[PATCH v1 2/4] ARM: PWM: add allwinner sun8i R40/V40/T3 pwm support.
Claudiu Beznea
Claudiu.Beznea at microchip.com
Thu Jan 11 07:33:01 PST 2018
On 11.01.2018 13:32, hao_zhang wrote:
> This patch add allwinner sun8i R40/V40/T3 pwm support.
>
> Signed-off-by: hao_zhang <hao5781286 at gmail.com>
> ---
> drivers/pwm/Kconfig | 10 ++
> drivers/pwm/Makefile | 1 +
> drivers/pwm/pwm-sun8i-r40.c | 394 ++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 405 insertions(+)
> create mode 100644 drivers/pwm/pwm-sun8i-r40.c
>
> diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
> index 763ee50..cde5a70 100644
> --- a/drivers/pwm/Kconfig
> +++ b/drivers/pwm/Kconfig
> @@ -444,6 +444,16 @@ config PWM_SUN4I
> To compile this driver as a module, choose M here: the module
> will be called pwm-sun4i.
>
> +config PWM_SUN8I_R40
> + tristate "Allwinner PWM SUN8I R40 support"
> + depends on ARCH_SUNXI || COMPILE_TEST
> + depends on HAS_IOMEM && COMMON_CLK
> + help
> + Generic PWM framework driver for Allwinner SoCs R40, V40, T3.
> +
> + To compile this driver as a module, choose M here: the module
> + will be called pwm-sun8i-r40.
> +
> config PWM_TEGRA
> tristate "NVIDIA Tegra PWM support"
> depends on ARCH_TEGRA
> diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
> index 0258a74..026a55b 100644
> --- a/drivers/pwm/Makefile
> +++ b/drivers/pwm/Makefile
> @@ -44,6 +44,7 @@ obj-$(CONFIG_PWM_STM32) += pwm-stm32.o
> obj-$(CONFIG_PWM_STM32_LP) += pwm-stm32-lp.o
> obj-$(CONFIG_PWM_STMPE) += pwm-stmpe.o
> obj-$(CONFIG_PWM_SUN4I) += pwm-sun4i.o
> +obj-$(CONFIG_PWM_SUN8I_R40) += pwm-sun8i-r40.o
> obj-$(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-sun8i-r40.c b/drivers/pwm/pwm-sun8i-r40.c
> new file mode 100644
> index 0000000..3d34285
> --- /dev/null
> +++ b/drivers/pwm/pwm-sun8i-r40.c
> @@ -0,0 +1,394 @@
> +#include <linux/bitops.h>
> +#include <linux/clk.h>
> +#include <linux/delay.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>
> +#include <linux/regmap.h>
> +
> +#define PWM_IRQ_ENABLE_REG 0x0000
> +#define PCIE(ch) BIT(ch)
> +
> +#define PWM_IRQ_STATUS_REG 0x0004
> +#define PIS(ch) BIT(ch)
> +
> +#define CAPTURE_IRQ_ENABLE_REG 0x0010
> +#define CFIE(ch) BIT(ch << 1 + 1)
> +#define CRIE(ch) BIT(ch << 1)
> +
> +#define CAPTURE_IRQ_STATUS_REG 0x0014
> +#define CFIS(ch) BIT(ch << 1 + 1)
> +#define CRIS(ch) BIT(ch << 1)
> +
> +#define CLK_CFG_REG(ch) (0x0020 + (ch >> 1) * 4)
> +#define CLK_SRC BIT(7)
> +#define CLK_SRC_BYPASS_SEC BIT(6)
> +#define CLK_SRC_BYPASS_FIR BIT(5)
> +#define CLK_GATING BIT(4)
> +#define CLK_DIV_M GENMASK(3, 0)
> +
> +#define PWM_DZ_CTR_REG(ch) (0x0030 + (ch >> 1) * 4)
> +#define PWM_DZ_INTV GENMASK(15, 8)
> +#define PWM_DZ_EN BIT(0)
> +
> +#define PWM_ENABLE_REG 0x0040
> +#define PWM_EN(ch) BIT(ch)
> +
> +#define CAPTURE_ENABLE_REG 0x0044
> +#define CAP_EN(ch) BIT(ch)
> +
> +#define PWM_CTR_REG(ch) (0x0060 + ch * 0x20)
> +#define PWM_PERIOD_RDY BIT(11)
> +#define PWM_PUL_START BIT(10)
> +#define PWM_MODE BIT(9)
