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[v2,2/2] pwm: sophgo: add pwm support for Sophgo CV1800 SoC

Message ID 20240212121729.1086718-3-qiujingbao.dlmu@gmail.com
State Changes Requested
Headers show
Series riscv: pwm: sophgo: add pwm support for CV1800 | expand

Commit Message

Jingbao Qiu Feb. 12, 2024, 12:17 p.m. UTC
Implement the PWM driver for CV1800.

Signed-off-by: Jingbao Qiu <qiujingbao.dlmu@gmail.com>
---
 drivers/pwm/Kconfig      |  10 ++
 drivers/pwm/Makefile     |   1 +
 drivers/pwm/pwm-cv1800.c | 248 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 259 insertions(+)
 create mode 100644 drivers/pwm/pwm-cv1800.c

Comments

Jingbao Qiu Feb. 20, 2024, 8:50 a.m. UTC | #1
Hi Uwe,

Gentle ping. Could you share some comments on this patch?

Best regards,
Jingbao Qiu

On Mon, Feb 12, 2024 at 8:17 PM Jingbao Qiu <qiujingbao.dlmu@gmail.com> wrote:
>
> Implement the PWM driver for CV1800.
>
> Signed-off-by: Jingbao Qiu <qiujingbao.dlmu@gmail.com>
> ---
>  drivers/pwm/Kconfig      |  10 ++
>  drivers/pwm/Makefile     |   1 +
>  drivers/pwm/pwm-cv1800.c | 248 +++++++++++++++++++++++++++++++++++++++
>  3 files changed, 259 insertions(+)
>  create mode 100644 drivers/pwm/pwm-cv1800.c
>
> diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
> index 4b956d661755..455f07af94f7 100644
> --- a/drivers/pwm/Kconfig
> +++ b/drivers/pwm/Kconfig
> @@ -186,6 +186,16 @@ config PWM_CROS_EC
>           PWM driver for exposing a PWM attached to the ChromeOS Embedded
>           Controller.
>
> +config PWM_CV1800
> +       tristate "Sophgo CV1800 PWM driver"
> +       depends on ARCH_SOPHGO || COMPILE_TEST
> +       help
> +         Generic PWM framework driver for the Sophgo CV1800 series
> +         SoCs.
> +
> +         To compile this driver as a module, build the dependecies
> +         as modules, this will be called pwm-cv1800.
> +
>  config PWM_DWC_CORE
>         tristate
>         depends on HAS_IOMEM
> diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
> index c5ec9e168ee7..6c3c4a07a316 100644
> --- a/drivers/pwm/Makefile
> +++ b/drivers/pwm/Makefile
> @@ -15,6 +15,7 @@ obj-$(CONFIG_PWM_CLK)         += pwm-clk.o
>  obj-$(CONFIG_PWM_CLPS711X)     += pwm-clps711x.o
>  obj-$(CONFIG_PWM_CRC)          += pwm-crc.o
>  obj-$(CONFIG_PWM_CROS_EC)      += pwm-cros-ec.o
> +obj-$(CONFIG_PWM_CV1800)       += pwm-cv1800.o
>  obj-$(CONFIG_PWM_DWC_CORE)     += pwm-dwc-core.o
>  obj-$(CONFIG_PWM_DWC)          += pwm-dwc.o
>  obj-$(CONFIG_PWM_EP93XX)       += pwm-ep93xx.o
> diff --git a/drivers/pwm/pwm-cv1800.c b/drivers/pwm/pwm-cv1800.c
> new file mode 100644
> index 000000000000..3d7f2ff3a6c2
> --- /dev/null
> +++ b/drivers/pwm/pwm-cv1800.c
> @@ -0,0 +1,248 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * pwm-cv1800.c: PWM driver for Sophgo cv1800
> + *
> + * Author: Jingbao Qiu <qiujingbao.dlmu@gmail.com>
> + *
> + * Limitations:
> + * - It output low when PWM channel disabled.
> + * - This pwm device supports dynamic loading of PWM parameters. When PWMSTART
> + *   is written from 0 to 1, the register value (HLPERIODn, PERIODn) will be
> + *   temporarily stored inside the PWM. If you want to dynamically change the
> + *   waveform during PWM output, after writing the new value to HLPERIODn and
> + *   PERIODn, write 1 and then 0 to PWMUPDATE[n] to make the new value effective.
> + * - Supports up to Rate/2 output, and the lowest is about Rate/(2^30-1).
> + * - By setting HLPERIODn to 0, can produce 100% duty cycle.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/pwm.h>
> +#include <linux/regmap.h>
> +
> +#define PWM_CV1800_HLPERIOD_BASE       0x00
> +#define PWM_CV1800_PERIOD_BASE         0x04
> +#define PWM_CV1800_PWM_CV1800_POLARITY 0x40
> +#define PWM_CV1800_START               0x44
> +#define PWM_CV1800_DONE                0x48
> +#define PWM_CV1800_UPDATE              0x4c
> +#define PWM_CV1800_OE                  0xd0
> +#define PWM_CV1800_HLPERIOD_SHIFT      0x08
> +#define PWM_CV1800_PERIOD_SHIFT        0x08
> +
> +#define PWM_CV1800_HLPERIOD(n)         \
> +       (PWM_CV1800_HLPERIOD_BASE + ((n) * PWM_CV1800_HLPERIOD_SHIFT))
> +#define PWM_CV1800_PERIOD(n)           \
> +       (PWM_CV1800_PERIOD_BASE + ((n) * PWM_CV1800_PERIOD_SHIFT))
> +
> +#define PWM_CV1800_UPDATE_MASK(n) (BIT(0) << (n))
> +#define PWM_CV1800_OE_MASK(n)     (BIT(0) << (n))
> +#define PWM_CV1800_START_MASK(n)  (BIT(0) << (n))
> +
> +#define PWM_CV1800_MAXPERIOD      (BIT(30) - 1)
> +#define PWM_CV1800_MINPERIOD      BIT(1)
> +#define PWM_CV1800_MINHLPERIOD    BIT(0)
> +#define PWM_CV1800_PERIOD_RESET   BIT(1)
> +#define PWM_CV1800_HLPERIOD_RESET BIT(0)
> +#define PWM_CV1800_REG_DISABLE    0x0U
> +#define PWM_CV1800_REG_ENABLE(n)  (BIT(0) << (n))
> +
> +struct cv1800_pwm {
> +       struct pwm_chip chip;
> +       struct regmap *map;
> +       struct clk *clk;
> +       unsigned long clk_rate;
> +};
> +
> +static const struct regmap_config cv1800_pwm_regmap_config = {
> +       .reg_bits = 32,
> +       .val_bits = 32,
> +       .reg_stride = 4,
> +};
> +
> +static inline struct cv1800_pwm *to_cv1800_pwm_dev(struct pwm_chip *chip)
> +{
> +       return container_of(chip, struct cv1800_pwm, chip);
> +}
> +
> +static int cv1800_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm,
> +                            bool enable)
> +{
> +       struct cv1800_pwm *priv = to_cv1800_pwm_dev(chip);
> +       u32 pwm_enable;
> +
> +       regmap_read(priv->map, PWM_CV1800_START, &pwm_enable);
> +       pwm_enable &= PWM_CV1800_START_MASK(pwm->hwpwm);
> +
> +       /*
> +        * If the parameters are changed during runtime, Register needs
> +        * to be updated to take effect.
> +        */
> +       if (pwm_enable && enable) {
> +               regmap_update_bits(priv->map, PWM_CV1800_UPDATE,
> +                                  PWM_CV1800_UPDATE_MASK(pwm->hwpwm),
> +                                  PWM_CV1800_REG_ENABLE(pwm->hwpwm));
> +               regmap_update_bits(priv->map, PWM_CV1800_UPDATE,
