@@ -524,6 +524,17 @@ config PWM_RZ_MTU3
To compile this driver as a module, choose M here: the module
will be called pwm-rz-mtu3.
+config PWM_RZV2M
+ tristate "Renesas RZ/V2M PWM support"
+ depends on ARCH_R9A09G011 || COMPILE_TEST
+ depends on HAS_IOMEM
+ help
+ This driver exposes the PWM controller found in Renesas
+ RZ/V2M like chips through the PWM API.
+
+ To compile this driver as a module, choose M here: the module
+ will be called pwm-rzv2m.
+
config PWM_SAMSUNG
tristate "Samsung PWM support"
depends on PLAT_SAMSUNG || ARCH_S5PV210 || ARCH_EXYNOS || COMPILE_TEST
@@ -48,6 +48,7 @@ obj-$(CONFIG_PWM_RCAR) += pwm-rcar.o
obj-$(CONFIG_PWM_RENESAS_TPU) += pwm-renesas-tpu.o
obj-$(CONFIG_PWM_ROCKCHIP) += pwm-rockchip.o
obj-$(CONFIG_PWM_RZ_MTU3) += pwm-rz-mtu3.o
+obj-$(CONFIG_PWM_RZV2M) += pwm-rzv2m.o
obj-$(CONFIG_PWM_SAMSUNG) += pwm-samsung.o
obj-$(CONFIG_PWM_SIFIVE) += pwm-sifive.o
obj-$(CONFIG_PWM_SL28CPLD) += pwm-sl28cpld.o
new file mode 100644
@@ -0,0 +1,469 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Renesas RZ/V2M PWM Timer (PWM) driver
+ *
+ * Copyright (C) 2024 Renesas Electronics Corporation
+ *
+ * Hardware manual for this IP can be found here
+ * https://www.renesas.com/in/en/document/mah/rzv2m-users-manual-hardware?language=en
+ *
+ * Limitations:
+ * - Changes to the duty cycle configuration get effective only after the next
+ * period end.
+ * - The duty cycle can be changed only by modifying the PWMLOW register
+ * value and changing the pulse width at low level. The duty cycle becomes
+ * 0% for the low width when the value of the PWMLOW register is 0x0h
+ * and 100% for the low width when the value of the PWMLOW > PWMCYC.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/limits.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/pwm.h>
+#include <linux/reset.h>
+#include <linux/time.h>
+
+#define RZV2M_PWMCTR 0x0
+#define RZV2M_PWMCYC 0x4
+#define RZV2M_PWMLOW 0x8
+#define RZV2M_PWMCNT 0xc
+
+#define RZV2M_PWMCTR_PWMPS GENMASK(17, 16)
+#define RZV2M_PWMCTR_PWMHL BIT(3)
+#define RZV2M_PWMCTR_PWMTM BIT(2)
+#define RZV2M_PWMCTR_PWME BIT(1)
+
+#define RZV2M_PWMCYC_PERIOD GENMASK(23, 0)
+#define RZV2M_PWMLOW_PERIOD GENMASK(23, 0)
+
+struct rzv2m_pwm_chip {
+ u64 max_period;
+ struct pwm_chip chip;
+ void __iomem *mmio;
+ struct reset_control *rstc;
+ struct clk *apb_clk;
+ struct clk *pwm_clk;
+ unsigned long rate;
+ unsigned long delay;
+ unsigned long pwm_cyc;
+ enum pwm_polarity polarity;
+ bool is_ch_enabled;
+};
+
+static inline u64 rzv2m_pwm_mul_u64_u64_div_u64_roundup(u64 a, u64 b, u64 c)
+{
+ u64 ab = a * b;
+
+ return ab / c + (ab % c ? 1 : 0);
+}
+
+static inline struct rzv2m_pwm_chip *to_rzv2m_pwm_chip(struct pwm_chip *chip)
+{
+ return container_of(chip, struct rzv2m_pwm_chip, chip);
+}
+
+static void rzv2m_pwm_wait_delay(struct rzv2m_pwm_chip *rzv2m_pwm)
+{
+ /* delay timer when change the setting register */
+ ndelay(rzv2m_pwm->delay);
