_add_action_or_reset() as per Andy suggestion.
> - Do the clk_prepare_enable() after all devm_ stuff as per Uwe suggestion.
> - Optimize keembay_pwm_remove function.
> - Simplify the error handling for pwmchip_add.
> - In Kconfig, Use depends on ARCH_KEEMBAY || (ARM64 && COMPILE_TEST)
> - Fix indentation error in dt-binding.
> - Add Uwe's Reviewed-by tag and Vijay's Co-developed-by tag.
> 
> Changes since v11:
> - Minor variable name change to match the api needs.
> - Setup polarity as PWM_POLARITY_NORMAL.
> - Add comment for LEADIN register usage.
> 
> Changes since v10:
> - Update low time calculation formula as per Uwe.
> - During distruct remove pwmchip first then disable the clock.
> 
> Changes since v9:
> - Remove Reported-by tag from the commit log.
> 
> Changes since v8:
> - Fix the compilation error reported by kernel test robot.
> - Add the tag Reported-by: kernel test robot <lkp@intel.com>
> - Minor correction in the pwm low time calculation formula.
> - Rebase with 5.9-rc7
> 
> Changes since v7:
> - Change the dependency as ARCH_KEEMBAY instead of ARM64 in Kconfig.
> - Use DIV_ROUND_DOWN_ULL instead of DIV_ROUND_CLOSEST_ULL.
> - Update the right formula as per Uwe.
> - List the tags in chronological order.
> - Add clk_disable_unprepare in the error paths.
> 
> Changes since v6:
> - Add reviewed-by tag
> 
> Changes since v5:
> - Reorder symbols/Kconfig in drivers/pwm/Kconfig and drivers/pwm/Makefile
> - Use "Limitations" for consistency
> - Add clk_prepare_enable()
> - Reorder keembay_pwm_get_state() function call
> - Rework if conditional for channel disablement in .apply()
> - Remove channel disabling from .probe(), and clear LEADIN register bits
>   in .apply instead
> - Update commit message for Patch 1
> 
> Changes since v4:
> - Add co-developed-by tag
> - Include mod_devicetable.h and remove of.h
> - Update comment with correct calulation for high/low time
> - Fix missing return from dev_err_probe
> 
> Changes since v3:
> - Removed variable for address and calculate in place instead
> - Utilized u32_replace_bits() when updating KMB_PWM_LEADIN_OFFSET
> - Utilized dev_err_probe() for error reporting
> - Updated comments to use physical units
> - Updated error check for pwmchip_add()
> 
> Changes since v2:
> - Include documentation about HW limitation/behaviour
> - Use hex values for KMB_PWM_COUNT_MAX
> - Redefine register macros
> - Utilize FIELD_GET/FIELD_PREP for calculating pwm_l/h_count and
>   pwm_count
> - Round up duty cycle/period values
> - Get current hardware state in .apply instead of cached values
> - Do a polarity check before .enabled
> - Round high time/low time to closest value
> - Set enable bit in KMB_PWM_LEADIN_OFFSET to 0 in probe
> - Correct the naming for MODULE_ALIAS
> - Add additionalProperties: false in DT bindings
> 
> Changes since v1:
> - Updated licensing info, "clocks" property and example in DT bindings
> - Updated name of DT bindings document to match compatible string
> - Removed 1 patch for addition of new sysfs attribute "count"
> - Added support for COMPILE_TEST in Kconfig
> - Updated naming of defines and regmap attribute
> - Updated calculation of waveform high time and low time
> - Added range checking for waveform high/low time
> - Implemented .get_state
> - Removed register writes for lead-in and count values (left to default)
> - Updated register access to single-access
> - Folded keembay_pwm_enable/disable_channel,
>   keembay_pwm_config_period/duty_cycle,
>   and keembay_pwm_config into keembay_pwm_apply
> - Updated error messages/error codes
> - Removed pwm_disable from keembay_pwm_remove
> - Removed clk_prepare/clk_enable/clk_disable from driver
> 
> Lai, Poey Seng (1):
>   pwm: Add PWM driver for Intel Keem Bay
> 
> Vineetha G. Jaya Kumaran (1):
>   dt-bindings: pwm: keembay: Add bindings for Intel Keem Bay PWM
> 
>  .../bindings/pwm/intel,keembay-pwm.yaml       |  47 ++++
>  drivers/pwm/Kconfig                           |   9 +
>  drivers/pwm/Makefile                          |   1 +
>  drivers/pwm/pwm-keembay.c                     | 240 ++++++++++++++++++
>  4 files changed, 297 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pwm/intel,keembay-pwm.yaml
>  create mode 100644 drivers/pwm/pwm-keembay.c

