* [PATCH v4 2/2] pwm: add support for NXPs high-side switch MC33XS2410
2024-06-07 12:18 [PATCH v4 0/2] pwm: add support for NXPs high-side switch MC33XS2410 Dimitri Fedrau
2024-06-07 12:18 ` [PATCH v4 1/2] dt-bindings: pwm: add support for MC33XS2410 Dimitri Fedrau
@ 2024-06-07 12:18 ` Dimitri Fedrau
1 sibling, 0 replies; 3+ messages in thread
From: Dimitri Fedrau @ 2024-06-07 12:18 UTC (permalink / raw)
Cc: Dimitri Fedrau, Uwe Kleine-König, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, linux-pwm, devicetree,
linux-kernel
The MC33XS2410 is a four channel high-side switch. Featuring advanced
monitoring and control function, the device is operational from 3.0 V to
60 V. The device is controlled by SPI port for configuration.
Signed-off-by: Dimitri Fedrau <dima.fedrau@gmail.com>
---
drivers/pwm/Kconfig | 12 ++
drivers/pwm/Makefile | 1 +
drivers/pwm/pwm-mc33xs2410.c | 408 +++++++++++++++++++++++++++++++++++
3 files changed, 421 insertions(+)
create mode 100644 drivers/pwm/pwm-mc33xs2410.c
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 1dd7921194f5..1e873a19a1cf 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -380,6 +380,18 @@ config PWM_LPSS_PLATFORM
To compile this driver as a module, choose M here: the module
will be called pwm-lpss-platform.
+config PWM_MC33XS2410
+ tristate "MC33XS2410 PWM support"
+ depends on OF
+ depends on SPI
+ help
+ NXP MC33XS2410 high-side switch driver. The MC33XS2410 is a four
+ channel high-side switch. The device is operational from 3.0 V
+ to 60 V. The device is controlled by SPI port for configuration.
+
+ To compile this driver as a module, choose M here: the module
+ will be called pwm-mc33xs2410.
+
config PWM_MESON
tristate "Amlogic Meson PWM driver"
depends on ARCH_MESON || COMPILE_TEST
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index 90913519f11a..b9b202f7fe7e 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -33,6 +33,7 @@ obj-$(CONFIG_PWM_LPC32XX) += pwm-lpc32xx.o
obj-$(CONFIG_PWM_LPSS) += pwm-lpss.o
obj-$(CONFIG_PWM_LPSS_PCI) += pwm-lpss-pci.o
obj-$(CONFIG_PWM_LPSS_PLATFORM) += pwm-lpss-platform.o
+obj-$(CONFIG_PWM_MC33XS2410) += pwm-mc33xs2410.o
obj-$(CONFIG_PWM_MESON) += pwm-meson.o
obj-$(CONFIG_PWM_MEDIATEK) += pwm-mediatek.o
obj-$(CONFIG_PWM_MICROCHIP_CORE) += pwm-microchip-core.o
diff --git a/drivers/pwm/pwm-mc33xs2410.c b/drivers/pwm/pwm-mc33xs2410.c
new file mode 100644
index 000000000000..9ac4b5a2161b
--- /dev/null
+++ b/drivers/pwm/pwm-mc33xs2410.c
@@ -0,0 +1,408 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2024 Liebherr-Electronics and Drives GmbH
+ *
+ * Limitations:
+ * - Supports frequencies between 0.5Hz and 2048Hz with following steps:
+ * - 0.5 Hz steps from 0.5 Hz to 32 Hz
+ * - 2 Hz steps from 2 Hz to 128 Hz
+ * - 8 Hz steps from 8 Hz to 512 Hz
+ * - 32 Hz steps from 32 Hz to 2048 Hz
+ * - Cannot generate a 0 % duty cycle.
+ * - Always produces low output if disabled.