+}
+
+static void rzv2m_pwm_write(struct rzv2m_pwm_chip *rzv2m_pwm, u32 reg, u32 data)
+{
+ writel(data, rzv2m_pwm->mmio + reg);
+}
+
+static u32 rzv2m_pwm_read(struct rzv2m_pwm_chip *rzv2m_pwm, u32 reg)
+{
+ return readl(rzv2m_pwm->mmio + reg);
+}
+
+static void rzv2m_pwm_modify(struct rzv2m_pwm_chip *rzv2m_pwm, u32 reg, u32 clr,
+ u32 set)
+{
+ rzv2m_pwm_write(rzv2m_pwm, reg,
+ (rzv2m_pwm_read(rzv2m_pwm, reg) & ~clr) | set);
+}
+
+static u8 rzv2m_pwm_calculate_prescale(struct rzv2m_pwm_chip *rzv2m_pwm,
+ u64 period_cycles)
+{
+ u32 prescaled_period_cycles;
+ u8 prescale;
+
+ prescaled_period_cycles = period_cycles >> 24;
+ if (prescaled_period_cycles >= 256)
+ prescale = 3;
+ else
+ prescale = (fls(prescaled_period_cycles) + 3) / 4;
+
+ return prescale;
+}
+
+static inline int rzv2m_pwm_prescale_to_shift(u8 prescale)
+{
+ return prescale == 3 ? 11 : prescale * 4;
+}
+
+static int rzv2m_pwm_enable(struct rzv2m_pwm_chip *rzv2m_pwm)
+{
+ int rc;
+
+ rc = pm_runtime_resume_and_get(rzv2m_pwm->chip.dev);
+ if (rc)
+ return rc;
+
+ rzv2m_pwm_modify(rzv2m_pwm, RZV2M_PWMCTR, RZV2M_PWMCTR_PWME,
+ RZV2M_PWMCTR_PWME);
+ rzv2m_pwm_wait_delay(rzv2m_pwm);
+ rzv2m_pwm->is_ch_enabled = true;
+
+ return 0;
+}
+
+static void rzv2m_pwm_disable(struct rzv2m_pwm_chip *rzv2m_pwm)
+{
+ rzv2m_pwm_modify(rzv2m_pwm, RZV2M_PWMCTR, RZV2M_PWMCTR_PWME, 0);
+ rzv2m_pwm_wait_delay(rzv2m_pwm);
+ pm_runtime_put_sync(rzv2m_pwm->chip.dev);
+ rzv2m_pwm->is_ch_enabled = false;
+}
+
+static int rzv2m_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
+ struct pwm_state *state)
+{
+ struct rzv2m_pwm_chip *rzv2m_pwm = to_rzv2m_pwm_chip(chip);
+ u16 frequency_divisor;
+ u32 ctr, cyc, low;
+ u8 prescale;
+
+ pm_runtime_get_sync(chip->dev);
+ ctr = rzv2m_pwm_read(rzv2m_pwm, RZV2M_PWMCTR);
+ state->enabled = FIELD_GET(RZV2M_PWMCTR_PWME, ctr);
+ state->polarity = FIELD_GET(RZV2M_PWMCTR_PWMHL, ctr) ?
+ PWM_POLARITY_INVERSED : PWM_POLARITY_NORMAL;
+ prescale = FIELD_GET(RZV2M_PWMCTR_PWMPS, ctr);
+ frequency_divisor = 1 << rzv2m_pwm_prescale_to_shift(prescale);
+
+ cyc = rzv2m_pwm_read(rzv2m_pwm, RZV2M_PWMCYC);
+ state->period = rzv2m_pwm_mul_u64_u64_div_u64_roundup(cyc + 1,
+ NSEC_PER_SEC * frequency_divisor,
+ rzv2m_pwm->rate);
+
+ low = rzv2m_pwm_read(rzv2m_pwm, RZV2M_PWMLOW);
+ state->duty_cycle = rzv2m_pwm_mul_u64_u64_div_u64_roundup(cyc + 1 - low,
+ NSEC_PER_SEC * frequency_divisor,
+ rzv2m_pwm->rate);
+
+ return pm_runtime_put(chip->dev);
+}
+
+static int rzv2m_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+ const struct pwm_state *state)
+{
+ struct rzv2m_pwm_chip *rzv2m_pwm = to_rzv2m_pwm_chip(chip);
+ u64 period = state->period, duty_cycle = state->duty_cycle;
+ u16 frequency_divisor;
+ u64 pwm_cyc, pwm_low;
+ u8 prescale;
+ u32 pwm_ctr;
+
+ /*
+ * Clamp period and duty cycle to their maximum values for our current
+ * configuration rather than letting our calculations overflow.
