[PATCH v1 0/2] StarFive's Pulse Width Modulation driver support

[PATCH v1 0/2] StarFive's Pulse Width Modulation driver support

[William Qiu]

Hi,

This patchset adds initial rudimentary support for the StarFive
Pulse Width Modulation controller driver. And this driver will
be used in StarFive's VisionFive 2 board.The first patch add
Documentations for the device and Patch 2 adds device probe for
the module.

The patch series is based on v6.2.

William Qiu (2):
  dt-bindings: PWM: Add StarFive PWM module
  pwm: starfive: Add PWM driver support

 .../devicetree/bindings/pwm/pwm-starfive.yaml |  54 ++++
 MAINTAINERS                                   |   7 +
 drivers/pwm/Kconfig                           |  10 +
 drivers/pwm/Makefile                          |   1 +
 drivers/pwm/pwm-starfive-ptc.c                | 256 ++++++++++++++++++
 5 files changed, 328 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/pwm-starfive.yaml
 create mode 100644 drivers/pwm/pwm-starfive-ptc.c

--
2.34.1

[PATCH v1 1/2] dt-bindings: PWM: Add StarFive PWM module

[William Qiu]

Add documentation to describe StarFive Pulse Width Modulation
controller driver.

Signed-off-by: William Qiu <william.qiu@starfivetech.com>
---
 .../devicetree/bindings/pwm/pwm-starfive.yaml | 54 +++++++++++++++++++
 1 file changed, 54 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/pwm-starfive.yaml

diff --git a/Documentation/devicetree/bindings/pwm/pwm-starfive.yaml b/Documentation/devicetree/bindings/pwm/pwm-starfive.yaml
new file mode 100644
index 000000000000..4ba2a8cc5344
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/pwm-starfive.yaml
@@ -0,0 +1,54 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pwm/pwm-starfive.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: StarFive PWM controller
+
+maintainers:
+  - William Qiu <william.qiu@starfivetech.com>
+
+description:
+  StarFive SoCs contain PWM and when operating in PWM mode, the PTC core generates
+  binary signal with user-programmable low and high periods. Clock source for the
+  PWM can be either system clockor external clock. Each PWM timer block provides 8
+  PWM channels.
+
+allOf:
+  - $ref: pwm.yaml#
+
+properties:
+  compatible:
+    items:
+      - const: starfive,jh7110-pwm
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+  "#pwm-cells":
+    const: 3
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - resets
+
+additionalProperties: false
+
+examples:
+  - |
+    pwm@120d0000 {
+        compatible = "starfive,jh7110-pwm";
+        reg = <0x120d0000 0x10000>;
+        clocks = <&syscrg 121>;
+        resets = <&syscrg 108>;
+        #pwm-cells=<3>;
+    };
-- 
2.34.1

[PATCH v1 2/2] pwm: starfive: Add PWM driver support

[William Qiu]

Add Pulse Width Modulation driver support for StarFive
JH7110 soc.

Signed-off-by: Hal Feng <hal.feng@starfivetech.com>
Signed-off-by: William Qiu <william.qiu@starfivetech.com>
---
 MAINTAINERS                    |   7 +
 drivers/pwm/Kconfig            |  10 ++
 drivers/pwm/Makefile           |   1 +
 drivers/pwm/pwm-starfive-ptc.c | 256 +++++++++++++++++++++++++++++++++
 4 files changed, 274 insertions(+)
 create mode 100644 drivers/pwm/pwm-starfive-ptc.c

diff --git a/MAINTAINERS b/MAINTAINERS
index ac151975d0d3..05b59605d864 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19929,6 +19929,13 @@ F:	drivers/pinctrl/starfive/pinctrl-starfive-jh71*
 F:	include/dt-bindings/pinctrl/pinctrl-starfive-jh7100.h
 F:	include/dt-bindings/pinctrl/starfive,jh7110-pinctrl.h
 
+STARFIVE JH71X0 PWM DRIVERS
+M:	William Qiu <william.qiu@starfivetech.com>
+M:	Hal Feng <hal.feng@starfivetech.com>
+S:	Supported
+F:	Documentation/devicetree/bindings/pwm/pwm-starfive.yaml
+F:	drivers/pwm/pwm-starfive-ptc.c
+
 STARFIVE JH71X0 RESET CONTROLLER DRIVERS
 M:	Emil Renner Berthing <kernel@esmil.dk>
 M:	Hal Feng <hal.feng@starfivetech.com>
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index dae023d783a2..2307a0099994 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -536,6 +536,16 @@ config PWM_SPRD
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-sprd.
 
