[PATCHv10 1/2] pwm: Add Allwinner SoC support
Olliver Schinagl
oliver at schinagl.nl
Mon Jan 19 01:51:22 PST 2015
Hey Alexandre,
I'll pull your v10 and start testing that hopefully this week. I've been
using an older version, v8 I think, without any trouble so far.
On 19-01-15 10:21, Chen-Yu Tsai wrote:
> On Thu, Dec 18, 2014 at 5:15 AM, Alexandre Belloni
> <alexandre.belloni at free-electrons.com> wrote:
>> This adds a generic PWM framework driver for the PWM controller
>> found on Allwinner SoCs.
> Hi,
>
> Any news on this series?
>
> ChenYu
>
>> Signed-off-by: Alexandre Belloni <alexandre.belloni at free-electrons.com>
>> Acked-by: Maxime Ripard <maxime.ripard at free-electrons.com>
>> ---
>> drivers/pwm/Kconfig | 10 ++
>> drivers/pwm/Makefile | 1 +
>> drivers/pwm/pwm-sun4i.c | 366 ++++++++++++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 377 insertions(+)
>> create mode 100644 drivers/pwm/pwm-sun4i.c
>>
>> diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
>> index ef2dd2e4754b..07f533d2b5be 100644
>> --- a/drivers/pwm/Kconfig
>> +++ b/drivers/pwm/Kconfig
>> @@ -263,6 +263,16 @@ config PWM_STI
>> To compile this driver as a module, choose M here: the module
>> will be called pwm-sti.
>>
>> +config PWM_SUN4I
>> + tristate "Allwinner PWM support"
>> + depends on ARCH_SUNXI || COMPILE_TEST
>> + depends on HAS_IOMEM && COMMON_CLK
>> + help
>> + Generic PWM framework driver for Allwinner SoCs.
>> +
>> + To compile this driver as a module, choose M here: the module
>> + will be called pwm-sun4i.
>> +
>> config PWM_TEGRA
>> tristate "NVIDIA Tegra PWM support"
>> depends on ARCH_TEGRA
>> diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
>> index c458606c3755..d607804deea1 100644
>> --- a/drivers/pwm/Makefile
>> +++ b/drivers/pwm/Makefile
>> @@ -24,6 +24,7 @@ obj-$(CONFIG_PWM_ROCKCHIP) += pwm-rockchip.o
>> obj-$(CONFIG_PWM_SAMSUNG) += pwm-samsung.o
>> obj-$(CONFIG_PWM_SPEAR) += pwm-spear.o
>> obj-$(CONFIG_PWM_STI) += pwm-sti.o
>> +obj-$(CONFIG_PWM_SUN4I) += pwm-sun4i.o
>> obj-$(CONFIG_PWM_TEGRA) += pwm-tegra.o
>> obj-$(CONFIG_PWM_TIECAP) += pwm-tiecap.o
>> obj-$(CONFIG_PWM_TIEHRPWM) += pwm-tiehrpwm.o
>> diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c
>> new file mode 100644
>> index 000000000000..cd9dde563018
>> --- /dev/null
>> +++ b/drivers/pwm/pwm-sun4i.c
>> @@ -0,0 +1,366 @@
>> +/*
>> + * Driver for Allwinner sun4i Pulse Width Modulation Controller
>> + *
>> + * Copyright (C) 2014 Alexandre Belloni <alexandre.belloni at free-electrons.com>
>> + *
>> + * Licensed under GPLv2.