+ */
+ if (period > rzv2m_pwm->max_period) {
+ period = rzv2m_pwm->max_period;
+ if (duty_cycle > rzv2m_pwm->max_period)
+ duty_cycle = period;
+ }
+
+ /*
+ * Formula for calculating PWM Cycle Setting Register:
+ * PWM cycle = (PWM period(ns) / (PWM_CLK period(ns) × Div ratio)) - 1
+ */
+ pwm_cyc = (period * rzv2m_pwm->rate) / NSEC_PER_SEC;
+ pwm_cyc = pwm_cyc ? pwm_cyc : 1;
+
+ prescale = rzv2m_pwm_calculate_prescale(rzv2m_pwm, pwm_cyc - 1);
+ frequency_divisor = 1 << rzv2m_pwm_prescale_to_shift(prescale);
+ if (frequency_divisor > 1) {
+ pwm_cyc = (period * rzv2m_pwm->rate) /
+ (NSEC_PER_SEC * frequency_divisor);
+ pwm_cyc = pwm_cyc ? pwm_cyc : 1;
+ }
+
+ if (pwm_cyc && !FIELD_FIT(RZV2M_PWMCYC_PERIOD, pwm_cyc - 1))
+ pwm_cyc = RZV2M_PWMCYC_PERIOD + 1;
+
+ /*
+ * Formula for calculating PWMLOW register:
+ * PWMLOW register = PWM cycle * Low pulse width ratio (%)
+ */
+ pwm_low = (duty_cycle * rzv2m_pwm->rate) /
+ (NSEC_PER_SEC * frequency_divisor);
+
+ pwm_low = pwm_cyc - pwm_low;
+ if (!FIELD_FIT(RZV2M_PWMLOW_PERIOD, pwm_low))
+ pwm_low = RZV2M_PWMLOW_PERIOD;
+
+ pwm_cyc--;
+
+ /*
+ * If the PWM channel is disabled, make sure to turn on the clock
+ * before writing the register.
+ */
+ if (!pwm->state.enabled)
+ pm_runtime_get_sync(rzv2m_pwm->chip.dev);
+
+ /*
+ * To change the setting value of the PWM cycle setting register
+ * (PWMm_PWMCYC) or polarity, set the PWME bit of the PWM control
+ * register (PWMm_PWMCTR) to 0b and stop the counter operation.
+ */
+ if (rzv2m_pwm->polarity != state->polarity || rzv2m_pwm->pwm_cyc != pwm_cyc) {
+ rzv2m_pwm_modify(rzv2m_pwm, RZV2M_PWMCTR, RZV2M_PWMCTR_PWME, 0);
+ rzv2m_pwm_wait_delay(rzv2m_pwm);
+ }
+
+ rzv2m_pwm_write(rzv2m_pwm, RZV2M_PWMCYC, pwm_cyc);
+ rzv2m_pwm_write(rzv2m_pwm, RZV2M_PWMLOW, pwm_low);
+
+ pwm_ctr = FIELD_PREP(RZV2M_PWMCTR_PWMPS, prescale);
+ if (state->polarity == PWM_POLARITY_INVERSED)
+ pwm_ctr |= RZV2M_PWMCTR_PWMHL;
+
+ rzv2m_pwm_modify(rzv2m_pwm, RZV2M_PWMCTR, RZV2M_PWMCTR_PWMTM |
+ RZV2M_PWMCTR_PWMPS | RZV2M_PWMCTR_PWMHL, pwm_ctr);
+
+ if (rzv2m_pwm->polarity != state->polarity || rzv2m_pwm->pwm_cyc != pwm_cyc) {
+ rzv2m_pwm->polarity = state->polarity;
+ rzv2m_pwm->pwm_cyc = pwm_cyc;
+ rzv2m_pwm_modify(rzv2m_pwm, RZV2M_PWMCTR, RZV2M_PWMCTR_PWME,
+ RZV2M_PWMCTR_PWME);
+ }
+
+ rzv2m_pwm_wait_delay(rzv2m_pwm);
+
+ /* If the PWM is not enabled, turn the clock off again to save power. */
+ if (!pwm->state.enabled)
+ pm_runtime_put(rzv2m_pwm->chip.dev);
+
+ return 0;
+}
+
+static int rzv2m_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ const struct pwm_state *state)
+{
+ struct rzv2m_pwm_chip *rzv2m_pwm = to_rzv2m_pwm_chip(chip);
+ bool enabled = pwm->state.enabled;
+ int ret;
+
+ if (!state->enabled) {
+ if (enabled)
+ rzv2m_pwm_disable(rzv2m_pwm);
+
+ return 0;
+ }
+
+ ret = rzv2m_pwm_config(chip, pwm, state);
+ if (ret)
+ return ret;
+
+ if (!enabled)
+ ret = rzv2m_pwm_enable(rzv2m_pwm);
+
+ return ret;
+}
+
+static const struct pwm_ops rzv2m_pwm_ops = {
+ .get_state = rzv2m_pwm_get_state,
+ .apply = rzv2m_pwm_apply,
+};
+
+static int rzv2m_pwm_pm_runtime_suspend(struct device *dev)
+{
+ struct rzv2m_pwm_chip *rzv2m_pwm = dev_get_drvdata(dev);
+
+ clk_disable_unprepare(rzv2m_pwm->pwm_clk);