+config PWM_STARFIVE_PTC
+	tristate "StarFive PWM PTC support"
+	depends on OF
+	depends on COMMON_CLK
+	help
+	  Generic PWM framework driver for StarFive SoCs.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pwm-starfive-ptc.
+
 config PWM_STI
 	tristate "STiH4xx PWM support"
 	depends on ARCH_STI || COMPILE_TEST
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index 7bf1a29f02b8..577f69904baa 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -49,6 +49,7 @@ obj-$(CONFIG_PWM_SIFIVE)	+= pwm-sifive.o
 obj-$(CONFIG_PWM_SL28CPLD)	+= pwm-sl28cpld.o
 obj-$(CONFIG_PWM_SPEAR)		+= pwm-spear.o
 obj-$(CONFIG_PWM_SPRD)		+= pwm-sprd.o
+obj-$(CONFIG_PWM_STARFIVE_PTC)	+= pwm-starfive-ptc.o
 obj-$(CONFIG_PWM_STI)		+= pwm-sti.o
 obj-$(CONFIG_PWM_STM32)		+= pwm-stm32.o
 obj-$(CONFIG_PWM_STM32_LP)	+= pwm-stm32-lp.o
diff --git a/drivers/pwm/pwm-starfive-ptc.c b/drivers/pwm/pwm-starfive-ptc.c
new file mode 100644
index 000000000000..58831c600168
--- /dev/null
+++ b/drivers/pwm/pwm-starfive-ptc.c
@@ -0,0 +1,256 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PWM driver for the StarFive JH7110 SoC
+ *
+ * Copyright (C) 2018 StarFive Technology Co., Ltd.
+ */
+
+#include <dt-bindings/pwm/pwm.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/slab.h>
+#include <linux/clk.h>
+#include <linux/reset.h>
+#include <linux/io.h>
+
+/* how many parameters can be transferred to ptc */
+#define OF_PWM_N_CELLS			3
+
+/* PTC Register offsets */
+#define REG_RPTC_CNTR			0x0
+#define REG_RPTC_HRC			0x4
+#define REG_RPTC_LRC			0x8
+#define REG_RPTC_CTRL			0xC
+
+/* Bit for PWM clock */
+#define BIT_PWM_CLOCK_EN		31
+
+/* Bit for clock gen soft reset */
+#define BIT_CLK_GEN_SOFT_RESET		13
+
+#define NS_PER_SECOND			1000000000
+#define DEFAULT_FREQ_HZ			2000000
+
+/*
+ * Access PTC register (cntr hrc lrc and ctrl),
+ * need to replace PWM_BASE_ADDR
+ */
+#define REG_PTC_BASE_ADDR_SUB(base, N)	\
+((base) + (((N) > 3) ? (((N) % 4) * 0x10 + (1 << 15)) : ((N) * 0x10)))
+#define REG_PTC_RPTC_CNTR(base, N)	(REG_PTC_BASE_ADDR_SUB(base, N))
+#define REG_PTC_RPTC_HRC(base, N)	(REG_PTC_BASE_ADDR_SUB(base, N) + 0x4)
+#define REG_PTC_RPTC_LRC(base, N)	(REG_PTC_BASE_ADDR_SUB(base, N) + 0x8)
+#define REG_PTC_RPTC_CTRL(base, N)	(REG_PTC_BASE_ADDR_SUB(base, N) + 0xC)
+
+/* PTC_RPTC_CTRL */
+#define PTC_EN      BIT(0)
+#define PTC_ECLK    BIT(1)
+#define PTC_NEC     BIT(2)
+#define PTC_OE      BIT(3)
+#define PTC_SIGNLE  BIT(4)
+#define PTC_INTE    BIT(5)
+#define PTC_INT     BIT(6)
+#define PTC_CNTRRST BIT(7)
+#define PTC_CAPTE   BIT(8)
+
+struct starfive_pwm_ptc_device {
+	struct pwm_chip		chip;
+	struct clk		*clk;
+	struct reset_control	*rst;
+	void __iomem		*regs;
+	int			irq;
+	/*pwm apb clock frequency*/
+	unsigned int		approx_freq;
+};
+
+static inline struct starfive_pwm_ptc_device *
+		chip_to_starfive_ptc(struct pwm_chip *c)
+{
+	return container_of(c, struct starfive_pwm_ptc_device, chip);
+}
+
+static int starfive_pwm_ptc_get_state(struct pwm_chip *chip,
+				       struct pwm_device *dev,
+				       struct pwm_state *state)
+{
+	struct starfive_pwm_ptc_device *pwm = chip_to_starfive_ptc(chip);
+	u32 data_lrc, data_hrc;
+	u32 pwm_clk_ns = 0;
+
+	data_lrc = ioread32(REG_PTC_RPTC_LRC(pwm->regs, dev->hwpwm));
+	data_hrc = ioread32(REG_PTC_RPTC_HRC(pwm->regs, dev->hwpwm));
+
+	pwm_clk_ns = NS_PER_SECOND / pwm->approx_freq;
+
+	state->period = data_lrc * pwm_clk_ns;
+	state->duty_cycle = data_hrc * pwm_clk_ns;
+	state->polarity = PWM_POLARITY_NORMAL;
+	state->enabled = 1;
+
+	return 0;
+}
+
+static int starfive_pwm_ptc_apply(struct pwm_chip *chip,
+				  struct pwm_device *dev,
+				  struct pwm_state *state)
+{
+	struct starfive_pwm_ptc_device *pwm = chip_to_starfive_ptc(chip);
+	u32 data_hrc = 0;
+	u32 data_lrc = 0;
+	u32 period_data = 0;
+	u32 duty_data = 0;
+	s64 multi = pwm->approx_freq;
+	s64 div = NS_PER_SECOND;
+	void __iomem *reg_addr;
+
+	if (state->duty_cycle > state->period)
+		state->duty_cycle = state->period;
+
+	while (multi % 10 == 0 && div % 10 == 0 && multi > 0 && div > 0) {
+		multi /= 10;
+		div /= 10;
+	}
+
+	period_data = (u32)(state->period * multi / div);
+	if (abs(period_data * div / multi - state->period)
+	    > abs((period_data + 1) * div / multi - state->period) ||
+	    (state->period > 0 && period_data == 0))
+		period_data += 1;
+
+	if (state->enabled) {
+		duty_data = (u32)(state->duty_cycle * multi / div);
+		if (abs(duty_data * div / multi - state->duty_cycle)
+			> abs((duty_data + 1) * div / multi - state->duty_cycle) ||
+			(state->duty_cycle > 0 && duty_data == 0))
+			duty_data += 1;
+	} else {
+		duty_data = 0;
+	}
+
+	if (state->polarity == PWM_POLARITY_NORMAL)
+		data_hrc = period_data - duty_data;
+	else
+		data_hrc = duty_data;
+
+	data_lrc = period_data;
+
+	reg_addr = REG_PTC_RPTC_HRC(pwm->regs, dev->hwpwm);
+	iowrite32(data_hrc, reg_addr);
+
+	reg_addr = REG_PTC_RPTC_LRC(pwm->regs, dev->hwpwm);
+	iowrite32(data_lrc, reg_addr);
+
+	reg_addr = REG_PTC_RPTC_CNTR(pwm->regs, dev->hwpwm);
+	iowrite32(0, reg_addr);
+
+	reg_addr = REG_PTC_RPTC_CTRL(pwm->regs, dev->hwpwm);
+	iowrite32(PTC_EN | PTC_OE, reg_addr);
+
+	return 0;
+}
+
+static const struct pwm_ops starfive_pwm_ptc_ops = {
+	.get_state	= starfive_pwm_ptc_get_state,
+	.apply		= (void *)starfive_pwm_ptc_apply,
+	.owner		= THIS_MODULE,
+};
+
+static int starfive_pwm_ptc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct starfive_pwm_ptc_device *pwm;
+	struct pwm_chip *chip;
+	struct resource *res;
+	unsigned int clk_apb_freq;
+	int ret;
+
+	pwm = devm_kzalloc(dev, sizeof(*pwm), GFP_KERNEL);
+	if (!pwm)
+		return -ENOMEM;
+
+	chip = &pwm->chip;
+	chip->dev = dev;
+	chip->ops = &starfive_pwm_ptc_ops;
+	chip->npwm = 8;
+
+	chip->of_pwm_n_cells = OF_PWM_N_CELLS;
+	chip->base = -1;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	pwm->regs = devm_ioremap_resource(dev, res);
+	if (IS_ERR(pwm->regs)) {
+		dev_err(dev, "Unable to map IO resources\n");
+		return PTR_ERR(pwm->regs);
+	}
+
+	pwm->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(pwm->clk)) {
+		dev_err(dev, "Unable to get pwm clock\n");
+		return PTR_ERR(pwm->clk);
+	}
+
+	pwm->rst = devm_reset_control_get_exclusive(dev, NULL);
+	if (IS_ERR(pwm->rst)) {
+		dev_err(dev, "Unable to get pwm reset\n");
+		return PTR_ERR(pwm->rst);
+	}
+
+	ret = clk_prepare_enable(pwm->clk);
+	if (ret) {
+		dev_err(dev,
+			"Failed to enable pwm clock, %d\n", ret);
+		return ret;
+	}
+
+	reset_control_deassert(pwm->rst);
+
+	clk_apb_freq = (unsigned int)clk_get_rate(pwm->clk);
+	if (!clk_apb_freq)
+		dev_warn(dev,
+			 "get pwm apb clock rate failed.\n");
+	else
+		pwm->approx_freq = clk_apb_freq;
+
+	ret = pwmchip_add(chip);
+	if (ret < 0) {
+		dev_err(dev, "cannot register PTC: %d\n", ret);
+		clk_disable_unprepare(pwm->clk);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, pwm);
+
+	return 0;
+}
+
+static int starfive_pwm_ptc_remove(struct platform_device *dev)
+{
+	struct starfive_pwm_ptc_device *pwm = platform_get_drvdata(dev);
+	struct pwm_chip *chip = &pwm->chip;
+
+	pwmchip_remove(chip);
+
+	return 0;
+}
+
+static const struct of_device_id starfive_pwm_ptc_of_match[] = {
+	{ .compatible = "starfive,jh7110-pwm" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, starfive_pwm_ptc_of_match);
+
+static struct platform_driver starfive_pwm_ptc_driver = {
+	.probe = starfive_pwm_ptc_probe,
+	.remove = starfive_pwm_ptc_remove,
+	.driver = {
+		.name = "pwm-starfive-ptc",
+		.of_match_table = of_match_ptr(starfive_pwm_ptc_of_match),
+	},
+};
+module_platform_driver(starfive_pwm_ptc_driver);
+
+MODULE_AUTHOR("Jenny Zhang <jenny.zhang@starfivetech.com>");
+MODULE_AUTHOR("Hal Feng <hal.feng@starfivetech.com>");
+MODULE_DESCRIPTION("StarFive PWM PTC driver");
+MODULE_LICENSE("GPL");
-- 
2.34.1

