From: Ban Tao <fengzheng...@gmail.com>
The Allwinner R818, A133, R329, V536 and V833 has a new PWM controller
IP compared to the older Allwinner SoCs.
Signed-off-by: Ban Tao <fengzheng...@gmail.com>
---
v1->v2:
1.delete unnecessary code.
2.using a named define for some constants.
3.Add comment in sun50i_pwm_config function.
4.using dev_err_probe() for error handling.
5.disable the clock after pwmchip_remove().
---
v2->v3:
1.fix all emitted warnings when PWM_DEBUG enabled.
2.modify the name of file pwm-sun50i to pwm-sun8i-v536.
3.fix "sun50i_pwm_from_chip" -> "to_sun8i_pwm_chip".
4.delete some unnecessary "compatible".
---
MAINTAINERS | 6 +
drivers/pwm/Kconfig | 11 +
drivers/pwm/Makefile | 1 +
drivers/pwm/pwm-sun8i-v536.c | 401 +++++++++++++++++++++++++++++++++++
4 files changed, 419 insertions(+)
create mode 100644 drivers/pwm/pwm-sun8i-v536.c
diff --git a/MAINTAINERS b/MAINTAINERS
index e73636b75f29..387e187c635c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -737,6 +737,12 @@ L: linux-me...@vger.kernel.org
S: Maintained
F: drivers/staging/media/sunxi/cedrus/
+ALLWINNER PWM DRIVER
+M: Ban Tao <fengzheng...@gmail.com>
+L: linux-...@vger.kernel.org
+S: Maintained
+F: drivers/pwm/pwm-sun8i-v536.c
+
ALPHA PORT
M: Richard Henderson <r...@twiddle.net>
M: Ivan Kokshaysky <i...@jurassic.park.msu.ru>
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 9a4f66ae8070..3418b5b898a9 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -552,6 +552,17 @@ config PWM_SUN4I
To compile this driver as a module, choose M here: the module
will be called pwm-sun4i.
+config PWM_SUN8I_V536
+ tristate "Allwinner SUN8I_V536 PWM support"
+ depends on ARCH_SUNXI || COMPILE_TEST
+ depends on HAS_IOMEM && COMMON_CLK
+ help
+ Enhanced PWM framework driver for Allwinner R818, A133, R329,
+ V536 and V833 SoCs.
+
+ To compile this driver as a module, choose M here: the module
+ will be called pwm-sun8i-v536.
+
config PWM_TEGRA
tristate "NVIDIA Tegra PWM support"
depends on ARCH_TEGRA || COMPILE_TEST
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index 6374d3b1d6f3..380d6b107308 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -51,6 +51,7 @@ 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-$(CONFIG_PWM_SUN8I_V536) += pwm-sun8i-v536.o
obj-$(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-v536.c b/drivers/pwm/pwm-sun8i-v536.c
new file mode 100644
index 000000000000..52101df6bd41
--- /dev/null
+++ b/drivers/pwm/pwm-sun8i-v536.c
@@ -0,0 +1,401 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for Allwinner sun8i-v536 Pulse Width Modulation Controller
+ *
+ * Copyright (C) 2021 Ban Tao <fengzheng...@gmail.com>
+ *
+ *
+ * Limitations:
+ * - When PWM is disabled, the output is driven to inactive.
+ * - If the register is reconfigured while PWM is running,
+ * it does not complete the currently running period.
+ * - If the user input duty is beyond acceptible limits,
+ * -EINVAL is returned.