+ * - Configuration isn't atomic. When changing polarity, duty cycle or period
+ * the data is taken immediately, counters not being affected, resulting in a
+ * behavior of the output pin that is neither the old nor the new state,
+ * rather something in between.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/math64.h>
+#include <linux/minmax.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pwm.h>
+
+#include <asm/unaligned.h>
+
+#include <linux/spi/spi.h>
+
+#define MC33XS2410_GLB_CTRL 0x00
+#define MC33XS2410_GLB_CTRL_MODE_MASK GENMASK(7, 6)
+#define MC33XS2410_GLB_CTRL_NORMAL_MODE BIT(6)
+#define MC33XS2410_PWM_CTRL1 0x05
+#define MC33XS2410_PWM_CTRL1_POL_INV(x) BIT(x)
+#define MC33XS2410_PWM_CTRL3 0x07
+/* x in { 0 ... 3 } */
+#define MC33XS2410_PWM_CTRL3_EN(x) BIT(4 + (x))
+#define MC33XS2410_PWM_FREQ1 0x08
+/* x in { 1 ... 4 } */
+#define MC33XS2410_PWM_FREQ(x) (MC33XS2410_PWM_FREQ1 + (x - 1))
+#define MC33XS2410_PWM_FREQ_STEP_MASK GENMASK(7, 6)
+#define MC33XS2410_PWM_FREQ_COUNT_MASK GENMASK(5, 0)
+#define MC33XS2410_PWM_DC1 0x0c
+/* x in { 1 ... 4 } */
+#define MC33XS2410_PWM_DC(x) (MC33XS2410_PWM_DC1 + (x - 1))
+#define MC33XS2410_WDT 0x14
+
+#define MC33XS2410_WR BIT(7)
+#define MC33XS2410_RD_CTRL BIT(7)
+#define MC33XS2410_RD_DATA_MASK GENMASK(13, 0)
+
+#define MC33XS2410_MIN_PERIOD_STEP0 31250000
+#define MC33XS2410_MAX_PERIOD_STEP0 2000000000
+/* x in { 0 ... 3 } */
+#define MC33XS2410_MIN_PERIOD_STEP(x) (MC33XS2410_MIN_PERIOD_STEP0 >> (2 * x))
+/* x in { 0 ... 3 } */
+#define MC33XS2410_MAX_PERIOD_STEP(x) (MC33XS2410_MAX_PERIOD_STEP0 >> (2 * x))
+
+#define MC33XS2410_MAX_TRANSFERS 5
+#define MC33XS2410_WORD_LEN 2
+
+struct mc33xs2410_pwm {
+ struct spi_device *spi;
+};
+
+static
+inline struct mc33xs2410_pwm *to_pwm_mc33xs2410_chip(struct pwm_chip *chip)
+{
+ return pwmchip_get_drvdata(chip);
+}
+
+static int mc33xs2410_xfer_regs(struct spi_device *spi, bool read, u8 *reg,
+ u16 *val, bool *ctrl, int len)
+{
+ struct spi_transfer t[MC33XS2410_MAX_TRANSFERS] = { { 0 } };
+ u8 tx[MC33XS2410_MAX_TRANSFERS * MC33XS2410_WORD_LEN];
+ u8 rx[MC33XS2410_MAX_TRANSFERS * MC33XS2410_WORD_LEN];
+ int i, ret, reg_i, val_i;
+
+ if (!len)
+ return 0;
+
+ if (read)
+ len++;
+
+ if (len > MC33XS2410_MAX_TRANSFERS)
+ return -EINVAL;
+
+ for (i = 0; i < len; i++) {
+ reg_i = i * MC33XS2410_WORD_LEN;
+ val_i = reg_i + 1;
+ if (read) {
+ if (i < len - 1) {
+ tx[reg_i] = reg[i];
+ tx[val_i] = ctrl[i] ? MC33XS2410_RD_CTRL : 0;
+ t[i].tx_buf = &tx[reg_i];
+ }
+
+ if (i > 0)
+ t[i].rx_buf = &rx[reg_i - MC33XS2410_WORD_LEN];
+ } else {
+ tx[reg_i] = reg[i] | MC33XS2410_WR;
+ tx[val_i] = val[i];
