Re: [PATCH v5 2/4] pwm: starfive: Add PWM driver support

From: Emil Renner Berthing
Date: Mon Sep 25 2023 - 06:32:03 EST

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In reply to: William Qiu: "Re: [PATCH v5 2/4] pwm: starfive: Add PWM driver support"
Next in thread: William Qiu: "Re: [PATCH v5 2/4] pwm: starfive: Add PWM driver support"
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William Qiu wrote:
>
>
> On 2023/9/23 20:08, Emil Renner Berthing wrote:
> > William Qiu wrote:
> >> Add Pulse Width Modulation driver support for StarFive
> >> JH7100 and JH7110 SoC.
> >>
> >> Co-developed-by: Hal Feng <hal.feng@xxxxxxxxxxxxxxxx>
> >> Signed-off-by: Hal Feng <hal.feng@xxxxxxxxxxxxxxxx>
> >> Signed-off-by: William Qiu <william.qiu@xxxxxxxxxxxxxxxx>
> >> ---
> >> MAINTAINERS | 7 ++
> >> drivers/pwm/Kconfig | 9 ++
> >> drivers/pwm/Makefile | 1 +
> >> drivers/pwm/pwm-starfive.c | 190 +++++++++++++++++++++++++++++++++++++
> >> 4 files changed, 207 insertions(+)
> >> create mode 100644 drivers/pwm/pwm-starfive.c
> >>
> >> diff --git a/MAINTAINERS b/MAINTAINERS
> >> index bf0f54c24f81..bc2155bd2712 100644
> >> --- a/MAINTAINERS
> >> +++ b/MAINTAINERS
> >> @@ -20495,6 +20495,13 @@ 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@xxxxxxxxxxxxxxxx>
> >> +M: Hal Feng <hal.feng@xxxxxxxxxxxxxxxx>
> >> +S: Supported
> >> +F: Documentation/devicetree/bindings/pwm/starfive,jh7100-pwm.yaml
> >> +F: drivers/pwm/pwm-starfive-ptc.c
> >> +
> >> STARFIVE JH71X0 RESET CONTROLLER DRIVERS
> >> M: Emil Renner Berthing <kernel@xxxxxxxx>
> >> M: Hal Feng <hal.feng@xxxxxxxxxxxxxxxx>
> >> diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
> >> index 8ebcddf91f7b..e2ee0169f6e4 100644
> >> --- a/drivers/pwm/Kconfig
> >> +++ b/drivers/pwm/Kconfig
> >> @@ -569,6 +569,15 @@ config PWM_SPRD
> >> To compile this driver as a module, choose M here: the module
> >> will be called pwm-sprd.
> >>
> >> +config PWM_STARFIVE
> >> + tristate "StarFive PWM support"
> >> + depends on ARCH_STARFIVE || COMPILE_TEST
> >> + 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.
> >> +
> >> config PWM_STI
> >> tristate "STiH4xx PWM support"
> >> depends on ARCH_STI || COMPILE_TEST
> >> diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
> >> index c822389c2a24..93b954376873 100644
> >> --- a/drivers/pwm/Makefile
> >> +++ b/drivers/pwm/Makefile
> >> @@ -52,6 +52,7 @@ 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-$(CONFIG_PWM_STARFIVE) += pwm-starfive.o
> >> obj-$(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.c b/drivers/pwm/pwm-starfive.c
> >
> > Hi William,
> >
> > You never answered my questions about what PTC is short for and if there are
> > other PWMs on the JH7110. You just removed -ptc from the name of this file..
> >
> Hi Emil,
>
> The PTC, short for PWM/TIMER/CONUTER, comes from OpenCore's ip, but only PWM
> mode is used in the JH7110. So the register still has the word "PTC".
> s the best way to change all the prefix to STARFIVE?

I see. Yeah, since you're only using the P from PTC the PTC name doesn't make a
lot of sense anymore. I'd just call this whole driver
STARFIVE_PWM_/starfive_pwm_ consistently.