Both patches applied, though I did change the ordering so that
checkpatch doesn't complain about the compatible string not being
defined. I also changed the -ENOSYS error code to -EINVAL for the
unsupported polarity case because checkpatch doesn't like it when
we use -ENOSYS other than for system calls.

I'm also going to follow up with a patch that makes the return value
more consistent for these cases in other drivers.

Thierry

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RE: [PATCH v14 0/2] Add PWM support for Intel Keem Bay SoC

[Ayyathurai, Vijayakannan]

Hi Thierry,
Thanks for reviewing this patch.

> From: Thierry Reding <thierry.reding@gmail.com>
> Sent: Thursday, 12 November, 2020 4:22 AM
> To: Ayyathurai, Vijayakannan <vijayakannan.ayyathurai@intel.com>
> Cc: u.kleine-koenig@pengutronix.de; robh+dt@kernel.org; linux-
> pwm@vger.kernel.org; devicetree@vger.kernel.org; Wan Mohamad, Wan
> Ahmad Zainie <wan.ahmad.zainie.wan.mohamad@intel.com>;
> andriy.shevchenko@linux.intel.com; mgross@linux.intel.com; Raja
> Subramanian, Lakshmi Bai <lakshmi.bai.raja.subramanian@intel.com>
> Subject: Re: [PATCH v14 0/2] Add PWM support for Intel Keem Bay SoC
> 
> On Thu, Oct 22, 2020 at 03:14:45PM +0800,
> vijayakannan.ayyathurai@intel.com wrote:
> > From: Vijayakannan Ayyathurai <vijayakannan.ayyathurai@intel.com>
> >
> > Hi,
> >
> > This patch set enables the support for PWM in the Intel Keem Bay SoC.
> > Keem Bay is an ARM based SoC, and the GPIO module allows
> > configuration of 6 PWM outputs.
> >
> > Patch 1 adds the PWM driver and Patch 2 is for the required
> > Device Tree bindings documentation.
> >
> > This driver was tested on the Keem Bay evaluation module board.
> >
> > Thank you.
> >
> > Regards,
> > Vijay
> >
> > Changes since v13:
> > - Fix indentation error in dt-binding.
> > - Add maintainer name in dt-binding.
> >
> > Changes since v12:
> > - Use devm_add_action_or_reset() as per Andy suggestion.
> > - Do the clk_prepare_enable() after all devm_ stuff as per Uwe suggestion.
> > - Optimize keembay_pwm_remove function.
> > - Simplify the error handling for pwmchip_add.
> > - In Kconfig, Use depends on ARCH_KEEMBAY || (ARM64 &&
> COMPILE_TEST)
> > - Fix indentation error in dt-binding.
> > - Add Uwe's Reviewed-by tag and Vijay's Co-developed-by tag.
> >
> > Changes since v11:
> > - Minor variable name change to match the api needs.
> > - Setup polarity as PWM_POLARITY_NORMAL.
> > - Add comment for LEADIN register usage.
> >
> > Changes since v10:
> > - Update low time calculation formula as per Uwe.
> > - During distruct remove pwmchip first then disable the clock.
> >
> > Changes since v9:
> > - Remove Reported-by tag from the commit log.
> >
> > Changes since v8:
> > - Fix the compilation error reported by kernel test robot.
> > - Add the tag Reported-by: kernel test robot <lkp@intel.com>
> > - Minor correction in the pwm low time calculation formula.
> > - Rebase with 5.9-rc7
> >
> > Changes since v7:
> > - Change the dependency as ARCH_KEEMBAY instead of ARM64 in Kconfig.
> > - Use DIV_ROUND_DOWN_ULL instead of DIV_ROUND_CLOSEST_ULL.
> > - Update the right formula as per Uwe.
> > - List the tags in chronological order.
> > - Add clk_disable_unprepare in the error paths.
> >
> > Changes since v6:
> > - Add reviewed-by tag
> >
> > Changes since v5:
> > - Reorder symbols/Kconfig in drivers/pwm/Kconfig and
> drivers/pwm/Makefile
> > - Use "Limitations" for consistency