>> + */
>> +
>> +#include <linux/bitops.h>
>> +#include <linux/clk.h>
>> +#include <linux/err.h>
>> +#include <linux/io.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/of_device.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/pwm.h>
>> +#include <linux/slab.h>
>> +#include <linux/spinlock.h>
>> +#include <linux/time.h>
>> +
>> +#define PWM_CTRL_REG 0x0
>> +
>> +#define PWM_CH_PRD_BASE 0x4
>> +#define PWM_CH_PRD_OFFSET 0x4
>> +#define PWM_CH_PRD(ch) (PWM_CH_PRD_BASE + PWM_CH_PRD_OFFSET * (ch))
>> +
>> +#define PWMCH_OFFSET 15
>> +#define PWM_PRESCAL_MASK GENMASK(3, 0)
>> +#define PWM_PRESCAL_OFF 0
>> +#define PWM_EN BIT(4)
>> +#define PWM_ACT_STATE BIT(5)
>> +#define PWM_CLK_GATING BIT(6)
>> +#define PWM_MODE BIT(7)
>> +#define PWM_PULSE BIT(8)
>> +#define PWM_BYPASS BIT(9)
>> +
>> +#define PWM_RDY_BASE 28
>> +#define PWM_RDY_OFFSET 1
>> +#define PWM_RDY(ch) BIT(PWM_RDY_BASE + PWM_RDY_OFFSET * (ch))
>> +
>> +#define PWM_PRD(prd) (((prd) - 1) << 16)
>> +#define PWM_PRD_MASK GENMASK(15, 0)
>> +
>> +#define PWM_DTY_MASK GENMASK(15, 0)
>> +
>> +#define BIT_CH(bit, chan) ((bit) << ((chan) * PWMCH_OFFSET))
>> +
>> +static const u32 prescaler_table[] = {
>> + 120,
>> + 180,
>> + 240,
>> + 360,
>> + 480,
>> + 0,
>> + 0,
>> + 0,
>> + 12000,
>> + 24000,
>> + 36000,
>> + 48000,
>> + 72000,
>> + 0,
>> + 0,
>> + 0, /* Actually 1 but tested separately */
>> +};
>> +
>> +struct sun4i_pwm_data {
>> + bool has_prescaler_bypass;
>> + bool has_rdy;
>> +};
>> +
>> +struct sun4i_pwm_chip {
>> + struct pwm_chip chip;
>> + struct clk *clk;
>> + void __iomem *base;
>> + spinlock_t ctrl_lock;
>> + const struct sun4i_pwm_data *data;
>> +};
>> +
>> +static inline struct sun4i_pwm_chip *to_sun4i_pwm_chip(struct pwm_chip *chip)
>> +{
>> + return container_of(chip, struct sun4i_pwm_chip, chip);
>> +}
>> +
>> +static inline u32 sun4i_pwm_readl(struct sun4i_pwm_chip *chip,
>> + unsigned long offset)
>> +{
>> + return readl(chip->base + offset);
>> +}
>> +
>> +static inline void sun4i_pwm_writel(struct sun4i_pwm_chip *chip,
>> + u32 val, unsigned long offset)
>> +{
>> + writel(val, chip->base + offset);
>> +}
>> +
>> +static int sun4i_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
>> + int duty_ns, int period_ns)
>> +{
>> + struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip);
>> + u32 prd, dty, val, clk_gate;
>> + u64 clk_rate, div = 0;
>> + unsigned int prescaler = 0;
>> + int err;
>> +
>> + clk_rate = clk_get_rate(sun4i_pwm->clk);
>> +
>> + if (sun4i_pwm->data->has_prescaler_bypass) {
>> + /* First, test without any prescaler when available */
>> + prescaler = PWM_PRESCAL_MASK;
>> + /*
>> + * When not using any prescaler, the clock period in nanoseconds
>> + * is not an integer so round it half up instead of
>> + * truncating to get less surprising values.