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/pwm.h>
+#include <linux/clk.h>
+#include <linux/reset.h>
+
+#define PWM_GET_CLK_OFFSET(chan) (0x20 + ((chan >> 1) * 0x4))
+#define PWM_CLK_APB_SCR BIT(7)
+#define PWM_DIV_M 0
+#define PWM_DIV_M_MASK GENMASK(3, PWM_DIV_M)
+
+#define PWM_CLK_REG 0x40
+#define PWM_CLK_GATING BIT(0)
+
+#define PWM_ENABLE_REG 0x80
+#define PWM_EN BIT(0)
+
+#define PWM_CTL_REG(chan) (0x100 + 0x20 * chan)
+#define PWM_ACT_STA BIT(8)
+#define PWM_PRESCAL_K 0
+#define PWM_PRESCAL_K_MASK GENMASK(7, PWM_PRESCAL_K)
+
+#define PWM_PERIOD_REG(chan) (0x104 + 0x20 * chan)
+#define PWM_ENTIRE_CYCLE 16
+#define PWM_ENTIRE_CYCLE_MASK GENMASK(31, PWM_ENTIRE_CYCLE)
+#define PWM_ACT_CYCLE 0
+#define PWM_ACT_CYCLE_MASK GENMASK(15, PWM_ACT_CYCLE)
+
+#define BIT_CH(bit, chan) ((bit) << (chan))
+#define SET_BITS(shift, mask, reg, val) \
+ (((reg) & ~mask) | (val << (shift)))
+
+#define PWM_OSC_CLK 24000000
+#define PWM_PRESCALER_MAX 256
+#define PWM_CLK_DIV_M__MAX 9
+#define PWM_ENTIRE_CYCLE_MAX 65536
+
+struct sun8i_pwm_data {
+ unsigned int npwm;
+};
+
+struct sun8i_pwm_chip {
+ struct pwm_chip chip;
+ struct clk *clk;
+ struct reset_control *rst_clk;
+ void __iomem *base;
+ const struct sun8i_pwm_data *data;
+};
+
+static inline struct sun8i_pwm_chip *to_sun8i_pwm_chip(struct pwm_chip *chip)
+{
+ return container_of(chip, struct sun8i_pwm_chip, chip);
+}
+
+static inline u32 sun8i_pwm_readl(struct sun8i_pwm_chip *chip,
+ unsigned long offset)
+{
+ return readl(chip->base + offset);
+}
+
+static inline void sun8i_pwm_writel(struct sun8i_pwm_chip *chip,
+ u32 val, unsigned long offset)
+{
+ writel(val, chip->base + offset);
+}
+
+static void sun8i_pwm_get_state(struct pwm_chip *chip,
+ struct pwm_device *pwm,
+ struct pwm_state *state)
+{
+ struct sun8i_pwm_chip *pc = to_sun8i_pwm_chip(chip);
+ u64 clk_rate;
+ u32 tmp, entire_cycles, active_cycles;
+ unsigned int prescaler, div_m;
+
+ tmp = sun8i_pwm_readl(pc, PWM_GET_CLK_OFFSET(pwm->hwpwm));
+ if (tmp & PWM_CLK_APB_SCR)
+ clk_rate = clk_get_rate(pc->clk);
+ else
+ clk_rate = PWM_OSC_CLK;
+
+ tmp = sun8i_pwm_readl(pc, PWM_GET_CLK_OFFSET(pwm->hwpwm));
+ div_m = 0x1 << (tmp & PWM_DIV_M_MASK);
+
+ tmp = sun8i_pwm_readl(pc, PWM_CTL_REG(pwm->hwpwm));
+ prescaler = (tmp & PWM_PRESCAL_K_MASK) + 1;
+
+ tmp = sun8i_pwm_readl(pc, PWM_PERIOD_REG(pwm->hwpwm));
+ entire_cycles = (tmp >> PWM_ENTIRE_CYCLE) + 1;
+ active_cycles = (tmp & PWM_ACT_CYCLE_MASK);
+
+ /* (clk / div_m / prescaler) / entire_cycles = NSEC_PER_SEC /
period_ns. */
+ state->period = DIV_ROUND_CLOSEST_ULL(entire_cycles * NSEC_PER_SEC,
+ clk_rate) * div_m * prescaler;
+ /* duty_ns / period_ns = active_cycles / entire_cycles. */
+ state->duty_cycle = DIV_ROUND_CLOSEST_ULL(active_cycles * state->period,
+ entire_cycles);
+
+ /* parsing polarity */
+ tmp = sun8i_pwm_readl(pc, PWM_CTL_REG(pwm->hwpwm));
+ if (tmp & PWM_ACT_STA)
+ state->polarity = PWM_POLARITY_NORMAL;
+ else
+ state->polarity = PWM_POLARITY_INVERSED;
+
+ /* parsing enabled */
+ tmp = sun8i_pwm_readl(pc, PWM_ENABLE_REG);
+ if (tmp & BIT_CH(PWM_EN, pwm->hwpwm))
+ state->enabled = true;
+ else
+ state->enabled = false;
+
+ dev_dbg(chip->dev, "duty_ns=%lld period_ns=%lld polarity=%s
enabled=%s.\n",
+ state->duty_cycle, state->period,
+ state->polarity ? "inversed":"normal",
+ state->enabled ? "true":"false");
+}
+
+static void sun8i_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device
*pwm,
+ enum pwm_polarity polarity)
+{
+ struct sun8i_pwm_chip *pc = to_sun8i_pwm_chip(chip);
+ u32 temp;
+
+ temp = sun8i_pwm_readl(pc, PWM_CTL_REG(pwm->hwpwm));
+
+ if (polarity == PWM_POLARITY_NORMAL)
+ temp |= PWM_ACT_STA;
+ else
+ temp &= ~PWM_ACT_STA;
+
+ sun8i_pwm_writel(pc, temp, PWM_CTL_REG(pwm->hwpwm));
+}
+
+static int sun8i_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+ const struct pwm_state *state)
+{
+ struct sun8i_pwm_chip *pc = to_sun8i_pwm_chip(chip);
+ unsigned long long c;
+ unsigned long entire_cycles, active_cycles;
+ unsigned int div_m, prescaler;
+ u64 duty_ns = state->duty_cycle, period_ns = state->period;
+ u32 config;
+ int ret = 0;
+
+ if (period_ns > 334) {
+ /* if freq < 3M, then select 24M clock */
+ c = PWM_OSC_CLK;
+ config = sun8i_pwm_readl(pc, PWM_GET_CLK_OFFSET(pwm->hwpwm));
+ config &= ~PWM_CLK_APB_SCR;
+ sun8i_pwm_writel(pc, config, PWM_GET_CLK_OFFSET(pwm->hwpwm));
+ } else {
+ /* if freq > 3M, then select APB as clock */
+ c = clk_get_rate(pc->clk);
+ config = sun8i_pwm_readl(pc, PWM_GET_CLK_OFFSET(pwm->hwpwm));
+ config |= PWM_CLK_APB_SCR;
+ sun8i_pwm_writel(pc, config, PWM_GET_CLK_OFFSET(pwm->hwpwm));
+ }
+
+ dev_dbg(chip->dev, "duty_ns=%lld period_ns=%lld c =%llu.\n",
+ duty_ns, period_ns, c);
+
+ /*
+ * (clk / div_m / prescaler) / entire_cycles = NSEC_PER_SEC / period_ns.