Re: [PATCH v1 1/2] dt-bindings: PWM: Add StarFive PWM module

[Krzysztof Kozlowski]

On 28/02/2023 10:13, William Qiu wrote:
> Add documentation to describe StarFive Pulse Width Modulation
> controller driver.
> 
> Signed-off-by: William Qiu <william.qiu@starfivetech.com>
> ---
>  .../devicetree/bindings/pwm/pwm-starfive.yaml | 54 +++++++++++++++++++
>  1 file changed, 54 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pwm/pwm-starfive.yaml
> 
> diff --git a/Documentation/devicetree/bindings/pwm/pwm-starfive.yaml b/Documentation/devicetree/bindings/pwm/pwm-starfive.yaml
> new file mode 100644
> index 000000000000..4ba2a8cc5344
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pwm/pwm-starfive.yaml

Filename based on compatible, so starfive,jh7110-pwm.yaml

> @@ -0,0 +1,54 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/pwm/pwm-starfive.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: StarFive PWM controller
> +
> +maintainers:
> +  - William Qiu <william.qiu@starfivetech.com>
> +
> +description:
> +  StarFive SoCs contain PWM and when operating in PWM mode, the PTC core generates
> +  binary signal with user-programmable low and high periods. Clock source for the
> +  PWM can be either system clockor external clock. Each PWM timer block provides 8
> +  PWM channels.
> +
> +allOf:
> +  - $ref: pwm.yaml#
> +
> +properties:
> +  compatible:
> +    items:

Drop items, not a list in your case.

> +      - const: starfive,jh7110-pwm
> +


Best regards,
Krzysztof

Re: [PATCH v1 2/2] pwm: starfive: Add PWM driver support

[Krzysztof Kozlowski]

On 28/02/2023 10:13, William Qiu wrote:
> Add Pulse Width Modulation driver support for StarFive
> JH7110 soc.
> 
> Signed-off-by: Hal Feng <hal.feng@starfivetech.com>
> Signed-off-by: William Qiu <william.qiu@starfivetech.com>
> ---
>  MAINTAINERS                    |   7 +
>  drivers/pwm/Kconfig            |  10 ++
>  drivers/pwm/Makefile           |   1 +
>  drivers/pwm/pwm-starfive-ptc.c | 256 +++++++++++++++++++++++++++++++++
>  4 files changed, 274 insertions(+)
>  create mode 100644 drivers/pwm/pwm-starfive-ptc.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index ac151975d0d3..05b59605d864 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -19929,6 +19929,13 @@ F:	drivers/pinctrl/starfive/pinctrl-starfive-jh71*
>  F:	include/dt-bindings/pinctrl/pinctrl-starfive-jh7100.h
>  F:	include/dt-bindings/pinctrl/starfive,jh7110-pinctrl.h
>  
> +STARFIVE JH71X0 PWM DRIVERS
> +M:	William Qiu <william.qiu@starfivetech.com>
> +M:	Hal Feng <hal.feng@starfivetech.com>
> +S:	Supported
> +F:	Documentation/devicetree/bindings/pwm/pwm-starfive.yaml
> +F:	drivers/pwm/pwm-starfive-ptc.c
> +
>  STARFIVE JH71X0 RESET CONTROLLER DRIVERS
>  M:	Emil Renner Berthing <kernel@esmil.dk>
>  M:	Hal Feng <hal.feng@starfivetech.com>
> diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
> index dae023d783a2..2307a0099994 100644
> --- a/drivers/pwm/Kconfig
> +++ b/drivers/pwm/Kconfig
> @@ -536,6 +536,16 @@ config PWM_SPRD
>  	  To compile this driver as a module, choose M here: the module
>  	  will be called pwm-sprd.
>  
> +config PWM_STARFIVE_PTC
> +	tristate "StarFive PWM PTC support"
> +	depends on OF
> +	depends on COMMON_CLK
> +	help
> +	  Generic PWM framework driver for StarFive SoCs.
> +
> +	  To compile this driver as a module, choose M here: the module
> +	  will be called pwm-starfive-ptc.
> +
>  config PWM_STI
>  	tristate "STiH4xx PWM support"
>  	depends on ARCH_STI || COMPILE_TEST
> diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
> index 7bf1a29f02b8..577f69904baa 100644
> --- a/drivers/pwm/Makefile
> +++ b/drivers/pwm/Makefile
> @@ -49,6 +49,7 @@ obj-$(CONFIG_PWM_SIFIVE)	+= pwm-sifive.o
>  obj-$(CONFIG_PWM_SL28CPLD)	+= pwm-sl28cpld.o
>  obj-$(CONFIG_PWM_SPEAR)		+= pwm-spear.o
>  obj-$(CONFIG_PWM_SPRD)		+= pwm-sprd.o
> +obj-$(CONFIG_PWM_STARFIVE_PTC)	+= pwm-starfive-ptc.o
>  obj-$(CONFIG_PWM_STI)		+= pwm-sti.o
>  obj-$(CONFIG_PWM_STM32)		+= pwm-stm32.o
>  obj-$(CONFIG_PWM_STM32_LP)	+= pwm-stm32-lp.o
> diff --git a/drivers/pwm/pwm-starfive-ptc.c b/drivers/pwm/pwm-starfive-ptc.c
> new file mode 100644
> index 000000000000..58831c600168
> --- /dev/null
> +++ b/drivers/pwm/pwm-starfive-ptc.c
> @@ -0,0 +1,256 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * PWM driver for the StarFive JH7110 SoC
> + *
> + * Copyright (C) 2018 StarFive Technology Co., Ltd.
> + */
> +
> +#include <dt-bindings/pwm/pwm.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/pwm.h>
> +#include <linux/slab.h>
> +#include <linux/clk.h>
> +#include <linux/reset.h>
> +#include <linux/io.h>
> +
> +/* how many parameters can be transferred to ptc */
> +#define OF_PWM_N_CELLS			3
> +
> +/* PTC Register offsets */
> +#define REG_RPTC_CNTR			0x0
> +#define REG_RPTC_HRC			0x4
> +#define REG_RPTC_LRC			0x8
> +#define REG_RPTC_CTRL			0xC
> +
> +/* Bit for PWM clock */
> +#define BIT_PWM_CLOCK_EN		31
> +
> +/* Bit for clock gen soft reset */
> +#define BIT_CLK_GEN_SOFT_RESET		13
> +
> +#define NS_PER_SECOND			1000000000
> +#define DEFAULT_FREQ_HZ			2000000

Drop unused defines.