+ t[i].tx_buf = &tx[reg_i];
+ }
+
+ t[i].len = MC33XS2410_WORD_LEN;
+ t[i].cs_change = 1;
+ }
+
+ t[len - 1].cs_change = 0;
+
+ ret = spi_sync_transfer(spi, &t[0], len);
+ if (ret < 0)
+ return ret;
+
+ if (read) {
+ for (i = 0; i < len - 1; i++) {
+ reg_i = i * MC33XS2410_WORD_LEN;
+ val[i] = FIELD_GET(MC33XS2410_RD_DATA_MASK,
+ get_unaligned_be16(&rx[reg_i]));
+ }
+ }
+
+ return 0;
+}
+
+static
+int mc33xs2410_write_regs(struct spi_device *spi, u8 *reg, u16 *val, int len)
+{
+
+ return mc33xs2410_xfer_regs(spi, false, reg, val, NULL, len);
+}
+
+static int mc33xs2410_read_regs(struct spi_device *spi, u8 *reg, bool *ctrl,
+ u16 *val, u8 len)
+{
+ return mc33xs2410_xfer_regs(spi, true, reg, val, ctrl, len);
+}
+
+
+static int mc33xs2410_write_reg(struct spi_device *spi, u8 reg, u16 val)
+{
+ return mc33xs2410_write_regs(spi, ®, &val, 1);
+}
+
+static
+int mc33xs2410_read_reg(struct spi_device *spi, u8 reg, u16 *val, bool ctrl)
+{
+ return mc33xs2410_read_regs(spi, ®, &ctrl, val, 1);
+}
+
+static int mc33xs2410_read_reg_ctrl(struct spi_device *spi, u8 reg, u16 *val)
+{
+ return mc33xs2410_read_reg(spi, reg, val, true);
+}
+
+static
+int mc33xs2410_modify_reg(struct spi_device *spi, u8 reg, u16 mask, u16 val)
+{
+ u16 tmp;
+ int ret;
+
+ ret = mc33xs2410_read_reg_ctrl(spi, reg, &tmp);
+ if (ret < 0)
+ return ret;
+
+ tmp &= ~mask;
+ tmp |= val & mask;
+
+ return mc33xs2410_write_reg(spi, reg, tmp);
+}
+
+static u8 mc33xs2410_pwm_get_freq(u64 period)
+{
+ u8 step, count;
+
+ /*
+ * Check if period is within the limits of each of the four frequency
+ * ranges, starting with the highest frequency(lowest period). Higher
+ * frequencies are represented with better resolution by the device.
+ * Therefore favor frequency range with the better resolution to
+ * minimize error introduced by the frequency steps.
+ */
+
+ switch (period) {
+ case MC33XS2410_MIN_PERIOD_STEP(3) + 1 ... MC33XS2410_MAX_PERIOD_STEP(3):
+ step = 3;
+ break;
+ case MC33XS2410_MAX_PERIOD_STEP(3) + 1 ... MC33XS2410_MAX_PERIOD_STEP(2):
+ step = 2;
+ break;
+ case MC33XS2410_MAX_PERIOD_STEP(2) + 1 ... MC33XS2410_MAX_PERIOD_STEP(1):
+ step = 1;
+ break;
+ case MC33XS2410_MAX_PERIOD_STEP(1) + 1 ... MC33XS2410_MAX_PERIOD_STEP(0):
+ step = 0;
+ break;
+ }
+
+ count = DIV_ROUND_UP((u32)MC33XS2410_MAX_PERIOD_STEP(step), (u32)period);
+ return FIELD_PREP(MC33XS2410_PWM_FREQ_STEP_MASK, step) |
+ FIELD_PREP(MC33XS2410_PWM_FREQ_COUNT_MASK, count - 1);
+}
+
+static u64 mc33xs2410_pwm_get_period(u8 reg)
+{
+ u32 freq, code, steps;
+
+ /*
+ * steps:
+ * - 0 = 0.5Hz
+ * - 1 = 2Hz
+ * - 2 = 8Hz
+ * - 3 = 32Hz
+ * frequency = (code + 1) x steps.