> +                                  PWM_CV1800_UPDATE_MASK(pwm->hwpwm),
> +                                  PWM_CV1800_REG_DISABLE);
> +       } else if (!pwm_enable && enable) {
> +               regmap_update_bits(priv->map, PWM_CV1800_OE,
> +                                  PWM_CV1800_OE_MASK(pwm->hwpwm),
> +                                  PWM_CV1800_REG_ENABLE(pwm->hwpwm));
> +               regmap_update_bits(priv->map, PWM_CV1800_START,
> +                                  PWM_CV1800_START_MASK(pwm->hwpwm),
> +                                  PWM_CV1800_REG_ENABLE(pwm->hwpwm));
> +       } else if (pwm_enable && !enable) {
> +               regmap_update_bits(priv->map, PWM_CV1800_OE,
> +                                  PWM_CV1800_OE_MASK(pwm->hwpwm),
> +                                  PWM_CV1800_REG_DISABLE);
> +               regmap_update_bits(priv->map, PWM_CV1800_START,
> +                                  PWM_CV1800_START_MASK(pwm->hwpwm),
> +                                  PWM_CV1800_REG_DISABLE);
> +       }
> +
> +       return 0;
> +}
> +
> +static int cv1800_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
> +                           const struct pwm_state *state)
> +{
> +       struct cv1800_pwm *priv = to_cv1800_pwm_dev(chip);
> +       u32 period_val, hlperiod_val;
> +       u64 tem;
> +
> +       if (state->polarity != PWM_POLARITY_NORMAL)
> +               return -EINVAL;
> +
> +       tem = mul_u64_u64_div_u64(state->period, priv->clk_rate, NSEC_PER_SEC);
> +       if (tem > PWM_CV1800_MAXPERIOD || tem < PWM_CV1800_MINPERIOD)
> +               return -EINVAL;
> +       period_val = (u32)tem;
> +
> +       tem = mul_u64_u64_div_u64(state->period - state->duty_cycle,
> +                                 priv->clk_rate, NSEC_PER_SEC);
> +       if (tem > period_val)
> +               return -EINVAL;
> +       hlperiod_val = (u32)tem;
> +
> +       regmap_write(priv->map, PWM_CV1800_PERIOD(pwm->hwpwm), period_val);
> +       regmap_write(priv->map, PWM_CV1800_HLPERIOD(pwm->hwpwm), hlperiod_val);
> +
> +       cv1800_pwm_enable(chip, pwm, state->enabled);
> +
> +       return 0;
> +}
> +
> +static int cv1800_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
> +                               struct pwm_state *state)
> +{
> +       struct cv1800_pwm *priv = to_cv1800_pwm_dev(chip);
> +       u32 period_val, hlperiod_val;
> +       u64 period_ns = 0;
> +       u64 duty_ns = 0;
> +       u32 enable = 0;
> +
> +       regmap_read(priv->map, PWM_CV1800_PERIOD(pwm->hwpwm), &period_val);
> +       regmap_read(priv->map, PWM_CV1800_HLPERIOD(pwm->hwpwm), &hlperiod_val);
> +
> +       if (period_val != PWM_CV1800_PERIOD_RESET ||
> +           hlperiod_val != PWM_CV1800_HLPERIOD_RESET) {
> +               period_ns = DIV_ROUND_UP_ULL(period_val * NSEC_PER_SEC, priv->clk_rate);
> +               duty_ns = DIV_ROUND_UP_ULL(hlperiod_val * period_ns, period_val);
> +
> +               regmap_read(priv->map, PWM_CV1800_START, &enable);
> +
> +               enable &= PWM_CV1800_START_MASK(pwm->hwpwm);
> +       }
> +
> +       state->period = period_ns;
> +       state->duty_cycle = duty_ns;
> +       state->enabled = enable;
> +       state->polarity = PWM_POLARITY_NORMAL;
> +
> +       return 0;
> +}
> +
> +static const struct pwm_ops cv1800_pwm_ops = {
> +       .apply = cv1800_pwm_apply,
> +       .get_state = cv1800_pwm_get_state,
> +};
> +
> +static void devm_clk_rate_exclusive_put(void *data)
> +{
> +       struct clk *clk = data;
> +
> +       clk_rate_exclusive_put(clk);
> +}
> +
> +static int cv1800_pwm_probe(struct platform_device *pdev)
> +{
> +       struct device *dev = &pdev->dev;
> +       struct cv1800_pwm *priv;
> +       void __iomem *base;
> +       int ret;
> +
> +       priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> +       if (!priv)
> +               return -ENOMEM;
> +
> +       base = devm_platform_ioremap_resource(pdev, 0);
> +       if (IS_ERR(base))
> +               return PTR_ERR(base);
> +
> +       priv->map = devm_regmap_init_mmio(&pdev->dev, base,
> +                                         &cv1800_pwm_regmap_config);
> +       if (IS_ERR(priv->map))
> +               return PTR_ERR(priv->map);
> +
> +       priv->clk = devm_clk_get_enabled(&pdev->dev, NULL);
> +       if (IS_ERR(priv->clk))
> +               return dev_err_probe(&pdev->dev, PTR_ERR(priv->clk),
> +                                    "clk not found\n");
> +
> +       ret = clk_rate_exclusive_get(priv->clk);
> +       if (ret)
> +               return dev_err_probe(&pdev->dev, ret,
> +                                    "failed to get exclusive rate\n");
> +
> +       ret = devm_add_action_or_reset(&pdev->dev, devm_clk_rate_exclusive_put,
> +                                      priv->clk);
> +       if (ret) {
> +               clk_rate_exclusive_put(priv->clk);
> +               return ret;
> +       }
> +
> +       priv->clk_rate = clk_get_rate(priv->clk);
> +       if (!priv->clk_rate)
> +               return dev_err_probe(&pdev->dev, -EINVAL,
> +                                    "Invalid clock rate: %lu\n", priv->clk_rate);
> +
> +       priv->chip.dev = dev;
> +       priv->chip.ops = &cv1800_pwm_ops;
> +       priv->chip.npwm = 4;
> +       priv->chip.atomic = true;
> +
> +       return devm_pwmchip_add(dev, &priv->chip);
> +}
> +
> +static const struct of_device_id cv1800_pwm_dt_ids[] = {
> +       { .compatible = "sophgo,cv1800-pwm" },
> +       {},
> +};
> +MODULE_DEVICE_TABLE(of, cv1800_pwm_dt_ids);
> +
> +static struct platform_driver cv1800_pwm_driver = {
> +       .driver = {
> +               .name = "cv1800-pwm",
> +               .of_match_table = cv1800_pwm_dt_ids,
> +       },
> +       .probe = cv1800_pwm_probe,
> +};
> +module_platform_driver(cv1800_pwm_driver);
> +
> +MODULE_AUTHOR("Jingbao Qiu");
> +MODULE_DESCRIPTION("Sophgo cv1800 PWM Driver");
> +MODULE_LICENSE("GPL");
> --
> 2.25.1
>
Uwe Kleine-König Feb. 20, 2024, 10:47 a.m. UTC | #2
Hello,