> +#define PWM_ACT_STA BIT(8)
> +#define PWM_PRESCAL_K GENMASK(7, 0)
> +
> +#define PWM_PERIOD_REG(ch) (0x0064 + ch * 0x20)
> +#define PWM_ENTIRE_CYCLE GENMASK(31, 16)
> +#define PWM_ACT_CYCLE GENMASK(15, 0)
> +
> +#define PWM_CNT_REG(ch) (0x0068 + ch * 0x20)
> +#define PWM_CNT_VAL GENMASK(15, 0)
> +
> +#define CAPTURE_CTR_REG(ch) (0x006c + ch * 0x20)
> +#define CAPTURE_CRLF BIT(2)
> +#define CAPTURE_CFLF BIT(1)
> +#define CAPINV BIT(0)
> +
> +#define CAPTURE_RISE_REG(ch) (0x0070 + ch * 0x20)
> +#define CAPTURE_CRLR GENMASK(15, 0)
> +
> +#define CAPTURE_FALL_REG(ch) (0x0074 + ch * 0x20)
> +#define CAPTURE_CFLR GENMASK(15, 0)
> +
> +struct sun8i_pwm_data {
> + bool has_prescaler_bypass;
> + bool has_rdy;
> + unsigned int npwm;
> +};
> +
> +struct sun8i_pwm_chip {
> + struct pwm_chip chip;
> + struct clk *clk;
> + void __iomem *base;
> + spinlock_t ctrl_lock;
> + const struct sun8i_pwm_data *data;
> + struct regmap *regmap;
> +};
> +
> +static const u16 div_m_table[] = {
> + 1,
> + 2,
> + 4,
> + 8,
> + 16,
> + 32,
> + 64,
> + 128,
> + 256
> +};
> +
> +static inline struct sun8i_pwm_chip *to_sun8i_pwm_chip(struct pwm_chip *chip)
> +{
> + return container_of(chip, struct sun8i_pwm_chip, chip);
> +}
> +
> +static u32 sun8i_pwm_read(struct sun8i_pwm_chip *sun8i_pwm,
> + unsigned long offset)
> +{
> + u32 val;
> +
> + regmap_read(sun8i_pwm->regmap, offset, &val);
> +
> + return val;
> +}
> +
> +static inline void sun8i_pwm_set_bit(struct sun8i_pwm_chip *sun8i_pwm,
> + unsigned long reg, u32 bit)
> +{
> + regmap_update_bits(sun8i_pwm->regmap, reg, bit, bit);
> +}
> +
> +static inline void sun8i_pwm_clear_bit(struct sun8i_pwm_chip *sun8i_pwm,
> + unsigned long reg, u32 bit)
> +{
> + regmap_update_bits(sun8i_pwm->regmap, reg, bit, 0);
> +}
> +
> +static inline void sun8i_pwm_set_value(struct sun8i_pwm_chip *sun8i_pwm,
> + unsigned long reg, u32 mask, u32 val)
> +{
> + regmap_update_bits(sun8i_pwm->regmap, reg, mask, val);
> +}
> +
> +static void sun8i_pwm_set_polarity(struct sun8i_pwm_chip *chip, u32 ch,
> + enum pwm_polarity polarity)
> +{
> + if (polarity == PWM_POLARITY_NORMAL)
> + sun8i_pwm_set_bit(chip, PWM_CTR_REG(ch), PWM_ACT_STA);
> + else
> + sun8i_pwm_clear_bit(chip, PWM_CTR_REG(ch), PWM_ACT_STA);
> +}
> +
> +static int sun8i_pwm_config(struct sun8i_pwm_chip *sun8i_pwm, u8 ch,
> + struct pwm_state *state)
> +{
> + u64 clk_rate, clk_div, val;
> + u16 prescaler = 0;
> + u8 id = 0;
> +
> + clk_rate = clk_get_rate(sun8i_pwm->clk);
> +
> + if (clk_rate == 24000000)
> + sun8i_pwm_clear_bit(sun8i_pwm, CLK_CFG_REG(ch), CLK_SRC);
> + else
> + sun8i_pwm_set_bit(sun8i_pwm, CLK_CFG_REG(ch), CLK_SRC);
> +
> + if (sun8i_pwm->data->has_prescaler_bypass) {
> + /* pwm output bypass */
> + if (ch % 2)
> + sun8i_pwm_set_bit(sun8i_pwm, CLK_CFG_REG(ch),
> + CLK_SRC_BYPASS_FIR);
> + else
> + sun8i_pwm_set_bit(sun8i_pwm, CLK_CFG_REG(ch),
> + CLK_SRC_BYPASS_SEC);
> + return 0;
> + }
> +
> + val = state->period * clk_rate;
> + do_div(val, NSEC_PER_SEC);
> + if (val < 1) {