+ clk_disable_unprepare(rzv2m_pwm->apb_clk);
+
+ return 0;
+}
+
+static int rzv2m_pwm_pm_runtime_resume(struct device *dev)
+{
+ struct rzv2m_pwm_chip *rzv2m_pwm = dev_get_drvdata(dev);
+ int ret;
+
+ ret = clk_prepare_enable(rzv2m_pwm->apb_clk);
+ if (ret)
+ return ret;
+
+ ret = clk_prepare_enable(rzv2m_pwm->pwm_clk);
+ if (ret)
+ clk_disable_unprepare(rzv2m_pwm->apb_clk);
+
+ return ret;
+}
+
+static DEFINE_RUNTIME_DEV_PM_OPS(rzv2m_pwm_pm_ops,
+ rzv2m_pwm_pm_runtime_suspend,
+ rzv2m_pwm_pm_runtime_resume, NULL);
+
+static void rzv2m_pwm_reset_assert_pm_disable(void *data)
+{
+ struct rzv2m_pwm_chip *rzv2m_pwm = data;
+
+ /*
+ * The below check is for making balanced PM usage count in probe/remove
+ * eg: boot loader is turning on PWM and probe increments the PM usage
+ * count. Before apply, if there is unbind/remove callback we need to
+ * decrement the PM usage count.
+ */
+ if (rzv2m_pwm->is_ch_enabled)
+ pm_runtime_put(rzv2m_pwm->chip.dev);
+
+ clk_rate_exclusive_put(rzv2m_pwm->pwm_clk);
+ clk_rate_exclusive_put(rzv2m_pwm->apb_clk);
+ pm_runtime_disable(rzv2m_pwm->chip.dev);
+ pm_runtime_set_suspended(rzv2m_pwm->chip.dev);
+ reset_control_assert(rzv2m_pwm->rstc);
+}
+
+static int rzv2m_pwm_probe(struct platform_device *pdev)
+{
+ struct rzv2m_pwm_chip *rzv2m_pwm;
+ unsigned long apb_clk_rate;
+ int ret;
+
+ rzv2m_pwm = devm_kzalloc(&pdev->dev, sizeof(*rzv2m_pwm), GFP_KERNEL);
+ if (!rzv2m_pwm)
+ return -ENOMEM;
+
+ rzv2m_pwm->mmio = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(rzv2m_pwm->mmio))
+ return PTR_ERR(rzv2m_pwm->mmio);
+
+ rzv2m_pwm->apb_clk = devm_clk_get(&pdev->dev, "apb");
+ if (IS_ERR(rzv2m_pwm->apb_clk))
+ return dev_err_probe(&pdev->dev, PTR_ERR(rzv2m_pwm->apb_clk),
+ "cannot get apb clock\n");
+
+ rzv2m_pwm->pwm_clk = devm_clk_get(&pdev->dev, "pwm");
+ if (IS_ERR(rzv2m_pwm->pwm_clk))
+ return dev_err_probe(&pdev->dev, PTR_ERR(rzv2m_pwm->pwm_clk),
+ "cannot get pwm clock\n");
+
+ rzv2m_pwm->rstc = devm_reset_control_get_shared(&pdev->dev, NULL);
+ if (IS_ERR(rzv2m_pwm->rstc))
+ return dev_err_probe(&pdev->dev, PTR_ERR(rzv2m_pwm->rstc),
+ "get reset failed\n");
+
+ platform_set_drvdata(pdev, rzv2m_pwm);
+ ret = reset_control_deassert(rzv2m_pwm->rstc);
+ if (ret) {
+ return dev_err_probe(&pdev->dev, ret,
+ "cannot deassert reset control\n");
+ }
+
+ ret = clk_prepare_enable(rzv2m_pwm->apb_clk);
+ if (ret < 0)
+ goto err_reset;
+
+ ret = clk_prepare_enable(rzv2m_pwm->pwm_clk);
+ if (ret < 0)
+ goto disable_apb_clk;
+
+ clk_rate_exclusive_get(rzv2m_pwm->apb_clk);
+ clk_rate_exclusive_get(rzv2m_pwm->pwm_clk);
+ apb_clk_rate = clk_get_rate(rzv2m_pwm->apb_clk);
+ if (!apb_clk_rate)
+ goto err_rate_put;
+
+ rzv2m_pwm->rate = clk_get_rate(rzv2m_pwm->pwm_clk);
+ if (!rzv2m_pwm->rate)
+ goto err_rate_put;
+ rzv2m_pwm->max_period = U64_MAX / rzv2m_pwm->rate;
+
+ /*
+ * The registers other than the PWM interrupt register (PWMINT) are
+ * always synchronized with PWM_CLK at regular intervals. It takes some
+ * time (Min: 2 × PCLK + 4 × PWM_CLK to Max: 6 × PCLK + 9 × PWM_CLK) for
+ * the value set in the register to be reflected in the PWM circuit
+ * because there is a synchronizer between the register and the PWM
+ * circuit.