On Mon, Feb 12, 2024 at 08:17:29PM +0800, Jingbao Qiu wrote:
> Implement the PWM driver for CV1800.
> 
> Signed-off-by: Jingbao Qiu <qiujingbao.dlmu@gmail.com>
> ---
>  drivers/pwm/Kconfig      |  10 ++
>  drivers/pwm/Makefile     |   1 +
>  drivers/pwm/pwm-cv1800.c | 248 +++++++++++++++++++++++++++++++++++++++
>  3 files changed, 259 insertions(+)
>  create mode 100644 drivers/pwm/pwm-cv1800.c
> 
> diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
> index 4b956d661755..455f07af94f7 100644
> --- a/drivers/pwm/Kconfig
> +++ b/drivers/pwm/Kconfig
> @@ -186,6 +186,16 @@ config PWM_CROS_EC
>  	  PWM driver for exposing a PWM attached to the ChromeOS Embedded
>  	  Controller.
>  
> +config PWM_CV1800
> +	tristate "Sophgo CV1800 PWM driver"
> +	depends on ARCH_SOPHGO || COMPILE_TEST
> +	help
> +	  Generic PWM framework driver for the Sophgo CV1800 series
> +	  SoCs.
> +
> +	  To compile this driver as a module, build the dependecies
> +	  as modules, this will be called pwm-cv1800.
> +
>  config PWM_DWC_CORE
>  	tristate
>  	depends on HAS_IOMEM
> diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
> index c5ec9e168ee7..6c3c4a07a316 100644
> --- a/drivers/pwm/Makefile
> +++ b/drivers/pwm/Makefile
> @@ -15,6 +15,7 @@ obj-$(CONFIG_PWM_CLK)		+= pwm-clk.o
>  obj-$(CONFIG_PWM_CLPS711X)	+= pwm-clps711x.o
>  obj-$(CONFIG_PWM_CRC)		+= pwm-crc.o
>  obj-$(CONFIG_PWM_CROS_EC)	+= pwm-cros-ec.o
> +obj-$(CONFIG_PWM_CV1800)	+= pwm-cv1800.o
>  obj-$(CONFIG_PWM_DWC_CORE)	+= pwm-dwc-core.o
>  obj-$(CONFIG_PWM_DWC)		+= pwm-dwc.o
>  obj-$(CONFIG_PWM_EP93XX)	+= pwm-ep93xx.o
> diff --git a/drivers/pwm/pwm-cv1800.c b/drivers/pwm/pwm-cv1800.c
> new file mode 100644
> index 000000000000..3d7f2ff3a6c2
> --- /dev/null
> +++ b/drivers/pwm/pwm-cv1800.c
> @@ -0,0 +1,248 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * pwm-cv1800.c: PWM driver for Sophgo cv1800
> + *
> + * Author: Jingbao Qiu <qiujingbao.dlmu@gmail.com>
> + *
> + * Limitations:
> + * - It output low when PWM channel disabled.
> + * - This pwm device supports dynamic loading of PWM parameters. When PWMSTART
> + *   is written from 0 to 1, the register value (HLPERIODn, PERIODn) will be
> + *   temporarily stored inside the PWM. If you want to dynamically change the
> + *   waveform during PWM output, after writing the new value to HLPERIODn and
> + *   PERIODn, write 1 and then 0 to PWMUPDATE[n] to make the new value effective.
> + * - Supports up to Rate/2 output, and the lowest is about Rate/(2^30-1).
> + * - By setting HLPERIODn to 0, can produce 100% duty cycle.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/pwm.h>
> +#include <linux/regmap.h>
> +
> +#define PWM_CV1800_HLPERIOD_BASE       0x00
> +#define PWM_CV1800_PERIOD_BASE         0x04
> +#define PWM_CV1800_PWM_CV1800_POLARITY 0x40
> +#define PWM_CV1800_START               0x44
> +#define PWM_CV1800_DONE                0x48
> +#define PWM_CV1800_UPDATE              0x4c
> +#define PWM_CV1800_OE                  0xd0
> +#define PWM_CV1800_HLPERIOD_SHIFT      0x08
> +#define PWM_CV1800_PERIOD_SHIFT        0x08
> +
> +#define PWM_CV1800_HLPERIOD(n)         \
> +	(PWM_CV1800_HLPERIOD_BASE + ((n) * PWM_CV1800_HLPERIOD_SHIFT))
> +#define PWM_CV1800_PERIOD(n)           \
> +	(PWM_CV1800_PERIOD_BASE + ((n) * PWM_CV1800_PERIOD_SHIFT))