> +
> +/*
> + * Access PTC register (cntr hrc lrc and ctrl),
> + * need to replace PWM_BASE_ADDR
> + */
> +#define REG_PTC_BASE_ADDR_SUB(base, N)	\
> +((base) + (((N) > 3) ? (((N) % 4) * 0x10 + (1 << 15)) : ((N) * 0x10)))
> +#define REG_PTC_RPTC_CNTR(base, N)	(REG_PTC_BASE_ADDR_SUB(base, N))
> +#define REG_PTC_RPTC_HRC(base, N)	(REG_PTC_BASE_ADDR_SUB(base, N) + 0x4)
> +#define REG_PTC_RPTC_LRC(base, N)	(REG_PTC_BASE_ADDR_SUB(base, N) + 0x8)
> +#define REG_PTC_RPTC_CTRL(base, N)	(REG_PTC_BASE_ADDR_SUB(base, N) + 0xC)
> +
> +/* PTC_RPTC_CTRL */
> +#define PTC_EN      BIT(0)
> +#define PTC_ECLK    BIT(1)
> +#define PTC_NEC     BIT(2)
> +#define PTC_OE      BIT(3)
> +#define PTC_SIGNLE  BIT(4)
> +#define PTC_INTE    BIT(5)
> +#define PTC_INT     BIT(6)
> +#define PTC_CNTRRST BIT(7)
> +#define PTC_CAPTE   BIT(8)
> +
> +struct starfive_pwm_ptc_device {
> +	struct pwm_chip		chip;
> +	struct clk		*clk;
> +	struct reset_control	*rst;
> +	void __iomem		*regs;
> +	int			irq;
> +	/*pwm apb clock frequency*/

Missing spaces. Use Linux coding style.

> +	unsigned int		approx_freq;
> +};
> +
> +static inline struct starfive_pwm_ptc_device *
> +		chip_to_starfive_ptc(struct pwm_chip *c)
> +{
> +	return container_of(c, struct starfive_pwm_ptc_device, chip);
> +}
> +

(...)

> +static int starfive_pwm_ptc_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct starfive_pwm_ptc_device *pwm;
> +	struct pwm_chip *chip;
> +	struct resource *res;
> +	unsigned int clk_apb_freq;
> +	int ret;
> +
> +	pwm = devm_kzalloc(dev, sizeof(*pwm), GFP_KERNEL);
> +	if (!pwm)
> +		return -ENOMEM;
> +
> +	chip = &pwm->chip;
> +	chip->dev = dev;
> +	chip->ops = &starfive_pwm_ptc_ops;
> +	chip->npwm = 8;
> +
> +	chip->of_pwm_n_cells = OF_PWM_N_CELLS;
> +	chip->base = -1;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	pwm->regs = devm_ioremap_resource(dev, res);

Combine these two, there is a helper for it.

> +	if (IS_ERR(pwm->regs)) {
> +		dev_err(dev, "Unable to map IO resources\n");

return dev_err_probe(), everywhere probably.

> +		return PTR_ERR(pwm->regs);
> +	}
> +
> +	pwm->clk = devm_clk_get(dev, NULL);
> +	if (IS_ERR(pwm->clk)) {
> +		dev_err(dev, "Unable to get pwm clock\n");
> +		return PTR_ERR(pwm->clk);
> +	}
> +
> +	pwm->rst = devm_reset_control_get_exclusive(dev, NULL);
> +	if (IS_ERR(pwm->rst)) {
> +		dev_err(dev, "Unable to get pwm reset\n");
> +		return PTR_ERR(pwm->rst);
> +	}
> +
> +	ret = clk_prepare_enable(pwm->clk);
> +	if (ret) {
> +		dev_err(dev,
> +			"Failed to enable pwm clock, %d\n", ret);
> +		return ret;
> +	}
> +
> +	reset_control_deassert(pwm->rst);
> +
> +	clk_apb_freq = (unsigned int)clk_get_rate(pwm->clk);

Why do you need this local variable? And why the cast?

> +	if (!clk_apb_freq)
> +		dev_warn(dev,
> +			 "get pwm apb clock rate failed.\n");

and pwm->approx_freq stays 0 which you later use for dividing. Did you
actually test it? It should produce big splat...

