From: Biju Das <biju.das.jz@bp.renesas.com>
The RZ/V2{M, MA} PWM Timer supports the following functions:
* The PWM has 24-bit counters which operate at PWM_CLK (48 MHz).
* The frequency division ratio for internal counter operation is
selectable as PWM_CLK divided by 1, 16, 256, or 2048.
* The period as well as the duty cycle is adjustable.
* The low-level and high-level order of the PWM signals can be
inverted.
* The duty cycle of the PWM signal is selectable in the range from
0 to 100%.
* The minimum resolution is 20.83 ns.
* Three interrupt sources: Rising and falling edges of the PWM signal
and clearing of the counter
* Counter operation and the bus interface are asynchronous and both
can operate independently of the magnitude relationship of the
respective clock periods.
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
---
v6->v7:
* Addressed the build issue reported by the kernel test robot.
* Added include math64.h.
* Reworked rzv2m_pwm_mul_u64_u64_div_u64_roundup to make use of
div64_u64 and to get rid of % while keeping the same formula.
* Added rzv2m_pwm_mul_u64_u64_div_u64_rounddown.
* Replaced / with div64_u64 wherever necessary.
v5->v6:
* Added Fab's Signed-off-by.
* Updated copyright year to 2024.
* Added include of limits.h.
* Added variable max_period to rzv2m_pwm_chip.
* Simplified the calculations by calculating max_period during probe,
based on the numerical limits of the formula and the u64 data type.
* Added rzv2m_pwm_mul_u64_u64_div_u64_roundup.
* Added rzv2m_pwm_prescale_to_shift to fix the calculation of the
frequency divider.
* Improved the calculations and the variable names of
rzv2m_pwm_get_state.
* Improved the calculations of rzv2m_pwm_config.
* Removed .owner from rzv2m_pwm_ops.
* Improved rzv2m_pwm_pm_runtime_resume and renamed its err variable to
ret.
* Removed of_match_ptr.
* Added Fab as module author.
v4->v5:
* Sorted KConfig file
* Sorted Make file
* Updated copyright header 2022->2023.
* Updated limitation section.
* Replaced the variable chip->rzv2m_pwm in rzv2m_pwm_wait_delay()
* Replaced polarity logic as per HW manual dutycycle = Ton/Ton+Toff, so
eventhough native polarity is inverted from period point of view it
is correct.
* Added logic for supporting 0% , 100% and remaining duty cycle.
* On config() replaced
pm_runtime_resume_and_get()->pm_runtime_get_sync()
* Counter is stopped while updating period/polarity to avoid glitches.
* Added error check for clk_prepare_enable()
* Introduced is_ch_enabled variable to cache channel enable status.
* clk_get_rate is called after enabling the clock and
clk_rate_exclusive_get()
* Added comment for delay
* Replaced 1000000000UL->NSEC_PER_SEC.
* Improved error handling in probe().
v3->v4:
* Documented the hardware properties in "Limitations" section
* Dropped the macros F2CYCLE_NSEC, U24_MASK and U24_MAX.
* Added RZV2M_PWMCYC_PERIOD macro for U24_MAX
* Dropped rzv2m_pwm_freq_div variable and started using 1 << (4 * i)
for calculating divider as it is power of 16.
* Reordered the functions to have rzv2m_pwm_config() directly before
rzv2m_pwm_apply().
* Improved the logic for calculating period and duty cycle in config()
* Merged multiple RZV2M_PWMCTR register writes to a single write in
* config()
* replaced pwm_is_enabled()->pwm->state.enabled
* Avoided assigning bit value as enum pwm_polarity instead used enum
* constant.
* Fixed various issues in probe error path.
* Updated the logic for PWM cycle setting register
* A 100% duty cycle is only possible with PWMLOW > PWMCYC. So
restricting PWMCYC values < 0xffffff
* The native polarity of the hardware is inverted (i.e. it starts with
the low part). So switched the inversion bit handling.