I would have used a plain 0x08 instead of PWM_CV1800_HLPERIOD_SHIFT and
PWM_CV1800_PERIOD_SHIFT.

> +#define PWM_CV1800_UPDATE_MASK(n) (BIT(0) << (n))
> +#define PWM_CV1800_OE_MASK(n)     (BIT(0) << (n))
> +#define PWM_CV1800_START_MASK(n)  (BIT(0) << (n))
> +
> +#define PWM_CV1800_MAXPERIOD      (BIT(30) - 1)
> +#define PWM_CV1800_MINPERIOD      BIT(1)
> +#define PWM_CV1800_MINHLPERIOD    BIT(0)
> +#define PWM_CV1800_PERIOD_RESET   BIT(1)
> +#define PWM_CV1800_HLPERIOD_RESET BIT(0)
> +#define PWM_CV1800_REG_DISABLE    0x0U
> +#define PWM_CV1800_REG_ENABLE(n)  (BIT(0) << (n))
> +
> +struct cv1800_pwm {
> +	struct pwm_chip chip;
> +	struct regmap *map;
> +	struct clk *clk;
> +	unsigned long clk_rate;
> +};
> +
> +static const struct regmap_config cv1800_pwm_regmap_config = {
> +	.reg_bits = 32,
> +	.val_bits = 32,
> +	.reg_stride = 4,
> +};
> +
> +static inline struct cv1800_pwm *to_cv1800_pwm_dev(struct pwm_chip *chip)
> +{
> +	return container_of(chip, struct cv1800_pwm, chip);

Please rework the driver to use pwmchip_alloc(). See
https://lore.kernel.org/linux-pwm/a37a167364366b6cbe2dd299dce02731706213b2.1707900770.git.u.kleine-koenig@pengutronix.de/T/#u
for a simple example for such a rework.

> +}
> +
> +static int cv1800_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm,
> +			     bool enable)
> +{
> +	struct cv1800_pwm *priv = to_cv1800_pwm_dev(chip);
> +	u32 pwm_enable;
> +
> +	regmap_read(priv->map, PWM_CV1800_START, &pwm_enable);
> +	pwm_enable &= PWM_CV1800_START_MASK(pwm->hwpwm);
> +
> +	/*
> +	 * If the parameters are changed during runtime, Register needs
> +	 * to be updated to take effect.
> +	 */
> +	if (pwm_enable && enable) {
> +		regmap_update_bits(priv->map, PWM_CV1800_UPDATE,
> +				   PWM_CV1800_UPDATE_MASK(pwm->hwpwm),
> +				   PWM_CV1800_REG_ENABLE(pwm->hwpwm));
> +		regmap_update_bits(priv->map, PWM_CV1800_UPDATE,
> +				   PWM_CV1800_UPDATE_MASK(pwm->hwpwm),
> +				   PWM_CV1800_REG_DISABLE);
> +	} else if (!pwm_enable && enable) {
> +		regmap_update_bits(priv->map, PWM_CV1800_OE,
> +				   PWM_CV1800_OE_MASK(pwm->hwpwm),
> +				   PWM_CV1800_REG_ENABLE(pwm->hwpwm));
> +		regmap_update_bits(priv->map, PWM_CV1800_START,
> +				   PWM_CV1800_START_MASK(pwm->hwpwm),
> +				   PWM_CV1800_REG_ENABLE(pwm->hwpwm));
> +	} else if (pwm_enable && !enable) {
> +		regmap_update_bits(priv->map, PWM_CV1800_OE,
> +				   PWM_CV1800_OE_MASK(pwm->hwpwm),
> +				   PWM_CV1800_REG_DISABLE);
> +		regmap_update_bits(priv->map, PWM_CV1800_START,
> +				   PWM_CV1800_START_MASK(pwm->hwpwm),
> +				   PWM_CV1800_REG_DISABLE);
> +	}
> +
> +	return 0;
> +}
> +
> +static int cv1800_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
> +			    const struct pwm_state *state)
> +{
> +	struct cv1800_pwm *priv = to_cv1800_pwm_dev(chip);
> +	u32 period_val, hlperiod_val;
> +	u64 tem;
> +
> +	if (state->polarity != PWM_POLARITY_NORMAL)
> +		return -EINVAL;
> +
> +	tem = mul_u64_u64_div_u64(state->period, priv->clk_rate, NSEC_PER_SEC);
> +	if (tem > PWM_CV1800_MAXPERIOD || tem < PWM_CV1800_MINPERIOD)
> +		return -EINVAL;