> +	else
> +		pwm->approx_freq = clk_apb_freq;
> +
> +	ret = pwmchip_add(chip);

devm

> +	if (ret < 0) {
> +		dev_err(dev, "cannot register PTC: %d\n", ret);
> +		clk_disable_unprepare(pwm->clk);
> +		return ret;
> +	}
> +
> +	platform_set_drvdata(pdev, pwm);
> +
> +	return 0;
> +}
> +
> +static int starfive_pwm_ptc_remove(struct platform_device *dev)
> +{
> +	struct starfive_pwm_ptc_device *pwm = platform_get_drvdata(dev);
> +	struct pwm_chip *chip = &pwm->chip;
> +
> +	pwmchip_remove(chip);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id starfive_pwm_ptc_of_match[] = {
> +	{ .compatible = "starfive,jh7110-pwm" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, starfive_pwm_ptc_of_match);
> +
> +static struct platform_driver starfive_pwm_ptc_driver = {
> +	.probe = starfive_pwm_ptc_probe,
> +	.remove = starfive_pwm_ptc_remove,
> +	.driver = {
> +		.name = "pwm-starfive-ptc",
> +		.of_match_table = of_match_ptr(starfive_pwm_ptc_of_match),

of_match_ptr goes with maybe_unused, which you do not have. Anyway I am
not sure what's the benefit of having it here, so just drop it.

Best regards,
Krzysztof

Re: [PATCH v1 1/2] dt-bindings: PWM: Add StarFive PWM module

[William Qiu]

On 2023/2/28 22:07, Krzysztof Kozlowski wrote:
> On 28/02/2023 10:13, William Qiu wrote:
>> Add documentation to describe StarFive Pulse Width Modulation
>> controller driver.
>> 
>> Signed-off-by: William Qiu <william.qiu@starfivetech.com>
>> ---
>>  .../devicetree/bindings/pwm/pwm-starfive.yaml | 54 +++++++++++++++++++
>>  1 file changed, 54 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/pwm/pwm-starfive.yaml
>> 
>> diff --git a/Documentation/devicetree/bindings/pwm/pwm-starfive.yaml b/Documentation/devicetree/bindings/pwm/pwm-starfive.yaml
>> new file mode 100644
>> index 000000000000..4ba2a8cc5344
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/pwm/pwm-starfive.yaml
> 
> Filename based on compatible, so starfive,jh7110-pwm.yaml
> 
>> @@ -0,0 +1,54 @@
>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/pwm/pwm-starfive.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: StarFive PWM controller
>> +
>> +maintainers:
>> +  - William Qiu <william.qiu@starfivetech.com>
>> +
>> +description:
>> +  StarFive SoCs contain PWM and when operating in PWM mode, the PTC core generates
>> +  binary signal with user-programmable low and high periods. Clock source for the
>> +  PWM can be either system clockor external clock. Each PWM timer block provides 8
>> +  PWM channels.
>> +
>> +allOf:
>> +  - $ref: pwm.yaml#
>> +
>> +properties:
>> +  compatible:
>> +    items:
> 
> Drop items, not a list in your case.
> 

Will drop. Thanks for taking time reviewing this patch series.

Best regards
William
>> +      - const: starfive,jh7110-pwm
>> +
> 
> 
> Best regards,
> Krzysztof
> 

Re: [PATCH v1 2/2] pwm: starfive: Add PWM driver support

[William Qiu]