>
> Best regards,
> William
> >> new file mode 100644
> >> index 000000000000..d390349fc95d
> >> --- /dev/null
> >> +++ b/drivers/pwm/pwm-starfive.c
> >> @@ -0,0 +1,190 @@
> >> +// SPDX-License-Identifier: GPL-2.0
> >> +/*
> >> + * PWM driver for the StarFive JH71x0 SoC
> >> + *
> >> + * Copyright (C) 2018-2023 StarFive Technology Co., Ltd.
> >> + */
> >> +
> >> +#include <linux/clk.h>
> >> +#include <linux/io.h>
> >> +#include <linux/module.h>
> >> +#include <linux/platform_device.h>
> >> +#include <linux/pwm.h>
> >> +#include <linux/reset.h>
> >> +#include <linux/slab.h>
> >> +
> >> +/* Access PTC register (CNTR, HRC, LRC and CTRL) */
> >> +#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)
> >
> > ..but these defines
> >
> >> +
> >> +/* PTC_RPTC_CTRL register bits*/
> >> +#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)
> >
> > ..and these defines are still prefixed with *PTC where I'd expect something like
> > STARFIVE_PWM_, and below structs and function names are also still
> > using starfive_pwm_ptc_
> > where I'd expect starfive_pwm_. Please be consistant in your naming.
> >
> >> +struct starfive_pwm_ptc_device {
> >> + struct pwm_chip chip;
> >> + struct clk *clk;
> >> + struct reset_control *rst;
> >> + void __iomem *regs;
> >> + u32 clk_rate; /* PWM APB clock frequency */
> >> +};
> >> +
> >> +static inline struct starfive_pwm_ptc_device *
> >> +chip_to_starfive_ptc(struct pwm_chip *chip)
> >> +
> >> +{
> >> + return container_of(chip, 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 period_data, duty_data, ctrl_data;
> >> +
> >> + period_data = readl(REG_PTC_RPTC_LRC(pwm->regs, dev->hwpwm));
> >> + duty_data = readl(REG_PTC_RPTC_HRC(pwm->regs, dev->hwpwm));
> >> + ctrl_data = readl(REG_PTC_RPTC_CTRL(pwm->regs, dev->hwpwm));
> >> +
> >> + state->period = DIV_ROUND_CLOSEST_ULL((u64)period_data * NSEC_PER_SEC, pwm->clk_rate);
> >> + state->duty_cycle = DIV_ROUND_CLOSEST_ULL((u64)duty_data * NSEC_PER_SEC, pwm->clk_rate);
> >> + state->polarity = PWM_POLARITY_INVERSED;
> >> + state->enabled = (ctrl_data & PTC_EN) ? true : false;
> >> +
> >> + return 0;
> >> +}
> >> +
> >> +static int starfive_pwm_ptc_apply(struct pwm_chip *chip,
> >> + struct pwm_device *dev,
> >> + const struct pwm_state *state)
> >> +{
> >> + struct starfive_pwm_ptc_device *pwm = chip_to_starfive_ptc(chip);
> >> + u32 period_data, duty_data, ctrl_data = 0;
> >> +
> >> + if (state->polarity != PWM_POLARITY_INVERSED)
> >> + return -EINVAL;
> >> +
> >> + period_data = DIV_ROUND_CLOSEST_ULL(state->period * pwm->clk_rate,
> >> + NSEC_PER_SEC);
> >> + duty_data = DIV_ROUND_CLOSEST_ULL(state->duty_cycle * pwm->clk_rate,
> >> + NSEC_PER_SEC);
> >> +
> >> + writel(period_data, REG_PTC_RPTC_LRC(pwm->regs, dev->hwpwm));
> >> + writel(duty_data, REG_PTC_RPTC_HRC(pwm->regs, dev->hwpwm));
> >> + writel(0, REG_PTC_RPTC_CNTR(pwm->regs, dev->hwpwm));
> >> +
> >> + ctrl_data = readl(REG_PTC_RPTC_CTRL(pwm->regs, dev->hwpwm));
