Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 203 insertions, 0 deletions

diff --git a/drivers/pwm/pwm-bcm2835.c b/drivers/pwm/pwm-bcm2835.c
new file mode 100644
index 0000000000..bdfc2a5ec0
--- /dev/null
+++ b/drivers/pwm/pwm-bcm2835.c
@@ -0,0 +1,203 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2014 Bart Tanghe <bart.tanghe@thomasmore.be>
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+
+#define PWM_CONTROL		0x000
+#define PWM_CONTROL_SHIFT(x)	((x) * 8)
+#define PWM_CONTROL_MASK	0xff
+#define PWM_MODE		0x80		/* set timer in PWM mode */
+#define PWM_ENABLE		(1 << 0)
+#define PWM_POLARITY		(1 << 4)
+
+#define PERIOD(x)		(((x) * 0x10) + 0x10)
+#define DUTY(x)			(((x) * 0x10) + 0x14)
+
+#define PERIOD_MIN		0x2
+
+struct bcm2835_pwm {
+	struct pwm_chip chip;
+	struct device *dev;
+	void __iomem *base;
+	struct clk *clk;
+};
+
+static inline struct bcm2835_pwm *to_bcm2835_pwm(struct pwm_chip *chip)
+{
+	return container_of(chip, struct bcm2835_pwm, chip);
+}
+
+static int bcm2835_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct bcm2835_pwm *pc = to_bcm2835_pwm(chip);
+	u32 value;
+
+	value = readl(pc->base + PWM_CONTROL);
+	value &= ~(PWM_CONTROL_MASK << PWM_CONTROL_SHIFT(pwm->hwpwm));
+	value |= (PWM_MODE << PWM_CONTROL_SHIFT(pwm->hwpwm));
+	writel(value, pc->base + PWM_CONTROL);
+
+	return 0;
+}
+
+static void bcm2835_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct bcm2835_pwm *pc = to_bcm2835_pwm(chip);
+	u32 value;
+
+	value = readl(pc->base + PWM_CONTROL);
+	value &= ~(PWM_CONTROL_MASK << PWM_CONTROL_SHIFT(pwm->hwpwm));
+	writel(value, pc->base + PWM_CONTROL);
+}
+
+static int bcm2835_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			     const struct pwm_state *state)
+{
+
+	struct bcm2835_pwm *pc = to_bcm2835_pwm(chip);
+	unsigned long rate = clk_get_rate(pc->clk);
+	unsigned long long period_cycles;
+	u64 max_period;
+
+	u32 val;
+
+	if (!rate) {
+		dev_err(pc->dev, "failed to get clock rate\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * period_cycles must be a 32 bit value, so period * rate / NSEC_PER_SEC
+	 * must be <= U32_MAX. As U32_MAX * NSEC_PER_SEC < U64_MAX the
+	 * multiplication period * rate doesn't overflow.
+	 * To calculate the maximal possible period that guarantees the
+	 * above inequality:
+	 *
+	 *     round(period * rate / NSEC_PER_SEC) <= U32_MAX
+	 * <=> period * rate / NSEC_PER_SEC < U32_MAX + 0.5
+	 * <=> period * rate < (U32_MAX + 0.5) * NSEC_PER_SEC
+	 * <=> period < ((U32_MAX + 0.5) * NSEC_PER_SEC) / rate
+	 * <=> period < ((U32_MAX * NSEC_PER_SEC + NSEC_PER_SEC/2) / rate
+	 * <=> period <= ceil((U32_MAX * NSEC_PER_SEC + NSEC_PER_SEC/2) / rate) - 1
+	 */
+	max_period = DIV_ROUND_UP_ULL((u64)U32_MAX * NSEC_PER_SEC + NSEC_PER_SEC / 2, rate) - 1;
+
+	if (state->period > max_period)
+		return -EINVAL;
+
+	/* set period */
+	period_cycles = DIV_ROUND_CLOSEST_ULL(state->period * rate, NSEC_PER_SEC);
+
+	/* don't accept a period that is too small */
+	if (period_cycles < PERIOD_MIN)
+		return -EINVAL;
+
+	writel(period_cycles, pc->base + PERIOD(pwm->hwpwm));
+
+	/* set duty cycle */
+	val = DIV_ROUND_CLOSEST_ULL(state->duty_cycle * rate, NSEC_PER_SEC);
+	writel(val, pc->base + DUTY(pwm->hwpwm));
+
+	/* set polarity */
+	val = readl(pc->base + PWM_CONTROL);
+
+	if (state->polarity == PWM_POLARITY_NORMAL)
+		val &= ~(PWM_POLARITY << PWM_CONTROL_SHIFT(pwm->hwpwm));
+	else
+		val |= PWM_POLARITY << PWM_CONTROL_SHIFT(pwm->hwpwm);
+
+	/* enable/disable */
+	if (state->enabled)
+		val |= PWM_ENABLE << PWM_CONTROL_SHIFT(pwm->hwpwm);
+	else
+		val &= ~(PWM_ENABLE << PWM_CONTROL_SHIFT(pwm->hwpwm));
+
+	writel(val, pc->base + PWM_CONTROL);
+
+	return 0;
+}
+
+static const struct pwm_ops bcm2835_pwm_ops = {
+	.request = bcm2835_pwm_request,
+	.free = bcm2835_pwm_free,
+	.apply = bcm2835_pwm_apply,
+	.owner = THIS_MODULE,
+};
+
+static int bcm2835_pwm_probe(struct platform_device *pdev)
+{
+	struct bcm2835_pwm *pc;
+	int ret;
+
+	pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
+	if (!pc)
+		return -ENOMEM;
+
+	pc->dev = &pdev->dev;
+
+	pc->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(pc->base))
+		return PTR_ERR(pc->base);
+
+	pc->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(pc->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk),
+				     "clock not found\n");
+
+	ret = clk_prepare_enable(pc->clk);
+	if (ret)
+		return ret;
+
+	pc->chip.dev = &pdev->dev;
+	pc->chip.ops = &bcm2835_pwm_ops;
+	pc->chip.npwm = 2;
+
+	platform_set_drvdata(pdev, pc);
+
+	ret = pwmchip_add(&pc->chip);
+	if (ret < 0)
+		goto add_fail;
+
+	return 0;
+
+add_fail:
+	clk_disable_unprepare(pc->clk);
+	return ret;
+}
+
+static void bcm2835_pwm_remove(struct platform_device *pdev)
+{
+	struct bcm2835_pwm *pc = platform_get_drvdata(pdev);
+
+	pwmchip_remove(&pc->chip);
+
+	clk_disable_unprepare(pc->clk);
+}
+
+static const struct of_device_id bcm2835_pwm_of_match[] = {
+	{ .compatible = "brcm,bcm2835-pwm", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, bcm2835_pwm_of_match);
+
+static struct platform_driver bcm2835_pwm_driver = {
+	.driver = {
+		.name = "bcm2835-pwm",
+		.of_match_table = bcm2835_pwm_of_match,
+	},
+	.probe = bcm2835_pwm_probe,
+	.remove_new = bcm2835_pwm_remove,
+};
+module_platform_driver(bcm2835_pwm_driver);
+
+MODULE_AUTHOR("Bart Tanghe <bart.tanghe@thomasmore.be>");
+MODULE_DESCRIPTION("Broadcom BCM2835 PWM driver");
+MODULE_LICENSE("GPL v2");