v2->v3:
* Added return code for rzv2m_pwm_get_state()
* Added comment in rzv2m_pwm_reset_assert_pm_disable()
v1->v2:
* Replaced
devm_reset_control_get_optional_shared->devm_reset_control_get_shared
drivers/pwm/Kconfig | 11 +
drivers/pwm/Makefile | 1 +
drivers/pwm/pwm-rzv2m.c | 480 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 492 insertions(+)
create mode 100644 drivers/pwm/pwm-rzv2m.c
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 4b956d661755..55d46e6183a2 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -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
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index c5ec9e168ee7..cf5a4a1c3b1a 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -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
diff --git a/drivers/pwm/pwm-rzv2m.c b/drivers/pwm/pwm-rzv2m.c
new file mode 100644
index 000000000000..eb9062293590
--- /dev/null
+++ b/drivers/pwm/pwm-rzv2m.c
@@ -0,0 +1,480 @@
+// 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/math64.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;
+ u64 d = div64_u64(ab, c);
+ u64 e = d * c;
+
+ return d + ((ab - e) ? 1 : 0);
+}
+
+static inline u64 rzv2m_pwm_mul_u64_u64_div_u64_rounddown(u64 a, u64 b, u64 c)
+{
+ return div64_u64(a * b, c);
+}
+
+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 = rzv2m_pwm_mul_u64_u64_div_u64_rounddown(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 = rzv2m_pwm_mul_u64_u64_div_u64_rounddown(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 = rzv2m_pwm_mul_u64_u64_div_u64_rounddown(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 = div64_u64(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");
--
2.34.1
On Mon, Feb 12, 2024 at 09:06:50PM +0000, Fabrizio Castro wrote: > From: Biju Das <biju.das.jz@bp.renesas.com> > > The RZ/V2{M, MA} PWM Timer supports the following functions: > > * The PWM has 24-bit counters which operate at PWM_CLK (48 MHz). > * The frequency division ratio for internal counter operation is > selectable as PWM_CLK divided by 1, 16, 256, or 2048. > * The period as well as the duty cycle is adjustable. > * The low-level and high-level order of the PWM signals can be > inverted. > * The duty cycle of the PWM signal is selectable in the range from > 0 to 100%. > * The minimum resolution is 20.83 ns. > * Three interrupt sources: Rising and falling edges of the PWM signal > and clearing of the counter > * Counter operation and the bus interface are asynchronous and both > can operate independently of the magnitude relationship of the > respective clock periods. > > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com> > Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com> > --- > > v6->v7: > * Addressed the build issue reported by the kernel test robot. > * Added include math64.h. > * Reworked rzv2m_pwm_mul_u64_u64_div_u64_roundup to make use of > div64_u64 and to get rid of % while keeping the same formula. > * Added rzv2m_pwm_mul_u64_u64_div_u64_rounddown. > * Replaced / with div64_u64 wherever necessary. > v5->v6: > * Added Fab's Signed-off-by. > * Updated copyright year to 2024. > * Added include of limits.h. > * Added variable max_period to rzv2m_pwm_chip. > * Simplified the calculations by calculating max_period during probe, > based on the numerical limits of the formula and the u64 data type. > * Added rzv2m_pwm_mul_u64_u64_div_u64_roundup. > * Added rzv2m_pwm_prescale_to_shift to fix the calculation of the > frequency divider. > * Improved the calculations and the variable names of > rzv2m_pwm_get_state. > * Improved the calculations of rzv2m_pwm_config. > * Removed .owner from rzv2m_pwm_ops. > * Improved rzv2m_pwm_pm_runtime_resume and renamed its err variable to > ret. > * Removed of_match_ptr. > * Added Fab as module author. > v4->v5: > * Sorted KConfig file > * Sorted Make file > * Updated copyright header 2022->2023. > * Updated limitation section. > * Replaced the variable chip->rzv2m_pwm in rzv2m_pwm_wait_delay() > * Replaced polarity logic as per HW manual dutycycle = Ton/Ton+Toff, so > eventhough native polarity is inverted from period point of view it > is correct. > * Added logic for supporting 0% , 100% and remaining duty cycle. > * On config() replaced > pm_runtime_resume_and_get()->pm_runtime_get_sync() > * Counter is stopped while updating period/polarity to avoid glitches. > * Added error check for clk_prepare_enable() > * Introduced is_ch_enabled variable to cache channel enable status. > * clk_get_rate is called after enabling the clock and > clk_rate_exclusive_get() > * Added comment for delay > * Replaced 1000000000UL->NSEC_PER_SEC. > * Improved error handling in probe(). > v3->v4: > * Documented the hardware properties in "Limitations" section > * Dropped the macros F2CYCLE_NSEC, U24_MASK and U24_MAX. > * Added RZV2M_PWMCYC_PERIOD macro for U24_MAX > * Dropped rzv2m_pwm_freq_div variable and started using 1 << (4 * i) > for calculating divider as it is power of 16. > * Reordered the functions to have rzv2m_pwm_config() directly before > rzv2m_pwm_apply(). > * Improved the logic for calculating period and duty cycle in config() > * Merged multiple RZV2M_PWMCTR register writes to a single write in > * config() > * replaced pwm_is_enabled()->pwm->state.enabled > * Avoided assigning bit value as enum pwm_polarity instead used enum > * constant. > * Fixed various issues in probe error path. > * Updated the logic for PWM cycle setting register > * A 100% duty cycle is only possible with PWMLOW > PWMCYC. So > restricting PWMCYC values < 0xffffff > * The native polarity of the hardware is inverted (i.e. it starts with > the low part). So switched the inversion bit handling. > v2->v3: > * Added return code for rzv2m_pwm_get_state() > * Added comment in rzv2m_pwm_reset_assert_pm_disable() > v1->v2: > * Replaced > devm_reset_control_get_optional_shared->devm_reset_control_get_shared > > drivers/pwm/Kconfig | 11 + > drivers/pwm/Makefile | 1 + > drivers/pwm/pwm-rzv2m.c | 480 ++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 492 insertions(+) > create mode 100644 drivers/pwm/pwm-rzv2m.c > > diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig > index 4b956d661755..55d46e6183a2 100644 > --- a/drivers/pwm/Kconfig > +++ b/drivers/pwm/Kconfig > @@ -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 > diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile > index c5ec9e168ee7..cf5a4a1c3b1a 100644 > --- a/drivers/pwm/Makefile > +++ b/drivers/pwm/Makefile > @@ -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 > diff --git a/drivers/pwm/pwm-rzv2m.c b/drivers/pwm/pwm-rzv2m.c > new file mode 100644 > index 000000000000..eb9062293590 > --- /dev/null > +++ b/drivers/pwm/pwm-rzv2m.c > @@ -0,0 +1,480 @@ > +// 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. If polarity or period is changed, the hardware has to be stopped, to this yields glitches. > + */ > + > +#include <linux/bitfield.h> > +#include <linux/clk.h> > +#include <linux/delay.h> > +#include <linux/io.h> > +#include <linux/limits.h> > +#include <linux/math64.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; a * b might overflow?! > + u64 d = div64_u64(ab, c); > + u64 e = d * c; > + > + return d + ((ab - e) ? 1 : 0); > +} > + > +static inline u64 rzv2m_pwm_mul_u64_u64_div_u64_rounddown(u64 a, u64 b, u64 c) > +{ > + return div64_u64(a * b, c); ditto. This is the same function as mul_u64_u64_div_u64() isn't it? > +} > + > +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); Giving a shift is cheaper than a multiplication, I suggest to do frequency_divisor = rzv2m_pwm_prescale_to_shift(prescale); and instead of multiply by frequency_divisor, use a left-shift operation. > + 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); The register semantic makes me wonder if each period starts with the low part. In that case the hardware called "normal" what is called inverted in the pwm framework?! > + return pm_runtime_put(chip->dev); If you evaluate the return value of pm_runtime_put() maybe check pm_runtime_get_sync() for symmetry, too? > +} > + > +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 = rzv2m_pwm_mul_u64_u64_div_u64_rounddown(period, > + rzv2m_pwm->rate, > + NSEC_PER_SEC); > + pwm_cyc = pwm_cyc ? pwm_cyc : 1; if pwm_cyc is 0 here, the period is too short to be realized, right? That's an error condition. > + 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 = rzv2m_pwm_mul_u64_u64_div_u64_rounddown(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; I don't understand the relevance of FIELD_FIT(RZV2M_PWMCYC_PERIOD, pwm_cyc - 1). > + > + /* > + * Formula for calculating PWMLOW register: > + * PWMLOW register = PWM cycle * Low pulse width ratio (%) > + */ > + pwm_low = rzv2m_pwm_mul_u64_u64_div_u64_rounddown(duty_cycle, > + rzv2m_pwm->rate, NSEC_PER_SEC * frequency_divisor); > + > + pwm_low = pwm_cyc - pwm_low; Either the old or the new value of pwm_low doesn't match the variable's name. Please add another variable for the wrong one. The compiler should optimize that out and the reader can more easily understand the code. > + 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_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); There is a devm_clk_rate_exclusive_get() in next starting from tomorrow I hope. Using it should simplify the driver. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | https://www.pengutronix.de/ |
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