+ * So, entire_cycles = clk * period_ns / NSEC_PER_SEC / div_m /
prescaler.
+ */
+ c = c * period_ns;
+ c = DIV_ROUND_CLOSEST_ULL(c, NSEC_PER_SEC);
+ for (div_m = 0; div_m < PWM_CLK_DIV_M__MAX; div_m++) {
+ for (prescaler = 0; prescaler < PWM_PRESCALER_MAX; prescaler++)
{
+ /*
+ * actual prescaler = prescaler(reg value) + 1.
+ * actual div_m = 0x1 << div_m(reg value).
+ */
+ entire_cycles = ((unsigned long)c >> div_m)/(prescaler
+ 1);
+ if (entire_cycles <= PWM_ENTIRE_CYCLE_MAX)
+ goto calc_end;
+ }
+ }
+ ret = -EINVAL;
+ goto exit;
+
+calc_end:
+ /*
+ * duty_ns / period_ns = active_cycles / entire_cycles.
+ * So, active_cycles = entire_cycles * duty_ns / period_ns.
+ */
+ c = (unsigned long long)entire_cycles * duty_ns;
+ c = DIV_ROUND_CLOSEST_ULL(c, period_ns);
+ active_cycles = c;
+ if (entire_cycles == 0)
+ entire_cycles++;
+
+ /* config clk div_m*/
+ config = sun8i_pwm_readl(pc, PWM_GET_CLK_OFFSET(pwm->hwpwm));
+ config = SET_BITS(PWM_DIV_M, PWM_DIV_M_MASK, config, div_m);
+ sun8i_pwm_writel(pc, config, PWM_GET_CLK_OFFSET(pwm->hwpwm));
+
+ /* config prescaler */
+ config = sun8i_pwm_readl(pc, PWM_CTL_REG(pwm->hwpwm));
+ config = SET_BITS(PWM_PRESCAL_K, PWM_PRESCAL_K_MASK, config, prescaler);
+ sun8i_pwm_writel(pc, config, PWM_CTL_REG(pwm->hwpwm));
+
+ /* config active and period cycles */
+ config = sun8i_pwm_readl(pc, PWM_PERIOD_REG(pwm->hwpwm));
+ config = SET_BITS(PWM_ACT_CYCLE, PWM_ACT_CYCLE_MASK, config,
active_cycles);
+ config = SET_BITS(PWM_ENTIRE_CYCLE, PWM_ENTIRE_CYCLE_MASK,
+ config, (entire_cycles - 1));
+ sun8i_pwm_writel(pc, config, PWM_PERIOD_REG(pwm->hwpwm));
+
+ dev_dbg(chip->dev, "active_cycles=%lu entire_cycles=%lu prescaler=%u
div_m=%u\n",
+ active_cycles, entire_cycles, prescaler, div_m);
+
+exit:
+ return ret;
+}
+
+static void sun8i_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm,
+ bool enable)
+{
+ struct sun8i_pwm_chip *pc = to_sun8i_pwm_chip(chip);
+ u32 clk, pwm_en;
+
+ clk = sun8i_pwm_readl(pc, PWM_CLK_REG);
+ pwm_en = sun8i_pwm_readl(pc, PWM_ENABLE_REG);
+
+ if (enable) {
+ clk |= BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
+ sun8i_pwm_writel(pc, clk, PWM_CLK_REG);
+
+ pwm_en |= BIT_CH(PWM_EN, pwm->hwpwm);
+ sun8i_pwm_writel(pc, pwm_en, PWM_ENABLE_REG);
+ } else {
+ pwm_en &= ~BIT_CH(PWM_EN, pwm->hwpwm);
+ sun8i_pwm_writel(pc, pwm_en, PWM_ENABLE_REG);
+
+ clk &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm);
+ sun8i_pwm_writel(pc, clk, PWM_CLK_REG);
+ }
+}
+
+static int sun8i_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ const struct pwm_state *state)
+{
+ struct pwm_state curstate;
+ int ret;
+
+ pwm_get_state(pwm, &curstate);
+
+ ret = sun8i_pwm_config(chip, pwm, state);
+
+ if (state->polarity != curstate.polarity)
+ sun8i_pwm_set_polarity(chip, pwm, state->polarity);
+
+ if (state->enabled != curstate.enabled)
+ sun8i_pwm_enable(chip, pwm, state->enabled);
+