Please use:

	if (tem < PWM_CV1800_MINPERIOD)
		return -EINVAL
	if (tem > PWM_CV1800_MAXPERIOD)
		tem = PWM_CV1800_MAXPERIOD;

> +	period_val = (u32)tem;
> +
> +	tem = mul_u64_u64_div_u64(state->period - state->duty_cycle,
> +				  priv->clk_rate, NSEC_PER_SEC);

Given that you're supposed to configure the biggest duty_cycle not
bigger than the requested value, you have to round up here.

Best regards
Uwe
Jingbao Qiu Feb. 20, 2024, 11:44 a.m. UTC | #3
On Tue, Feb 20, 2024 at 6:48 PM Uwe Kleine-König
<u.kleine-koenig@pengutronix.de> wrote:
>
> Hello,
>
> On Mon, Feb 12, 2024 at 08:17:29PM +0800, Jingbao Qiu wrote:
> > Implement the PWM driver for CV1800.
> >
> > Signed-off-by: Jingbao Qiu <qiujingbao.dlmu@gmail.com>
> > ---
> >  drivers/pwm/Kconfig      |  10 ++
> >  drivers/pwm/Makefile     |   1 +
> >  drivers/pwm/pwm-cv1800.c | 248 +++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 259 insertions(+)
> >  create mode 100644 drivers/pwm/pwm-cv1800.c
> >
> > diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
> > index 4b956d661755..455f07af94f7 100644
> > --- a/drivers/pwm/Kconfig
> > +++ b/drivers/pwm/Kconfig
> > @@ -186,6 +186,16 @@ config PWM_CROS_EC
> >         PWM driver for exposing a PWM attached to the ChromeOS Embedded
> >         Controller.
> >
> > +config PWM_CV1800
> > +     tristate "Sophgo CV1800 PWM driver"
> > +     depends on ARCH_SOPHGO || COMPILE_TEST
> > +     help
> > +       Generic PWM framework driver for the Sophgo CV1800 series
> > +       SoCs.
> > +
> > +       To compile this driver as a module, build the dependecies
> > +       as modules, this will be called pwm-cv1800.
> > +
> >  config PWM_DWC_CORE
> >       tristate
> >       depends on HAS_IOMEM
> > diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
> > index c5ec9e168ee7..6c3c4a07a316 100644
> > --- a/drivers/pwm/Makefile
> > +++ b/drivers/pwm/Makefile
> > @@ -15,6 +15,7 @@ obj-$(CONFIG_PWM_CLK)               += pwm-clk.o
> >  obj-$(CONFIG_PWM_CLPS711X)   += pwm-clps711x.o
> >  obj-$(CONFIG_PWM_CRC)                += pwm-crc.o
> >  obj-$(CONFIG_PWM_CROS_EC)    += pwm-cros-ec.o
> > +obj-$(CONFIG_PWM_CV1800)     += pwm-cv1800.o
> >  obj-$(CONFIG_PWM_DWC_CORE)   += pwm-dwc-core.o
> >  obj-$(CONFIG_PWM_DWC)                += pwm-dwc.o
> >  obj-$(CONFIG_PWM_EP93XX)     += pwm-ep93xx.o
> > diff --git a/drivers/pwm/pwm-cv1800.c b/drivers/pwm/pwm-cv1800.c
> > new file mode 100644
> > index 000000000000..3d7f2ff3a6c2
> > --- /dev/null
> > +++ b/drivers/pwm/pwm-cv1800.c
> > @@ -0,0 +1,248 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * pwm-cv1800.c: PWM driver for Sophgo cv1800
> > + *
> > + * Author: Jingbao Qiu <qiujingbao.dlmu@gmail.com>
> > + *
> > + * Limitations:
> > + * - It output low when PWM channel disabled.
> > + * - This pwm device supports dynamic loading of PWM parameters. When PWMSTART
> > + *   is written from 0 to 1, the register value (HLPERIODn, PERIODn) will be
> > + *   temporarily stored inside the PWM. If you want to dynamically change the
> > + *   waveform during PWM output, after writing the new value to HLPERIODn and
> > + *   PERIODn, write 1 and then 0 to PWMUPDATE[n] to make the new value effective.
> > + * - Supports up to Rate/2 output, and the lowest is about Rate/(2^30-1).
> > + * - By setting HLPERIODn to 0, can produce 100% duty cycle.
> > + */
> > +
> > +#include <linux/clk.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/of.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/pwm.h>
> > +#include <linux/regmap.h>
> > +
> > +#define PWM_CV1800_HLPERIOD_BASE       0x00
> > +#define PWM_CV1800_PERIOD_BASE         0x04
> > +#define PWM_CV1800_PWM_CV1800_POLARITY 0x40
> > +#define PWM_CV1800_START               0x44
> > +#define PWM_CV1800_DONE                0x48
> > +#define PWM_CV1800_UPDATE              0x4c
> > +#define PWM_CV1800_OE                  0xd0
> > +#define PWM_CV1800_HLPERIOD_SHIFT      0x08
> > +#define PWM_CV1800_PERIOD_SHIFT        0x08
> > +
> > +#define PWM_CV1800_HLPERIOD(n)         \
> > +     (PWM_CV1800_HLPERIOD_BASE + ((n) * PWM_CV1800_HLPERIOD_SHIFT))
> > +#define PWM_CV1800_PERIOD(n)           \
> > +     (PWM_CV1800_PERIOD_BASE + ((n) * PWM_CV1800_PERIOD_SHIFT))
>
> I would have used a plain 0x08 instead of PWM_CV1800_HLPERIOD_SHIFT and
> PWM_CV1800_PERIOD_SHIFT.