>> + */
>> + div = clk_rate * period_ns + NSEC_PER_SEC/2;
>> + do_div(div, NSEC_PER_SEC);
>> + if (div - 1 > PWM_PRD_MASK)
>> + prescaler = 0;
>> + }
>> +
>> + if (prescaler == 0) {
>> + /* Go up from the first divider */
>> + for (prescaler = 0; prescaler < PWM_PRESCAL_MASK; prescaler++) {
>> + if (!prescaler_table[prescaler])
>> + continue;
>> + div = clk_rate;
>> + do_div(div, prescaler_table[prescaler]);
>> + div = div * period_ns;
>> + do_div(div, NSEC_PER_SEC);
>> + if (div - 1 <= PWM_PRD_MASK)
>> + break;
>> + }
>> +
>> + if (div - 1 > PWM_PRD_MASK) {
>> + dev_err(chip->dev, "period exceeds the maximum value\n");
>> + return -EINVAL;
>> + }
>> + }
>> +
>> + prd = div;
>> + div *= duty_ns;
>> + do_div(div, period_ns);
>> + dty = div;
>> +
>> + err = clk_prepare_enable(sun4i_pwm->clk);
>> + if (err) {
>> + dev_err(chip->dev, "failed to enable PWM clock\n");
>> + return err;
>> + }
>> +
>> + spin_lock(&sun4i_pwm->ctrl_lock);
>> + val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
>> +
>> + if (sun4i_pwm->data->has_rdy && (val & PWM_RDY(pwm->hwpwm))) {
>> + spin_unlock(&sun4i_pwm->ctrl_lock);
>> + clk_disable_unprepare(sun4i_pwm->clk);
>> + return -EBUSY;
>> + }
>> +
>> + clk_gate = val & BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
>> + if (clk_gate) {
>> + val &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
>> + sun4i_pwm_writel(sun4i_pwm, val, PWM_CTRL_REG);
>> + }
>> +
>> + val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
>> + val &= ~BIT_CH(PWM_PRESCAL_MASK, pwm->hwpwm);
>> + val |= BIT_CH(prescaler, pwm->hwpwm);
>> + sun4i_pwm_writel(sun4i_pwm, val, PWM_CTRL_REG);
>> +
>> + val = (dty & PWM_DTY_MASK) | PWM_PRD(prd);
>> + sun4i_pwm_writel(sun4i_pwm, val, PWM_CH_PRD(pwm->hwpwm));
>> +
>> + if (clk_gate) {
>> + val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
>> + val |= clk_gate;
>> + sun4i_pwm_writel(sun4i_pwm, val, PWM_CTRL_REG);
>> + }
>> +
>> + spin_unlock(&sun4i_pwm->ctrl_lock);
>> + clk_disable_unprepare(sun4i_pwm->clk);
>> +
>> + return 0;
>> +}
>> +
>> +static int sun4i_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
>> + enum pwm_polarity polarity)
>> +{
>> + struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip);
>> + u32 val;
>> + int ret;
>> +
>> + ret = clk_prepare_enable(sun4i_pwm->clk);
>> + if (ret) {
>> + dev_err(chip->dev, "failed to enable PWM clock\n");
>> + return ret;
>> + }
>> +
>> + spin_lock(&sun4i_pwm->ctrl_lock);
>> + val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
>> +
>> + if (polarity != PWM_POLARITY_NORMAL)
>> + val &= ~BIT_CH(PWM_ACT_STATE, pwm->hwpwm);
>> + else
>> + val |= BIT_CH(PWM_ACT_STATE, pwm->hwpwm);
>> +
>> + sun4i_pwm_writel(sun4i_pwm, val, PWM_CTRL_REG);
>> +
>> + spin_unlock(&sun4i_pwm->ctrl_lock);
>> + clk_disable_unprepare(sun4i_pwm->clk);
>> +
>> + return 0;
>> +}
>> +
>> +static int sun4i_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
>> +{
>> + struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip);
>> + u32 val;
>> + int ret;
>> +
>> + ret = clk_prepare_enable(sun4i_pwm->clk);
>> + if (ret) {
>> + dev_err(chip->dev, "failed to enable PWM clock\n");
>> + return ret;
>> + }
>> +
>> + spin_lock(&sun4i_pwm->ctrl_lock);
>> + val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
>> + val |= BIT_CH(PWM_EN, pwm->hwpwm);
>> + val |= BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
>> + sun4i_pwm_writel(sun4i_pwm, val, PWM_CTRL_REG);
>> + spin_unlock(&sun4i_pwm->ctrl_lock);
>> +
>> + return 0;
>> +}
>> +
>> +static void sun4i_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
>> +{
>> + struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip);