> >> + if (state->enabled)
> >> + writel(ctrl_data | PTC_EN | PTC_OE, REG_PTC_RPTC_CTRL(pwm->regs, dev->hwpwm));
> >> + else
> >> + writel(ctrl_data & ~(PTC_EN | PTC_OE), REG_PTC_RPTC_CTRL(pwm->regs, dev->hwpwm));
> >> +
> >> + return 0;
> >> +}
> >> +
> >> +static const struct pwm_ops starfive_pwm_ptc_ops = {
> >> + .get_state = starfive_pwm_ptc_get_state,
> >> + .apply = 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;
> >> + 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 = 3;
> >> +
> >> + pwm->regs = devm_platform_ioremap_resource(pdev, 0);
> >> + if (IS_ERR(pwm->regs))
> >> + return dev_err_probe(dev, PTR_ERR(pwm->regs),
> >> + "Unable to map IO resources\n");
> >> +
> >> + pwm->clk = devm_clk_get_enabled(dev, NULL);
> >> + if (IS_ERR(pwm->clk))
> >> + return dev_err_probe(dev, PTR_ERR(pwm->clk),
> >> + "Unable to get pwm's clock\n");
> >> +
> >> + pwm->rst = devm_reset_control_get_exclusive(dev, NULL);
> >> + if (IS_ERR(pwm->rst))
> >> + return dev_err_probe(dev, PTR_ERR(pwm->rst),
> >> + "Unable to get pwm's reset\n");
> >> +
> >> + ret = reset_control_deassert(pwm->rst);
> >> + if (ret) {
> >> + dev_err(dev, "Failed to enable clock for pwm: %d\n", ret);
> >> + return ret;
> >> + }
> >> +
> >> + pwm->clk_rate = clk_get_rate(pwm->clk);
> >> + if (pwm->clk_rate <= 0) {
> >> + dev_warn(dev, "Failed to get APB clock rate\n");
> >> + return -EINVAL;
> >> + }
> >> +
> >> + ret = devm_pwmchip_add(dev, chip);
> >> + if (ret < 0) {
> >> + dev_err(dev, "Cannot register PTC: %d\n", ret);
> >> + clk_disable_unprepare(pwm->clk);
> >> + reset_control_assert(pwm->rst);
> >> + 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);
> >> +
> >> + reset_control_assert(pwm->rst);
> >> + clk_disable_unprepare(pwm->clk);
> >> +
> >> + return 0;
> >> +}
> >> +
> >> +static const struct of_device_id starfive_pwm_ptc_of_match[] = {
> >> + { .compatible = "starfive,jh7100-pwm" },
> >> + { .compatible = "starfive,jh7110-pwm" },
> >> + { /* sentinel */ }
> >> +};
> >> +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",
> >
> > Here
> >
> >> + .of_match_table = starfive_pwm_ptc_of_match,
> >> + },
> >> +};
> >> +module_platform_driver(starfive_pwm_ptc_driver);
> >> +
> >> +MODULE_AUTHOR("Jieqin Chen");
> >> +MODULE_AUTHOR("Hal Feng <hal.feng@xxxxxxxxxxxxxxxx>");
> >> +MODULE_DESCRIPTION("StarFive PWM PTC driver");
> >
> > ..and here you're also still calling the driver PTC without explaining why.
> >
> >> +MODULE_LICENSE("GPL");
> >> --
> >> 2.34.1
> >>

Next message: Adrian Hunter: "Re: [PATCH 2/6] mmc: sdhci: add __sdhci_execute_tuning() to header"
Previous message: Stefano Garzarella: "[PATCH] vringh: don't use vringh_kiov_advance() in vringh_iov_xfer()"
In reply to: William Qiu: "Re: [PATCH v5 2/4] pwm: starfive: Add PWM driver support"
Next in thread: William Qiu: "Re: [PATCH v5 2/4] pwm: starfive: Add PWM driver support"
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