I will fix it.

>
> > +#define PWM_CV1800_UPDATE_MASK(n) (BIT(0) << (n))
> > +#define PWM_CV1800_OE_MASK(n)     (BIT(0) << (n))
> > +#define PWM_CV1800_START_MASK(n)  (BIT(0) << (n))
> > +
> > +#define PWM_CV1800_MAXPERIOD      (BIT(30) - 1)
> > +#define PWM_CV1800_MINPERIOD      BIT(1)
> > +#define PWM_CV1800_MINHLPERIOD    BIT(0)
> > +#define PWM_CV1800_PERIOD_RESET   BIT(1)
> > +#define PWM_CV1800_HLPERIOD_RESET BIT(0)
> > +#define PWM_CV1800_REG_DISABLE    0x0U
> > +#define PWM_CV1800_REG_ENABLE(n)  (BIT(0) << (n))
> > +
> > +struct cv1800_pwm {
> > +     struct pwm_chip chip;
> > +     struct regmap *map;
> > +     struct clk *clk;
> > +     unsigned long clk_rate;
> > +};
> > +
> > +static const struct regmap_config cv1800_pwm_regmap_config = {
> > +     .reg_bits = 32,
> > +     .val_bits = 32,
> > +     .reg_stride = 4,
> > +};
> > +
> > +static inline struct cv1800_pwm *to_cv1800_pwm_dev(struct pwm_chip *chip)
> > +{
> > +     return container_of(chip, struct cv1800_pwm, chip);
>
> Please rework the driver to use pwmchip_alloc(). See
> https://lore.kernel.org/linux-pwm/a37a167364366b6cbe2dd299dce02731706213b2.1707900770.git.u.kleine-koenig@pengutronix.de/T/#u
> for a simple example for such a rework.
>

I will fix it.

> > +}
> > +
> > +static int cv1800_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm,
> > +                          bool enable)
> > +{
> > +     struct cv1800_pwm *priv = to_cv1800_pwm_dev(chip);
> > +     u32 pwm_enable;
> > +
> > +     regmap_read(priv->map, PWM_CV1800_START, &pwm_enable);
> > +     pwm_enable &= PWM_CV1800_START_MASK(pwm->hwpwm);
> > +
> > +     /*
> > +      * If the parameters are changed during runtime, Register needs
> > +      * to be updated to take effect.
> > +      */
> > +     if (pwm_enable && enable) {
> > +             regmap_update_bits(priv->map, PWM_CV1800_UPDATE,
> > +                                PWM_CV1800_UPDATE_MASK(pwm->hwpwm),
> > +                                PWM_CV1800_REG_ENABLE(pwm->hwpwm));
> > +             regmap_update_bits(priv->map, PWM_CV1800_UPDATE,
> > +                                PWM_CV1800_UPDATE_MASK(pwm->hwpwm),
> > +                                PWM_CV1800_REG_DISABLE);
> > +     } else if (!pwm_enable && enable) {
> > +             regmap_update_bits(priv->map, PWM_CV1800_OE,
> > +                                PWM_CV1800_OE_MASK(pwm->hwpwm),
> > +                                PWM_CV1800_REG_ENABLE(pwm->hwpwm));
> > +             regmap_update_bits(priv->map, PWM_CV1800_START,
> > +                                PWM_CV1800_START_MASK(pwm->hwpwm),
> > +                                PWM_CV1800_REG_ENABLE(pwm->hwpwm));
> > +     } else if (pwm_enable && !enable) {
> > +             regmap_update_bits(priv->map, PWM_CV1800_OE,
> > +                                PWM_CV1800_OE_MASK(pwm->hwpwm),
> > +                                PWM_CV1800_REG_DISABLE);
> > +             regmap_update_bits(priv->map, PWM_CV1800_START,
> > +                                PWM_CV1800_START_MASK(pwm->hwpwm),
> > +                                PWM_CV1800_REG_DISABLE);
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static int cv1800_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
> > +                         const struct pwm_state *state)
> > +{
> > +     struct cv1800_pwm *priv = to_cv1800_pwm_dev(chip);
> > +     u32 period_val, hlperiod_val;
> > +     u64 tem;
> > +
> > +     if (state->polarity != PWM_POLARITY_NORMAL)
> > +             return -EINVAL;
> > +
> > +     tem = mul_u64_u64_div_u64(state->period, priv->clk_rate, NSEC_PER_SEC);
> > +     if (tem > PWM_CV1800_MAXPERIOD || tem < PWM_CV1800_MINPERIOD)
> > +             return -EINVAL;
>
> Please use:
>
>         if (tem < PWM_CV1800_MINPERIOD)
>                 return -EINVAL
>         if (tem > PWM_CV1800_MAXPERIOD)
>                 tem = PWM_CV1800_MAXPERIOD;
>

I will fix it.

> > +     period_val = (u32)tem;
> > +
> > +     tem = mul_u64_u64_div_u64(state->period - state->duty_cycle,
> > +                               priv->clk_rate, NSEC_PER_SEC);
>
> Given that you're supposed to configure the biggest duty_cycle not
> bigger than the requested value, you have to round up here.
>

I will fix it.
Thank you for your patient reply.

Best regards
Jingbao Qiu
diff mbox series

Patch

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 4b956d661755..455f07af94f7 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -186,6 +186,16 @@  config PWM_CROS_EC
 	  PWM driver for exposing a PWM attached to the ChromeOS Embedded
 	  Controller.
 