>> + u32 val;
>> +
>> + spin_lock(&sun4i_pwm->ctrl_lock);
>> + val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
>> + val &= ~BIT_CH(PWM_EN, pwm->hwpwm);
>> + val &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
>> + sun4i_pwm_writel(sun4i_pwm, val, PWM_CTRL_REG);
>> + spin_unlock(&sun4i_pwm->ctrl_lock);
>> +
>> + clk_disable_unprepare(sun4i_pwm->clk);
>> +}
>> +
>> +static const struct pwm_ops sun4i_pwm_ops = {
>> + .config = sun4i_pwm_config,
>> + .set_polarity = sun4i_pwm_set_polarity,
>> + .enable = sun4i_pwm_enable,
>> + .disable = sun4i_pwm_disable,
>> + .owner = THIS_MODULE,
>> +};
>> +
>> +static const struct sun4i_pwm_data sun4i_pwm_data_a10 = {
>> + .has_prescaler_bypass = false,
>> + .has_rdy = false,
>> +};
>> +
>> +static const struct sun4i_pwm_data sun4i_pwm_data_a20 = {
>> + .has_prescaler_bypass = true,
>> + .has_rdy = true,
>> +};
>> +
>> +static const struct of_device_id sun4i_pwm_dt_ids[] = {
>> + {
>> + .compatible = "allwinner,sun4i-a10-pwm",
>> + .data = &sun4i_pwm_data_a10,
>> + }, {
>> + .compatible = "allwinner,sun7i-a20-pwm",
>> + .data = &sun4i_pwm_data_a20,
>> + }, {
>> + /* sentinel */
>> + },
>> +};
>> +MODULE_DEVICE_TABLE(of, sun4i_pwm_dt_ids);
>> +
>> +static int sun4i_pwm_probe(struct platform_device *pdev)
>> +{
>> + struct sun4i_pwm_chip *pwm;
>> + struct resource *res;
>> + u32 val;
>> + int i, ret;
>> + const struct of_device_id *match;
>> +
>> + match = of_match_device(sun4i_pwm_dt_ids, &pdev->dev);
>> +
>> + pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
>> + if (!pwm)
>> + return -ENOMEM;
>> +
>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + pwm->base = devm_ioremap_resource(&pdev->dev, res);
>> + if (IS_ERR(pwm->base))
>> + return PTR_ERR(pwm->base);
>> +
>> + pwm->clk = devm_clk_get(&pdev->dev, NULL);
>> + if (IS_ERR(pwm->clk))
>> + return PTR_ERR(pwm->clk);
>> +
>> + pwm->chip.dev = &pdev->dev;
>> + pwm->chip.ops = &sun4i_pwm_ops;
>> + pwm->chip.base = -1;
>> + pwm->chip.npwm = 2;
>> + pwm->chip.can_sleep = true;
>> + pwm->chip.of_xlate = of_pwm_xlate_with_flags;
>> + pwm->chip.of_pwm_n_cells = 3;
>> + pwm->data = match->data;
>> +
>> + spin_lock_init(&pwm->ctrl_lock);
>> +
>> + ret = pwmchip_add(&pwm->chip);
>> + if (ret < 0) {
>> + dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
>> + return ret;
>> + }
>> +
>> + platform_set_drvdata(pdev, pwm);
>> +
>> + ret = clk_prepare_enable(pwm->clk);
>> + if (ret) {
>> + dev_err(&pdev->dev, "failed to enable PWM clock\n");
>> + goto clk_error;
>> + }
>> +
>> + val = sun4i_pwm_readl(pwm, PWM_CTRL_REG);
>> + for (i = 0; i < pwm->chip.npwm; i++)
>> + if (!(val & BIT_CH(PWM_ACT_STATE, i)))
>> + pwm->chip.pwms[i].polarity = PWM_POLARITY_INVERSED;
>> + clk_disable_unprepare(pwm->clk);
>> +
>> + return 0;
>> +
>> +clk_error:
>> + pwmchip_remove(&pwm->chip);
>> + return ret;
>> +}
>> +
>> +static int sun4i_pwm_remove(struct platform_device *pdev)
>> +{
>> + struct sun4i_pwm_chip *pwm = platform_get_drvdata(pdev);
>> +
>> + return pwmchip_remove(&pwm->chip);
>> +}
>> +
>> +static struct platform_driver sun4i_pwm_driver = {
>> + .driver = {
>> + .name = "sun4i-pwm",
>> + .of_match_table = sun4i_pwm_dt_ids,
>> + },
>> + .probe = sun4i_pwm_probe,
>> + .remove = sun4i_pwm_remove,
>> +};
>> +module_platform_driver(sun4i_pwm_driver);
>> +
>> +MODULE_ALIAS("platform:sun4i-pwm");
>> +MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni at free-electrons.com>");
>> +MODULE_DESCRIPTION("Allwinner sun4i PWM driver");
>> +MODULE_LICENSE("GPL v2");
>> --
>> 2.1.0
>>
>>
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