> + dev_err(sun8i_pwm->chip.dev,
> + "period expects a larger value\n");
> + return -EINVAL;
> + }
> +
> + /* calculate and set prescalar, div table, pwn entrie cycle */
> + clk_div = val;
> +
> + while (clk_div > 65535) {
> + prescaler++;
> + clk_div = val;
> + do_div(clk_div, prescaler + 1);
> + do_div(clk_div, div_m_table[id]);
> +
> + if (prescaler == 255) {
> + prescaler = 0;
> + id++;
> + if (id == 9)
> + return -EINVAL;
> + }
> + }
> +
> + sun8i_pwm_set_value(sun8i_pwm, PWM_PERIOD_REG(ch),
> + PWM_ENTIRE_CYCLE, clk_div << 16);
> + sun8i_pwm_set_value(sun8i_pwm, PWM_CTR_REG(ch),
> + PWM_PRESCAL_K, prescaler << 0);
> + sun8i_pwm_set_value(sun8i_pwm, CLK_CFG_REG(ch),
> + CLK_DIV_M, id << 0);
> +
> + /* set duty cycle */
> + val = (prescaler + 1) * div_m_table[id] * clk_div;
> + val = state->period;
> + do_div(val, clk_div);
> + clk_div = state->duty_cycle;
> + do_div(clk_div, val);
> +
> + sun8i_pwm_set_value(sun8i_pwm, PWM_PERIOD_REG(ch),
> + PWM_ACT_CYCLE, clk_div << 0);
> +
> + return 0;
> +}
> +
> +static int sun8i_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
> + struct pwm_state *state)
> +{
> + int ret;
> + struct sun8i_pwm_chip *sun8i_pwm = to_sun8i_pwm_chip(chip);
> + struct pwm_state cstate;
> +
> + pwm_get_state(pwm, &cstate);
> + if (!cstate.enabled) {
> + ret = clk_prepare_enable(sun8i_pwm->clk);
You call clk_prepare_enable() here, under !cstate.enabled condition.
> + if (ret) {
> + dev_err(chip->dev, "failed to enable PWM clock\n");
> + return ret;
> + }
> + }
> +
> + spin_lock(&sun8i_pwm->ctrl_lock);
> +
> + if ((cstate.period != state->period) ||
> + (cstate.duty_cycle != state->duty_cycle)) {
> + ret = sun8i_pwm_config(sun8i_pwm, pwm->hwpwm, state);
> + if (ret) > + clk_disable_unprepare(sun8i_pwm->clk);
You need to call clk_disable_unprepare() only if !cstate.enabled:
if (!cstate.enabled)
clk_disable_unprepare();
> + spin_unlock(&sun8i_pwm->ctrl_lock);
> + dev_err(chip->dev, "failed to config PWM\n");
> + return ret;
> + }
> + }
> +
> + if (state->polarity != cstate.polarity)
> + sun8i_pwm_set_polarity(sun8i_pwm, pwm->hwpwm, state->polarity);
> +
> + if (state->enabled) {
> + sun8i_pwm_set_bit(sun8i_pwm,
> + CLK_CFG_REG(pwm->hwpwm), CLK_GATING);
> +
> + sun8i_pwm_set_bit(sun8i_pwm,
> + PWM_ENABLE_REG, PWM_EN(pwm->hwpwm));
> + } else {
> + sun8i_pwm_clear_bit(sun8i_pwm,
> + CLK_CFG_REG(pwm->hwpwm), CLK_GATING);
> +
> + sun8i_pwm_clear_bit(sun8i_pwm,
> + PWM_ENABLE_REG, PWM_EN(pwm->hwpwm));
> + }
> +
> + spin_unlock(&sun8i_pwm->ctrl_lock);
> +
> + return 0;
> +}
> +
> +static void sun8i_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
> + struct pwm_state *state)
> +{
> + struct sun8i_pwm_chip *sun8i_pwm = to_sun8i_pwm_chip(chip);
> + u64 clk_rate, tmp;
> + u32 val;
> + u16 clk_div, act_cycle;
> + u8 prescal, id;
> +
> + clk_rate = clk_get_rate(sun8i_pwm->clk);
> +
> + val = sun8i_pwm_read(sun8i_pwm, PWM_CTR_REG(pwm->hwpwm));
> + if (PWM_ACT_STA & val)
> + state->polarity = PWM_POLARITY_NORMAL;