On 2023/2/28 22:34, Krzysztof Kozlowski wrote:
> On 28/02/2023 10:13, William Qiu wrote:
>> Add Pulse Width Modulation driver support for StarFive
>> JH7110 soc.
>> 
>> Signed-off-by: Hal Feng <hal.feng@starfivetech.com>
>> Signed-off-by: William Qiu <william.qiu@starfivetech.com>
>> ---
>>  MAINTAINERS                    |   7 +
>>  drivers/pwm/Kconfig            |  10 ++
>>  drivers/pwm/Makefile           |   1 +
>>  drivers/pwm/pwm-starfive-ptc.c | 256 +++++++++++++++++++++++++++++++++
>>  4 files changed, 274 insertions(+)
>>  create mode 100644 drivers/pwm/pwm-starfive-ptc.c
>> 
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index ac151975d0d3..05b59605d864 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -19929,6 +19929,13 @@ F:	drivers/pinctrl/starfive/pinctrl-starfive-jh71*
>>  F:	include/dt-bindings/pinctrl/pinctrl-starfive-jh7100.h
>>  F:	include/dt-bindings/pinctrl/starfive,jh7110-pinctrl.h
>>  
>> +STARFIVE JH71X0 PWM DRIVERS
>> +M:	William Qiu <william.qiu@starfivetech.com>
>> +M:	Hal Feng <hal.feng@starfivetech.com>
>> +S:	Supported
>> +F:	Documentation/devicetree/bindings/pwm/pwm-starfive.yaml
>> +F:	drivers/pwm/pwm-starfive-ptc.c
>> +
>>  STARFIVE JH71X0 RESET CONTROLLER DRIVERS
>>  M:	Emil Renner Berthing <kernel@esmil.dk>
>>  M:	Hal Feng <hal.feng@starfivetech.com>
>> diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
>> index dae023d783a2..2307a0099994 100644
>> --- a/drivers/pwm/Kconfig
>> +++ b/drivers/pwm/Kconfig
>> @@ -536,6 +536,16 @@ config PWM_SPRD
>>  	  To compile this driver as a module, choose M here: the module
>>  	  will be called pwm-sprd.
>>  
>> +config PWM_STARFIVE_PTC
>> +	tristate "StarFive PWM PTC support"
>> +	depends on OF
>> +	depends on COMMON_CLK
>> +	help
>> +	  Generic PWM framework driver for StarFive SoCs.
>> +
>> +	  To compile this driver as a module, choose M here: the module
>> +	  will be called pwm-starfive-ptc.
>> +
>>  config PWM_STI
>>  	tristate "STiH4xx PWM support"
>>  	depends on ARCH_STI || COMPILE_TEST
>> diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
>> index 7bf1a29f02b8..577f69904baa 100644
>> --- a/drivers/pwm/Makefile
>> +++ b/drivers/pwm/Makefile
>> @@ -49,6 +49,7 @@ obj-$(CONFIG_PWM_SIFIVE)	+= pwm-sifive.o
>>  obj-$(CONFIG_PWM_SL28CPLD)	+= pwm-sl28cpld.o
>>  obj-$(CONFIG_PWM_SPEAR)		+= pwm-spear.o
>>  obj-$(CONFIG_PWM_SPRD)		+= pwm-sprd.o
>> +obj-$(CONFIG_PWM_STARFIVE_PTC)	+= pwm-starfive-ptc.o
>>  obj-$(CONFIG_PWM_STI)		+= pwm-sti.o
>>  obj-$(CONFIG_PWM_STM32)		+= pwm-stm32.o
>>  obj-$(CONFIG_PWM_STM32_LP)	+= pwm-stm32-lp.o
>> diff --git a/drivers/pwm/pwm-starfive-ptc.c b/drivers/pwm/pwm-starfive-ptc.c
>> new file mode 100644
>> index 000000000000..58831c600168
>> --- /dev/null
>> +++ b/drivers/pwm/pwm-starfive-ptc.c
>> @@ -0,0 +1,256 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * PWM driver for the StarFive JH7110 SoC
>> + *
>> + * Copyright (C) 2018 StarFive Technology Co., Ltd.
>> + */
>> +
>> +#include <dt-bindings/pwm/pwm.h>
>> +#include <linux/module.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/pwm.h>
>> +#include <linux/slab.h>
>> +#include <linux/clk.h>
>> +#include <linux/reset.h>
>> +#include <linux/io.h>
>> +
>> +/* how many parameters can be transferred to ptc */
>> +#define OF_PWM_N_CELLS			3
>> +
>> +/* PTC Register offsets */
>> +#define REG_RPTC_CNTR			0x0
>> +#define REG_RPTC_HRC			0x4
>> +#define REG_RPTC_LRC			0x8
>> +#define REG_RPTC_CTRL			0xC
>> +
>> +/* Bit for PWM clock */
>> +#define BIT_PWM_CLOCK_EN		31
>> +
>> +/* Bit for clock gen soft reset */
>> +#define BIT_CLK_GEN_SOFT_RESET		13
>> +
>> +#define NS_PER_SECOND			1000000000
>> +#define DEFAULT_FREQ_HZ			2000000
> 
> Drop unused defines.
> 
Will drop.
>> +
>> +/*
>> + * Access PTC register (cntr hrc lrc and ctrl),
>> + * need to replace PWM_BASE_ADDR
>> + */
>> +#define REG_PTC_BASE_ADDR_SUB(base, N)	\
>> +((base) + (((N) > 3) ? (((N) % 4) * 0x10 + (1 << 15)) : ((N) * 0x10)))
>> +#define REG_PTC_RPTC_CNTR(base, N)	(REG_PTC_BASE_ADDR_SUB(base, N))
>> +#define REG_PTC_RPTC_HRC(base, N)	(REG_PTC_BASE_ADDR_SUB(base, N) + 0x4)