+ return ret;
+}
+
+static const struct pwm_ops sun8i_pwm_ops = {
+ .get_state = sun8i_pwm_get_state,
+ .apply = sun8i_pwm_apply,
+ .owner = THIS_MODULE,
+};
+
+static const struct sun8i_pwm_data sun8i_pwm_data_c9 = {
+ .npwm = 9,
+};
+
+static const struct sun8i_pwm_data sun50i_pwm_data_c16 = {
+ .npwm = 16,
+};
+
+static const struct of_device_id sun8i_pwm_dt_ids[] = {
+ {
+ .compatible = "allwinner,sun8i-v536-pwm",
+ .data = &sun8i_pwm_data_c9,
+ }, {
+ .compatible = "allwinner,sun50i-r818-pwm",
+ .data = &sun50i_pwm_data_c16,
+ }, {
+ /* sentinel */
+ },
+};
+MODULE_DEVICE_TABLE(of, sun8i_pwm_dt_ids);
+
+static int sun8i_pwm_probe(struct platform_device *pdev)
+{
+ struct sun8i_pwm_chip *pc;
+ int ret;
+
+ pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
+ if (!pc)
+ return dev_err_probe(&pdev->dev, -ENOMEM,
+ "memory allocation failed\n");
+
+ pc->data = of_device_get_match_data(&pdev->dev);
+ if (!pc->data)
+ return dev_err_probe(&pdev->dev, -ENODEV,
+ "can't get match data\n");
+
+ pc->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(pc->base))
+ return dev_err_probe(&pdev->dev, PTR_ERR(pc->base),
+ "can't remap pwm resource\n");
+
+ pc->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(pc->clk))
+ return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk),
+ "get clock failed\n");
+
+ pc->rst_clk = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+ if (IS_ERR(pc->rst_clk))
+ return dev_err_probe(&pdev->dev, PTR_ERR(pc->rst_clk),
+ "get reset failed\n");
+
+ /* Deassert reset */
+ ret = reset_control_deassert(pc->rst_clk);
+ if (ret < 0)
+ return dev_err_probe(&pdev->dev, ret,
+ "cannot deassert reset control\n");
+
+ ret = clk_prepare_enable(pc->clk);
+ if (ret) {
+ dev_err(&pdev->dev, "cannot prepare and enable clk %pe\n",
+ ERR_PTR(ret));
+ goto err_clk;
+ }
+
+ pc->chip.dev = &pdev->dev;
+ pc->chip.ops = &sun8i_pwm_ops;
+ pc->chip.npwm = pc->data->npwm;
+ pc->chip.of_xlate = of_pwm_xlate_with_flags;
+ pc->chip.base = -1;
+ pc->chip.of_pwm_n_cells = 3;
+
+ ret = pwmchip_add(&pc->chip);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
+ goto err_pwm_add;
+ }
+
+ platform_set_drvdata(pdev, pc);
+
+ return 0;
+
+err_pwm_add:
+ clk_disable_unprepare(pc->clk);
+err_clk:
+ reset_control_assert(pc->rst_clk);
+
+ return ret;
+}
+
+static int sun8i_pwm_remove(struct platform_device *pdev)
+{
+ struct sun8i_pwm_chip *pc = platform_get_drvdata(pdev);
+ int ret;
+
+ ret = pwmchip_remove(&pc->chip);
+ if (ret)
+ return ret;
+
+ clk_disable_unprepare(pc->clk);
+ reset_control_assert(pc->rst_clk);
+
+ return 0;
+}
+
+static struct platform_driver sun8i_pwm_driver = {
+ .driver = {
+ .name = "sun8i-pwm-v536",
+ .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-v536-pwm");
+MODULE_AUTHOR("Ban Tao <fengzheng...@gmail.com>");
+MODULE_DESCRIPTION("Allwinner sun8i-v536 PWM driver");
+MODULE_LICENSE("GPL v2");
--
2.29.0
