2023-02-28 09:15:27

by William Qiu

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

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



2023-02-28 09:15:31

by William Qiu

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

Add Pulse Width Modulation driver support for StarFive
JH7110 soc.

Signed-off-by: Hal Feng <[email protected]>
Signed-off-by: William Qiu <[email protected]>
---
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 <[email protected]>
+M: Hal Feng <[email protected]>
+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 <[email protected]>
M: Hal Feng <[email protected]>
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 <[email protected]>");
+MODULE_AUTHOR("Hal Feng <[email protected]>");
+MODULE_DESCRIPTION("StarFive PWM PTC driver");
+MODULE_LICENSE("GPL");
--
2.34.1


2023-02-28 14:35:04

by Krzysztof Kozlowski

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

On 28/02/2023 10:13, William Qiu wrote:
> Add Pulse Width Modulation driver support for StarFive
> JH7110 soc.
>
> Signed-off-by: Hal Feng <[email protected]>
> Signed-off-by: William Qiu <[email protected]>
> ---
> 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 <[email protected]>
> +M: Hal Feng <[email protected]>
> +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 <[email protected]>
> M: Hal Feng <[email protected]>
> 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


2023-03-01 06:18:20

by William Qiu

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



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 <[email protected]>
>> Signed-off-by: William Qiu <[email protected]>
>> ---
>> 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 <[email protected]>
>> +M: Hal Feng <[email protected]>
>> +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 <[email protected]>
>> M: Hal Feng <[email protected]>
>> 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
>

2023-03-01 08:10:47

by Conor Dooley

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

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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2023-03-01 08:17:50

by William Qiu

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



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