> + else
> + state->polarity = PWM_POLARITY_INVERSED;
> +
> + prescal = PWM_PRESCAL_K & val;
> +
> + val = sun8i_pwm_read(sun8i_pwm, PWM_ENABLE_REG);
> + if (PWM_EN(pwm->hwpwm) & val)
> + state->enabled = true;
> + else
> + state->enabled = false;
> +
> + val = sun8i_pwm_read(sun8i_pwm, PWM_PERIOD_REG(pwm->hwpwm));
> + act_cycle = PWM_ACT_CYCLE & val;
> + clk_div = val >> 16;
> +
> + val = sun8i_pwm_read(sun8i_pwm, CLK_CFG_REG(pwm->hwpwm));
> + id = CLK_DIV_M & val;
> +
> + tmp = act_cycle * prescal * div_m_table[id] * NSEC_PER_SEC;
> + state->duty_cycle = DIV_ROUND_CLOSEST_ULL(tmp, clk_rate);
> + tmp = clk_div * prescal * div_m_table[id] * NSEC_PER_SEC;
> + state->period = DIV_ROUND_CLOSEST_ULL(tmp, clk_rate);
> +}
> +
> +static const struct regmap_config sun8i_pwm_regmap_config = {
> + .reg_bits = 32,
> + .reg_stride = 4,
> + .val_bits = 32,
> + .max_register = CAPTURE_FALL_REG(7),
> +};
> +
> +static const struct pwm_ops sun8i_pwm_ops = {
> + .apply = sun8i_pwm_apply,
> + .get_state = sun8i_pwm_get_state,
> + .owner = THIS_MODULE,
> +};
> +
> +static const struct sun8i_pwm_data sun8i_pwm_data_r40 = {
> + .has_prescaler_bypass = false,
> + .has_rdy = true,
> + .npwm = 8,
> +};
> +
> +static const struct of_device_id sun8i_pwm_dt_ids[] = {
> + {
> + .compatible = "allwinner,sun8i-r40-pwm",
> + .data = &sun8i_pwm_data_r40,
> + },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, sun8i_pwm_dt_ids);
> +
> +static int sun8i_pwm_probe(struct platform_device *pdev)
> +{
> + struct sun8i_pwm_chip *pwm;
> + struct resource *res;
> + int ret;
> + const struct of_device_id *match;
> +
> + match = of_match_device(sun8i_pwm_dt_ids, &pdev->dev);
check for !match
> +
> + 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->regmap = devm_regmap_init_mmio(&pdev->dev, pwm->base,
> + &sun8i_pwm_regmap_config);
Check for IS_ERR(pwm->regmap)
> +
> + pwm->clk = devm_clk_get(&pdev->dev, NULL);
> + if (IS_ERR(pwm->clk))
> + return PTR_ERR(pwm->clk);
> +
> + pwm->data = match->data;
> + pwm->chip.dev = &pdev->dev;
> + pwm->chip.ops = &sun8i_pwm_ops;
> + pwm->chip.base = -1;
> + pwm->chip.npwm = pwm->data->npwm;
> + pwm->chip.of_xlate = of_pwm_xlate_with_flags;
> + pwm->chip.of_pwm_n_cells = 3;
> +
> + 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);
> +
> + return 0;
> +}
> +
> +static int sun8i_pwm_remove(struct platform_device *pdev)
> +{
> + struct sun8i_pwm_chip *pwm = platform_get_drvdata(pdev);
> +
> + return pwmchip_remove(&pwm->chip);
> +}
> +
> +static struct platform_driver sun8i_pwm_driver = {
> + .driver = {
> + .name = "sun8i-r40-pwm",
> + .of_match_table = sun8i_pwm_dt_ids,
> + },
> + .probe = sun8i_pwm_probe,
> + .remove = sun8i_pwm_remove,
> +};
> +module_platform_driver(sun8i_pwm_driver);
> +
> +MODULE_ALIAS("platform:sun8i-r40-pwm");
> +MODULE_AUTHOR("Hao Zhang <hao5781286 at gmail.com>");
> +MODULE_DESCRIPTION("Allwinner sun8i-r40 PWM driver");
> +MODULE_LICENSE("GPL v2");
>
More information about the linux-arm-kernel
mailing list