+config PWM_CV1800
+	tristate "Sophgo CV1800 PWM driver"
+	depends on ARCH_SOPHGO || COMPILE_TEST
+	help
+	  Generic PWM framework driver for the Sophgo CV1800 series
+	  SoCs.
+
+	  To compile this driver as a module, build the dependecies
+	  as modules, this will be called pwm-cv1800.
+
 config PWM_DWC_CORE
 	tristate
 	depends on HAS_IOMEM
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index c5ec9e168ee7..6c3c4a07a316 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -15,6 +15,7 @@  obj-$(CONFIG_PWM_CLK)		+= pwm-clk.o
 obj-$(CONFIG_PWM_CLPS711X)	+= pwm-clps711x.o
 obj-$(CONFIG_PWM_CRC)		+= pwm-crc.o
 obj-$(CONFIG_PWM_CROS_EC)	+= pwm-cros-ec.o
+obj-$(CONFIG_PWM_CV1800)	+= pwm-cv1800.o
 obj-$(CONFIG_PWM_DWC_CORE)	+= pwm-dwc-core.o
 obj-$(CONFIG_PWM_DWC)		+= pwm-dwc.o
 obj-$(CONFIG_PWM_EP93XX)	+= pwm-ep93xx.o
diff --git a/drivers/pwm/pwm-cv1800.c b/drivers/pwm/pwm-cv1800.c
new file mode 100644
index 000000000000..3d7f2ff3a6c2
--- /dev/null
+++ b/drivers/pwm/pwm-cv1800.c
@@ -0,0 +1,248 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * pwm-cv1800.c: PWM driver for Sophgo cv1800
+ *
+ * Author: Jingbao Qiu <qiujingbao.dlmu@gmail.com>
+ *
+ * Limitations:
+ * - It output low when PWM channel disabled.
+ * - This pwm device supports dynamic loading of PWM parameters. When PWMSTART
+ *   is written from 0 to 1, the register value (HLPERIODn, PERIODn) will be
+ *   temporarily stored inside the PWM. If you want to dynamically change the
+ *   waveform during PWM output, after writing the new value to HLPERIODn and
+ *   PERIODn, write 1 and then 0 to PWMUPDATE[n] to make the new value effective.
+ * - Supports up to Rate/2 output, and the lowest is about Rate/(2^30-1).
+ * - By setting HLPERIODn to 0, can produce 100% duty cycle.
+ */
+
+#include <linux/clk.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/regmap.h>
+
+#define PWM_CV1800_HLPERIOD_BASE       0x00
+#define PWM_CV1800_PERIOD_BASE         0x04
+#define PWM_CV1800_PWM_CV1800_POLARITY 0x40
+#define PWM_CV1800_START               0x44
+#define PWM_CV1800_DONE                0x48
+#define PWM_CV1800_UPDATE              0x4c
+#define PWM_CV1800_OE                  0xd0
+#define PWM_CV1800_HLPERIOD_SHIFT      0x08
+#define PWM_CV1800_PERIOD_SHIFT        0x08
+
+#define PWM_CV1800_HLPERIOD(n)         \
+	(PWM_CV1800_HLPERIOD_BASE + ((n) * PWM_CV1800_HLPERIOD_SHIFT))
+#define PWM_CV1800_PERIOD(n)           \
+	(PWM_CV1800_PERIOD_BASE + ((n) * PWM_CV1800_PERIOD_SHIFT))
+
+#define PWM_CV1800_UPDATE_MASK(n) (BIT(0) << (n))
+#define PWM_CV1800_OE_MASK(n)     (BIT(0) << (n))
+#define PWM_CV1800_START_MASK(n)  (BIT(0) << (n))
+
+#define PWM_CV1800_MAXPERIOD      (BIT(30) - 1)
+#define PWM_CV1800_MINPERIOD      BIT(1)
+#define PWM_CV1800_MINHLPERIOD    BIT(0)
+#define PWM_CV1800_PERIOD_RESET   BIT(1)
+#define PWM_CV1800_HLPERIOD_RESET BIT(0)
+#define PWM_CV1800_REG_DISABLE    0x0U
+#define PWM_CV1800_REG_ENABLE(n)  (BIT(0) << (n))
+
+struct cv1800_pwm {
+	struct pwm_chip chip;
+	struct regmap *map;
+	struct clk *clk;
+	unsigned long clk_rate;
+};
+
+static const struct regmap_config cv1800_pwm_regmap_config = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+};
+
+static inline struct cv1800_pwm *to_cv1800_pwm_dev(struct pwm_chip *chip)
+{
+	return container_of(chip, struct cv1800_pwm, chip);
+}
+
+static int cv1800_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm,
+			     bool enable)
+{
+	struct cv1800_pwm *priv = to_cv1800_pwm_dev(chip);
+	u32 pwm_enable;
+
+	regmap_read(priv->map, PWM_CV1800_START, &pwm_enable);
+	pwm_enable &= PWM_CV1800_START_MASK(pwm->hwpwm);
+
+	/*
+	 * If the parameters are changed during runtime, Register needs
+	 * to be updated to take effect.
+	 */
+	if (pwm_enable && enable) {
+		regmap_update_bits(priv->map, PWM_CV1800_UPDATE,
+				   PWM_CV1800_UPDATE_MASK(pwm->hwpwm),
+				   PWM_CV1800_REG_ENABLE(pwm->hwpwm));
+		regmap_update_bits(priv->map, PWM_CV1800_UPDATE,
+				   PWM_CV1800_UPDATE_MASK(pwm->hwpwm),
+				   PWM_CV1800_REG_DISABLE);
+	} else if (!pwm_enable && enable) {
+		regmap_update_bits(priv->map, PWM_CV1800_OE,
+				   PWM_CV1800_OE_MASK(pwm->hwpwm),
