Adding upstream version 6.6.15.upstream/6.6.15

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

1 files changed, 180 insertions, 0 deletions

diff --git a/drivers/pwm/pwm-mxs.c b/drivers/pwm/pwm-mxs.c
new file mode 100644
index 0000000000..766dbc58da
--- /dev/null
+++ b/drivers/pwm/pwm-mxs.c
@@ -0,0 +1,180 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2012 Freescale Semiconductor, Inc.
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/slab.h>
+#include <linux/stmp_device.h>
+
+#define SET	0x4
+#define CLR	0x8
+#define TOG	0xc
+
+#define PWM_CTRL		0x0
+#define PWM_ACTIVE0		0x10
+#define PWM_PERIOD0		0x20
+#define  PERIOD_PERIOD(p)	((p) & 0xffff)
+#define  PERIOD_PERIOD_MAX	0x10000
+#define  PERIOD_ACTIVE_HIGH	(3 << 16)
+#define  PERIOD_ACTIVE_LOW	(2 << 16)
+#define  PERIOD_INACTIVE_HIGH	(3 << 18)
+#define  PERIOD_INACTIVE_LOW	(2 << 18)
+#define  PERIOD_POLARITY_NORMAL	(PERIOD_ACTIVE_HIGH | PERIOD_INACTIVE_LOW)
+#define  PERIOD_POLARITY_INVERSE	(PERIOD_ACTIVE_LOW | PERIOD_INACTIVE_HIGH)
+#define  PERIOD_CDIV(div)	(((div) & 0x7) << 20)
+#define  PERIOD_CDIV_MAX	8
+
+static const u8 cdiv_shift[PERIOD_CDIV_MAX] = {
+	0, 1, 2, 3, 4, 6, 8, 10
+};
+
+struct mxs_pwm_chip {
+	struct pwm_chip chip;
+	struct clk *clk;
+	void __iomem *base;
+};
+
+#define to_mxs_pwm_chip(_chip) container_of(_chip, struct mxs_pwm_chip, chip)
+
+static int mxs_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			 const struct pwm_state *state)
+{
+	struct mxs_pwm_chip *mxs = to_mxs_pwm_chip(chip);
+	int ret, div = 0;
+	unsigned int period_cycles, duty_cycles;
+	unsigned long rate;
+	unsigned long long c;
+	unsigned int pol_bits;
+
+	/*
+	 * If the PWM channel is disabled, make sure to turn on the
+	 * clock before calling clk_get_rate() and writing to the
+	 * registers. Otherwise, just keep it enabled.
+	 */
+	if (!pwm_is_enabled(pwm)) {
+		ret = clk_prepare_enable(mxs->clk);
+		if (ret)
+			return ret;
+	}
+
+	if (!state->enabled && pwm_is_enabled(pwm))
+		writel(1 << pwm->hwpwm, mxs->base + PWM_CTRL + CLR);
+
+	rate = clk_get_rate(mxs->clk);
+	while (1) {
+		c = rate >> cdiv_shift[div];
+		c = c * state->period;
+		do_div(c, 1000000000);
+		if (c < PERIOD_PERIOD_MAX)
+			break;
+		div++;
+		if (div >= PERIOD_CDIV_MAX)
+			return -EINVAL;
+	}
+
+	period_cycles = c;
+	c *= state->duty_cycle;
+	do_div(c, state->period);
+	duty_cycles = c;
+
+	/*
+	 * The data sheet the says registers must be written to in
+	 * this order (ACTIVEn, then PERIODn). Also, the new settings
+	 * only take effect at the beginning of a new period, avoiding
+	 * glitches.
+	 */
+
+	pol_bits = state->polarity == PWM_POLARITY_NORMAL ?
+		PERIOD_POLARITY_NORMAL : PERIOD_POLARITY_INVERSE;
+	writel(duty_cycles << 16,
+	       mxs->base + PWM_ACTIVE0 + pwm->hwpwm * 0x20);
+	writel(PERIOD_PERIOD(period_cycles) | pol_bits | PERIOD_CDIV(div),
+	       mxs->base + PWM_PERIOD0 + pwm->hwpwm * 0x20);
+
+	if (state->enabled) {
+		if (!pwm_is_enabled(pwm)) {
+			/*
+			 * The clock was enabled above. Just enable
+			 * the channel in the control register.
+			 */
+			writel(1 << pwm->hwpwm, mxs->base + PWM_CTRL + SET);
+		}
+	} else {
+		clk_disable_unprepare(mxs->clk);
+	}
+	return 0;
+}
+
+static const struct pwm_ops mxs_pwm_ops = {
+	.apply = mxs_pwm_apply,
+	.owner = THIS_MODULE,
+};
+
+static int mxs_pwm_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct mxs_pwm_chip *mxs;
+	int ret;
+
+	mxs = devm_kzalloc(&pdev->dev, sizeof(*mxs), GFP_KERNEL);
+	if (!mxs)
+		return -ENOMEM;
+
+	mxs->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(mxs->base))
+		return PTR_ERR(mxs->base);
+
+	mxs->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(mxs->clk))
+		return PTR_ERR(mxs->clk);
+
+	mxs->chip.dev = &pdev->dev;
+	mxs->chip.ops = &mxs_pwm_ops;
+
+	ret = of_property_read_u32(np, "fsl,pwm-number", &mxs->chip.npwm);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to get pwm number: %d\n", ret);
+		return ret;
+	}
+
+	/* FIXME: Only do this if the PWM isn't already running */
+	ret = stmp_reset_block(mxs->base);
+	if (ret)
+		return dev_err_probe(&pdev->dev, ret, "failed to reset PWM\n");
+
+	ret = devm_pwmchip_add(&pdev->dev, &mxs->chip);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to add pwm chip %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id mxs_pwm_dt_ids[] = {
+	{ .compatible = "fsl,imx23-pwm", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mxs_pwm_dt_ids);
+
+static struct platform_driver mxs_pwm_driver = {
+	.driver = {
+		.name = "mxs-pwm",
+		.of_match_table = mxs_pwm_dt_ids,
+	},
+	.probe = mxs_pwm_probe,
+};
+module_platform_driver(mxs_pwm_driver);
+
+MODULE_ALIAS("platform:mxs-pwm");
+MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>");
+MODULE_DESCRIPTION("Freescale MXS PWM Driver");
+MODULE_LICENSE("GPL v2");