+ *
+ * To avoid division in case steps value is zero we scale the steps
+ * value for now by two and keep it in mind when calculating the period
+ * that we have doubled the frequency.
+ */
+ steps = 1 << (FIELD_GET(MC33XS2410_PWM_FREQ_STEP_MASK, reg) * 2);
+ code = FIELD_GET(MC33XS2410_PWM_FREQ_COUNT_MASK, reg);
+ freq = (code + 1) * steps;
+
+ /* Convert frequency to period, considering the doubled frequency. */
+ return DIV_ROUND_UP((u32)(2 * NSEC_PER_SEC), freq);
+}
+
+static int mc33xs2410_pwm_get_relative_duty_cycle(u64 period, u64 duty_cycle)
+{
+ if (!period)
+ return 0;
+
+ duty_cycle *= 256;
+ duty_cycle = DIV_ROUND_CLOSEST_ULL(duty_cycle, period);
+
+ /* Device is not able to generate 0% duty cycle */
+ if (!duty_cycle)
+ return -ERANGE;
+
+ return duty_cycle - 1;
+}
+
+static int mc33xs2410_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ const struct pwm_state *state)
+{
+ struct mc33xs2410_pwm *mc33xs2410 = to_pwm_mc33xs2410_chip(chip);
+ struct spi_device *spi = mc33xs2410->spi;
+ u8 reg[4] = {
+ MC33XS2410_PWM_FREQ(pwm->hwpwm + 1),
+ MC33XS2410_PWM_DC(pwm->hwpwm + 1),
+ MC33XS2410_PWM_CTRL1,
+ MC33XS2410_PWM_CTRL3
+ };
+ bool ctrl[2] = { true, true };
+ u64 period, duty_cycle;
+ u16 val[4];
+ u8 mask;
+ int ret;
+
+ period = min(state->period, MC33XS2410_MAX_PERIOD_STEP(0));
+ if (period < MC33XS2410_MIN_PERIOD_STEP(3) + 1)
+ return -EINVAL;
+
+ ret = mc33xs2410_read_regs(spi, ®[2], &ctrl[0], &val[2], 2);
+ if (ret < 0)
+ return ret;
+
+ /* frequency */
+ val[0] = mc33xs2410_pwm_get_freq(period);
+
+ /* duty cycle */
+ duty_cycle = min(period, state->duty_cycle);
+ ret = mc33xs2410_pwm_get_relative_duty_cycle(period, duty_cycle);
+ if (ret < 0)
+ return ret;
+
+ val[1] = ret;
+ /* polarity */
+ mask = MC33XS2410_PWM_CTRL1_POL_INV(pwm->hwpwm);
+ val[2] = (state->polarity == PWM_POLARITY_INVERSED) ?
+ (val[2] | mask) : (val[2] & ~mask);
+
+ /* enable output */
+ mask = MC33XS2410_PWM_CTRL3_EN(pwm->hwpwm);
+ val[3] = (state->enabled) ? (val[3] | mask) : (val[3] & ~mask);
+
+ return mc33xs2410_write_regs(spi, reg, val, 4);
+}
+
+static int mc33xs2410_pwm_get_state(struct pwm_chip *chip,
+ struct pwm_device *pwm,
+ struct pwm_state *state)
+{
+ struct mc33xs2410_pwm *mc33xs2410 = to_pwm_mc33xs2410_chip(chip);
+ struct spi_device *spi = mc33xs2410->spi;
+ u8 reg[4] = {
+ MC33XS2410_PWM_FREQ(pwm->hwpwm + 1),
+ MC33XS2410_PWM_DC(pwm->hwpwm + 1),
+ MC33XS2410_PWM_CTRL1,
+ MC33XS2410_PWM_CTRL3,
+ };
+ bool ctrl[4] = { true, true, true, true };
+ u16 val[4];
+ int ret;
+
+ ret = mc33xs2410_read_regs(spi, reg, ctrl, val, 4);
+ if (ret < 0)
+ return ret;
+
+ state->period = mc33xs2410_pwm_get_period(val[0]);
+ pwm_set_relative_duty_cycle(state, val[1] + 1, 256);
+ state->polarity = (val[2] & MC33XS2410_PWM_CTRL1_POL_INV(pwm->hwpwm)) ?