>> +#define REG_PTC_RPTC_LRC(base, N)	(REG_PTC_BASE_ADDR_SUB(base, N) + 0x8)
>> +#define REG_PTC_RPTC_CTRL(base, N)	(REG_PTC_BASE_ADDR_SUB(base, N) + 0xC)
>> +
>> +/* PTC_RPTC_CTRL */
>> +#define PTC_EN      BIT(0)
>> +#define PTC_ECLK    BIT(1)
>> +#define PTC_NEC     BIT(2)
>> +#define PTC_OE      BIT(3)
>> +#define PTC_SIGNLE  BIT(4)
>> +#define PTC_INTE    BIT(5)
>> +#define PTC_INT     BIT(6)
>> +#define PTC_CNTRRST BIT(7)
>> +#define PTC_CAPTE   BIT(8)
>> +
>> +struct starfive_pwm_ptc_device {
>> +	struct pwm_chip		chip;
>> +	struct clk		*clk;
>> +	struct reset_control	*rst;
>> +	void __iomem		*regs;
>> +	int			irq;
>> +	/*pwm apb clock frequency*/
> 
> Missing spaces. Use Linux coding style.
> 
Will fix.
>> +	unsigned int		approx_freq;
>> +};
>> +
>> +static inline struct starfive_pwm_ptc_device *
>> +		chip_to_starfive_ptc(struct pwm_chip *c)
>> +{
>> +	return container_of(c, struct starfive_pwm_ptc_device, chip);
>> +}
>> +
> 
> (...)
> 
>> +static int starfive_pwm_ptc_probe(struct platform_device *pdev)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	struct starfive_pwm_ptc_device *pwm;
>> +	struct pwm_chip *chip;
>> +	struct resource *res;
>> +	unsigned int clk_apb_freq;
>> +	int ret;
>> +
>> +	pwm = devm_kzalloc(dev, sizeof(*pwm), GFP_KERNEL);
>> +	if (!pwm)
>> +		return -ENOMEM;
>> +
>> +	chip = &pwm->chip;
>> +	chip->dev = dev;
>> +	chip->ops = &starfive_pwm_ptc_ops;
>> +	chip->npwm = 8;
>> +
>> +	chip->of_pwm_n_cells = OF_PWM_N_CELLS;
>> +	chip->base = -1;
>> +
>> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +	pwm->regs = devm_ioremap_resource(dev, res);
> 
> Combine these two, there is a helper for it.
> 
Will update.
>> +	if (IS_ERR(pwm->regs)) {
>> +		dev_err(dev, "Unable to map IO resources\n");
> 
> return dev_err_probe(), everywhere probably.
> 
Will fix.
>> +		return PTR_ERR(pwm->regs);
>> +	}
>> +
>> +	pwm->clk = devm_clk_get(dev, NULL);
>> +	if (IS_ERR(pwm->clk)) {
>> +		dev_err(dev, "Unable to get pwm clock\n");
>> +		return PTR_ERR(pwm->clk);
>> +	}
>> +
>> +	pwm->rst = devm_reset_control_get_exclusive(dev, NULL);
>> +	if (IS_ERR(pwm->rst)) {
>> +		dev_err(dev, "Unable to get pwm reset\n");
>> +		return PTR_ERR(pwm->rst);
>> +	}
>> +
>> +	ret = clk_prepare_enable(pwm->clk);
>> +	if (ret) {
>> +		dev_err(dev,
>> +			"Failed to enable pwm clock, %d\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	reset_control_deassert(pwm->rst);
>> +
>> +	clk_apb_freq = (unsigned int)clk_get_rate(pwm->clk);
> 
> Why do you need this local variable? And why the cast?
> 
Will drop this local variable.
>> +	if (!clk_apb_freq)
>> +		dev_warn(dev,
>> +			 "get pwm apb clock rate failed.\n");
> 
> and pwm->approx_freq stays 0 which you later use for dividing. Did you
> actually test it? It should produce big splat...
> 
Will update.
>> +	else
>> +		pwm->approx_freq = clk_apb_freq;
>> +
>> +	ret = pwmchip_add(chip);
> 
> devm
> 
Will update.
>> +	if (ret < 0) {
>> +		dev_err(dev, "cannot register PTC: %d\n", ret);
>> +		clk_disable_unprepare(pwm->clk);
>> +		return ret;
>> +	}
>> +
>> +	platform_set_drvdata(pdev, pwm);
>> +
>> +	return 0;
>> +}
>> +
>> +static int starfive_pwm_ptc_remove(struct platform_device *dev)
>> +{
>> +	struct starfive_pwm_ptc_device *pwm = platform_get_drvdata(dev);
>> +	struct pwm_chip *chip = &pwm->chip;
>> +
>> +	pwmchip_remove(chip);
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct of_device_id starfive_pwm_ptc_of_match[] = {
>> +	{ .compatible = "starfive,jh7110-pwm" },
>> +	{},
>> +};
>> +MODULE_DEVICE_TABLE(of, starfive_pwm_ptc_of_match);
>> +
>> +static struct platform_driver starfive_pwm_ptc_driver = {
>> +	.probe = starfive_pwm_ptc_probe,
>> +	.remove = starfive_pwm_ptc_remove,
>> +	.driver = {
>> +		.name = "pwm-starfive-ptc",
>> +		.of_match_table = of_match_ptr(starfive_pwm_ptc_of_match),
> 
> of_match_ptr goes with maybe_unused, which you do not have. Anyway I am
> not sure what's the benefit of having it here, so just drop it.
> 
Will drop.
Thank you for spending time reviewing and providing helpful comments
for this driver