> > - Add clk_prepare_enable()
> > - Reorder keembay_pwm_get_state() function call
> > - Rework if conditional for channel disablement in .apply()
> > - Remove channel disabling from .probe(), and clear LEADIN register bits
> >   in .apply instead
> > - Update commit message for Patch 1
> >
> > Changes since v4:
> > - Add co-developed-by tag
> > - Include mod_devicetable.h and remove of.h
> > - Update comment with correct calulation for high/low time
> > - Fix missing return from dev_err_probe
> >
> > Changes since v3:
> > - Removed variable for address and calculate in place instead
> > - Utilized u32_replace_bits() when updating KMB_PWM_LEADIN_OFFSET
> > - Utilized dev_err_probe() for error reporting
> > - Updated comments to use physical units
> > - Updated error check for pwmchip_add()
> >
> > Changes since v2:
> > - Include documentation about HW limitation/behaviour
> > - Use hex values for KMB_PWM_COUNT_MAX
> > - Redefine register macros
> > - Utilize FIELD_GET/FIELD_PREP for calculating pwm_l/h_count and
> >   pwm_count
> > - Round up duty cycle/period values
> > - Get current hardware state in .apply instead of cached values
> > - Do a polarity check before .enabled
> > - Round high time/low time to closest value
> > - Set enable bit in KMB_PWM_LEADIN_OFFSET to 0 in probe
> > - Correct the naming for MODULE_ALIAS
> > - Add additionalProperties: false in DT bindings
> >
> > Changes since v1:
> > - Updated licensing info, "clocks" property and example in DT bindings
> > - Updated name of DT bindings document to match compatible string
> > - Removed 1 patch for addition of new sysfs attribute "count"
> > - Added support for COMPILE_TEST in Kconfig
> > - Updated naming of defines and regmap attribute
> > - Updated calculation of waveform high time and low time
> > - Added range checking for waveform high/low time
> > - Implemented .get_state
> > - Removed register writes for lead-in and count values (left to default)
> > - Updated register access to single-access
> > - Folded keembay_pwm_enable/disable_channel,
> >   keembay_pwm_config_period/duty_cycle,
> >   and keembay_pwm_config into keembay_pwm_apply
> > - Updated error messages/error codes
> > - Removed pwm_disable from keembay_pwm_remove
> > - Removed clk_prepare/clk_enable/clk_disable from driver
> >
> > Lai, Poey Seng (1):
> >   pwm: Add PWM driver for Intel Keem Bay
> >
> > Vineetha G. Jaya Kumaran (1):
> >   dt-bindings: pwm: keembay: Add bindings for Intel Keem Bay PWM
> >
> >  .../bindings/pwm/intel,keembay-pwm.yaml       |  47 ++++
> >  drivers/pwm/Kconfig                           |   9 +
> >  drivers/pwm/Makefile                          |   1 +
> >  drivers/pwm/pwm-keembay.c                     | 240 ++++++++++++++++++
> >  4 files changed, 297 insertions(+)
> >  create mode 100644
> Documentation/devicetree/bindings/pwm/intel,keembay-pwm.yaml
> >  create mode 100644 drivers/pwm/pwm-keembay.c
> 
> Both patches applied, though I did change the ordering so that
> checkpatch doesn't complain about the compatible string not being
> defined. I also changed the -ENOSYS error code to -EINVAL for the
> unsupported polarity case because checkpatch doesn't like it when
> we use -ENOSYS other than for system calls.
> 
> I'm also going to follow up with a patch that makes the return value
> more consistent for these cases in other drivers.

Thank you for your valuable time in fixing that.

> 
> Thierry

Thanks,
Vijay