+				   PWM_CV1800_REG_ENABLE(pwm->hwpwm));
+		regmap_update_bits(priv->map, PWM_CV1800_START,
+				   PWM_CV1800_START_MASK(pwm->hwpwm),
+				   PWM_CV1800_REG_ENABLE(pwm->hwpwm));
+	} else if (pwm_enable && !enable) {
+		regmap_update_bits(priv->map, PWM_CV1800_OE,
+				   PWM_CV1800_OE_MASK(pwm->hwpwm),
+				   PWM_CV1800_REG_DISABLE);
+		regmap_update_bits(priv->map, PWM_CV1800_START,
+				   PWM_CV1800_START_MASK(pwm->hwpwm),
+				   PWM_CV1800_REG_DISABLE);
+	}
+
+	return 0;
+}
+
+static int cv1800_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			    const struct pwm_state *state)
+{
+	struct cv1800_pwm *priv = to_cv1800_pwm_dev(chip);
+	u32 period_val, hlperiod_val;
+	u64 tem;
+
+	if (state->polarity != PWM_POLARITY_NORMAL)
+		return -EINVAL;
+
+	tem = mul_u64_u64_div_u64(state->period, priv->clk_rate, NSEC_PER_SEC);
+	if (tem > PWM_CV1800_MAXPERIOD || tem < PWM_CV1800_MINPERIOD)
+		return -EINVAL;
+	period_val = (u32)tem;
+
+	tem = mul_u64_u64_div_u64(state->period - state->duty_cycle,
+				  priv->clk_rate, NSEC_PER_SEC);
+	if (tem > period_val)
+		return -EINVAL;
+	hlperiod_val = (u32)tem;
+
+	regmap_write(priv->map, PWM_CV1800_PERIOD(pwm->hwpwm), period_val);
+	regmap_write(priv->map, PWM_CV1800_HLPERIOD(pwm->hwpwm), hlperiod_val);
+
+	cv1800_pwm_enable(chip, pwm, state->enabled);
+
+	return 0;
+}
+
+static int cv1800_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
+				struct pwm_state *state)
+{
+	struct cv1800_pwm *priv = to_cv1800_pwm_dev(chip);
+	u32 period_val, hlperiod_val;
+	u64 period_ns = 0;
+	u64 duty_ns = 0;
+	u32 enable = 0;
+
+	regmap_read(priv->map, PWM_CV1800_PERIOD(pwm->hwpwm), &period_val);
+	regmap_read(priv->map, PWM_CV1800_HLPERIOD(pwm->hwpwm), &hlperiod_val);
+
+	if (period_val != PWM_CV1800_PERIOD_RESET ||
+	    hlperiod_val != PWM_CV1800_HLPERIOD_RESET) {
+		period_ns = DIV_ROUND_UP_ULL(period_val * NSEC_PER_SEC, priv->clk_rate);
+		duty_ns = DIV_ROUND_UP_ULL(hlperiod_val * period_ns, period_val);
+
+		regmap_read(priv->map, PWM_CV1800_START, &enable);
+
+		enable &= PWM_CV1800_START_MASK(pwm->hwpwm);
+	}
+
+	state->period = period_ns;
+	state->duty_cycle = duty_ns;
+	state->enabled = enable;
+	state->polarity = PWM_POLARITY_NORMAL;
+
+	return 0;
+}
+
+static const struct pwm_ops cv1800_pwm_ops = {
+	.apply = cv1800_pwm_apply,
+	.get_state = cv1800_pwm_get_state,
+};
+
+static void devm_clk_rate_exclusive_put(void *data)
+{
+	struct clk *clk = data;
+
+	clk_rate_exclusive_put(clk);
+}
+
+static int cv1800_pwm_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct cv1800_pwm *priv;
+	void __iomem *base;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	priv->map = devm_regmap_init_mmio(&pdev->dev, base,
+					  &cv1800_pwm_regmap_config);
+	if (IS_ERR(priv->map))
+		return PTR_ERR(priv->map);
+
+	priv->clk = devm_clk_get_enabled(&pdev->dev, NULL);
+	if (IS_ERR(priv->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(priv->clk),
+				     "clk not found\n");
+
+	ret = clk_rate_exclusive_get(priv->clk);
+	if (ret)
+		return dev_err_probe(&pdev->dev, ret,
+				     "failed to get exclusive rate\n");
+
+	ret = devm_add_action_or_reset(&pdev->dev, devm_clk_rate_exclusive_put,
+				       priv->clk);
+	if (ret) {
+		clk_rate_exclusive_put(priv->clk);
+		return ret;
+	}
+
+	priv->clk_rate = clk_get_rate(priv->clk);
+	if (!priv->clk_rate)
+		return dev_err_probe(&pdev->dev, -EINVAL,
+				     "Invalid clock rate: %lu\n", priv->clk_rate);
+
+	priv->chip.dev = dev;
+	priv->chip.ops = &cv1800_pwm_ops;
+	priv->chip.npwm = 4;
+	priv->chip.atomic = true;
+
+	return devm_pwmchip_add(dev, &priv->chip);
+}
+
+static const struct of_device_id cv1800_pwm_dt_ids[] = {
+	{ .compatible = "sophgo,cv1800-pwm" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, cv1800_pwm_dt_ids);
+
+static struct platform_driver cv1800_pwm_driver = {
+	.driver = {
+		.name = "cv1800-pwm",
+		.of_match_table = cv1800_pwm_dt_ids,
+	},
+	.probe = cv1800_pwm_probe,
+};
+module_platform_driver(cv1800_pwm_driver);
+
+MODULE_AUTHOR("Jingbao Qiu");
+MODULE_DESCRIPTION("Sophgo cv1800 PWM Driver");
+MODULE_LICENSE("GPL");