Best regards
William
> Best regards,
> Krzysztof
> 

Re: [PATCH v1 0/2] StarFive's Pulse Width Modulation driver support

[Conor Dooley]

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Hey William,

On Tue, Feb 28, 2023 at 05:13:43PM +0800, William Qiu wrote:
> Hi,
> 
> This patchset adds initial rudimentary support for the StarFive
> Pulse Width Modulation controller driver. And this driver will
> be used in StarFive's VisionFive 2 board.The first patch add
> Documentations for the device and Patch 2 adds device probe for
> the module.
> 
> The patch series is based on v6.2.
> 
> William Qiu (2):
>   dt-bindings: PWM: Add StarFive PWM module
>   pwm: starfive: Add PWM driver support

Is there a corresponding dts addition for this driver?

Cheers,
Conor.


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Re: [PATCH v1 0/2] StarFive's Pulse Width Modulation driver support

[William Qiu]

On 2023/3/1 16:10, Conor Dooley wrote:
> Hey William,
> 
> On Tue, Feb 28, 2023 at 05:13:43PM +0800, William Qiu wrote:
>> Hi,
>> 
>> This patchset adds initial rudimentary support for the StarFive
>> Pulse Width Modulation controller driver. And this driver will
>> be used in StarFive's VisionFive 2 board.The first patch add
>> Documentations for the device and Patch 2 adds device probe for
>> the module.
>> 
>> The patch series is based on v6.2.
>> 
>> William Qiu (2):
>>   dt-bindings: PWM: Add StarFive PWM module
>>   pwm: starfive: Add PWM driver support
> 
> Is there a corresponding dts addition for this driver?
> 
> Cheers,
> Conor
Hi Conor,

There is, but after communicating with Hal Feng, I decided to upload
bindings and driver based on mainline first, and then upload dts after
Hal Feng's minimal system is merged.

Best Regards
William