+ */
+ rzv2m_pwm->delay = 6 * DIV_ROUND_UP(NSEC_PER_SEC, apb_clk_rate) +
+ 9 * DIV_ROUND_UP(NSEC_PER_SEC, rzv2m_pwm->rate);
+
+ pm_runtime_set_active(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
+
+ /*
+ * We need to keep the clock on, in case the bootloader has enabled the
+ * PWM and is running during probe().
+ */
+ if (!!(rzv2m_pwm_read(rzv2m_pwm, RZV2M_PWMCTR) & RZV2M_PWMCTR_PWME)) {
+ u32 val;
+
+ pm_runtime_get_sync(&pdev->dev);
+ rzv2m_pwm->is_ch_enabled = true;
+ rzv2m_pwm->pwm_cyc = rzv2m_pwm_read(rzv2m_pwm, RZV2M_PWMCYC);
+ val = rzv2m_pwm_read(rzv2m_pwm, RZV2M_PWMCTR);
+ rzv2m_pwm->polarity = FIELD_GET(RZV2M_PWMCTR_PWMHL, val) ?
+ PWM_POLARITY_NORMAL : PWM_POLARITY_INVERSED;
+ }
+
+ rzv2m_pwm->chip.dev = &pdev->dev;
+ ret = devm_add_action_or_reset(&pdev->dev,
+ rzv2m_pwm_reset_assert_pm_disable,
+ rzv2m_pwm);
+ if (ret)
+ return ret;
+
+ rzv2m_pwm->chip.ops = &rzv2m_pwm_ops;
+ rzv2m_pwm->chip.npwm = 1;
+ ret = devm_pwmchip_add(&pdev->dev, &rzv2m_pwm->chip);
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret, "failed to add PWM chip\n");
+
+ pm_runtime_idle(&pdev->dev);
+
+ return 0;
+
+err_rate_put:
+ clk_rate_exclusive_put(rzv2m_pwm->pwm_clk);
+ clk_rate_exclusive_put(rzv2m_pwm->apb_clk);
+ clk_disable_unprepare(rzv2m_pwm->pwm_clk);
+disable_apb_clk:
+ clk_disable_unprepare(rzv2m_pwm->apb_clk);
+err_reset:
+ reset_control_assert(rzv2m_pwm->rstc);
+ return ret;
+}
+
+static const struct of_device_id rzv2m_pwm_of_table[] = {
+ { .compatible = "renesas,rzv2m-pwm", },
+ { /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, rzv2m_pwm_of_table);
+
+static struct platform_driver rzv2m_pwm_driver = {
+ .driver = {
+ .name = "pwm-rzv2m",
+ .pm = pm_ptr(&rzv2m_pwm_pm_ops),
+ .of_match_table = rzv2m_pwm_of_table,
+ },
+ .probe = rzv2m_pwm_probe,
+};
+module_platform_driver(rzv2m_pwm_driver);
+
+MODULE_AUTHOR("Biju Das <biju.das.jz@bp.renesas.com>");
+MODULE_AUTHOR("Fabrizio Castro <fabrizio.castro.jz@renesas.com>");
+MODULE_DESCRIPTION("Renesas RZ/V2M PWM Timer Driver");
+MODULE_LICENSE("GPL");