+ PWM_POLARITY_INVERSED : PWM_POLARITY_NORMAL;
+
+ state->enabled = !!(val[3] & MC33XS2410_PWM_CTRL3_EN(pwm->hwpwm));
+
+ return 0;
+}
+
+static const struct pwm_ops mc33xs2410_pwm_ops = {
+ .apply = mc33xs2410_pwm_apply,
+ .get_state = mc33xs2410_pwm_get_state,
+};
+
+static int mc33xs2410_reset(struct device *dev)
+{
+ struct gpio_desc *reset_gpio;
+
+ reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
+ if (IS_ERR_OR_NULL(reset_gpio))
+ return PTR_ERR_OR_ZERO(reset_gpio);
+
+ fsleep(1000);
+ gpiod_set_value_cansleep(reset_gpio, 0);
+ /* Wake-up time */
+ fsleep(10000);
+
+ return 0;
+}
+
+static int mc33xs2410_probe(struct spi_device *spi)
+{
+ struct mc33xs2410_pwm *mc33xs2410;
+ struct device *dev = &spi->dev;
+ struct pwm_chip *chip;
+ int ret;
+
+ chip = devm_pwmchip_alloc(dev, 4, sizeof(*mc33xs2410));
+ if (IS_ERR(chip))
+ return PTR_ERR(chip);
+
+ mc33xs2410 = to_pwm_mc33xs2410_chip(chip);
+ mc33xs2410->spi = spi;
+ chip->ops = &mc33xs2410_pwm_ops;
+
+ ret = mc33xs2410_reset(dev);
+ if (ret)
+ return ret;
+
+ /* Disable watchdog */
+ ret = mc33xs2410_write_reg(spi, MC33XS2410_WDT, 0x0);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Failed to disable watchdog\n");
+
+ /* Transition to normal mode */
+ ret = mc33xs2410_modify_reg(spi, MC33XS2410_GLB_CTRL,
+ MC33XS2410_GLB_CTRL_MODE_MASK,
+ MC33XS2410_GLB_CTRL_NORMAL_MODE);
+ if (ret < 0)
+ return dev_err_probe(dev, ret,
+ "Failed to transition to normal mode\n");
+
+ ret = devm_pwmchip_add(dev, chip);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Failed to add pwm chip\n");
+
+ return 0;
+}
+
+static const struct spi_device_id mc33xs2410_spi_id[] = {
+ { "mc33xs2410" },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, mc33xs2410_spi_id);
+
+static const struct of_device_id mc33xs2410_of_match[] = {
+ { .compatible = "nxp,mc33xs2410" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, mc33xs2410_of_match);
+
+static struct spi_driver mc33xs2410_driver = {
+ .driver = {
+ .name = "mc33xs2410-pwm",
+ .of_match_table = mc33xs2410_of_match,
+ },
+ .probe = mc33xs2410_probe,
+ .id_table = mc33xs2410_spi_id,
+};
+module_spi_driver(mc33xs2410_driver);
+
+MODULE_DESCRIPTION("NXP MC33XS2410 high-side switch driver");
+MODULE_AUTHOR("Dimitri Fedrau <dima.fedrau@gmail.com>");
+MODULE_LICENSE("GPL");
--
2.39.2
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