Adding upstream version 6.6.15.upstream/6.6.15

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

1 files changed, 197 insertions, 0 deletions

diff --git a/drivers/pwm/pwm-imx1.c b/drivers/pwm/pwm-imx1.c
new file mode 100644
index 0000000000..0651983bed
--- /dev/null
+++ b/drivers/pwm/pwm-imx1.c
@@ -0,0 +1,197 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * simple driver for PWM (Pulse Width Modulator) controller
+ *
+ * Derived from pxa PWM driver by eric miao <eric.miao@marvell.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/delay.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>
+
+#define MX1_PWMC			0x00   /* PWM Control Register */
+#define MX1_PWMS			0x04   /* PWM Sample Register */
+#define MX1_PWMP			0x08   /* PWM Period Register */
+
+#define MX1_PWMC_EN			BIT(4)
+
+struct pwm_imx1_chip {
+	struct clk *clk_ipg;
+	struct clk *clk_per;
+	void __iomem *mmio_base;
+	struct pwm_chip chip;
+};
+
+#define to_pwm_imx1_chip(chip)	container_of(chip, struct pwm_imx1_chip, chip)
+
+static int pwm_imx1_clk_prepare_enable(struct pwm_chip *chip)
+{
+	struct pwm_imx1_chip *imx = to_pwm_imx1_chip(chip);
+	int ret;
+
+	ret = clk_prepare_enable(imx->clk_ipg);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(imx->clk_per);
+	if (ret) {
+		clk_disable_unprepare(imx->clk_ipg);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void pwm_imx1_clk_disable_unprepare(struct pwm_chip *chip)
+{
+	struct pwm_imx1_chip *imx = to_pwm_imx1_chip(chip);
+
+	clk_disable_unprepare(imx->clk_per);
+	clk_disable_unprepare(imx->clk_ipg);
+}
+
+static int pwm_imx1_config(struct pwm_chip *chip,
+			   struct pwm_device *pwm, u64 duty_ns, u64 period_ns)
+{
+	struct pwm_imx1_chip *imx = to_pwm_imx1_chip(chip);
+	u32 max, p;
+
+	/*
+	 * The PWM subsystem allows for exact frequencies. However,
+	 * I cannot connect a scope on my device to the PWM line and
+	 * thus cannot provide the program the PWM controller
+	 * exactly. Instead, I'm relying on the fact that the
+	 * Bootloader (u-boot or WinCE+haret) has programmed the PWM
+	 * function group already. So I'll just modify the PWM sample
+	 * register to follow the ratio of duty_ns vs. period_ns
+	 * accordingly.
+	 *
+	 * This is good enough for programming the brightness of
+	 * the LCD backlight.
+	 *
+	 * The real implementation would divide PERCLK[0] first by
+	 * both the prescaler (/1 .. /128) and then by CLKSEL
+	 * (/2 .. /16).
+	 */
+	max = readl(imx->mmio_base + MX1_PWMP);
+	p = mul_u64_u64_div_u64(max, duty_ns, period_ns);
+
+	writel(max - p, imx->mmio_base + MX1_PWMS);
+
+	return 0;
+}
+
+static int pwm_imx1_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct pwm_imx1_chip *imx = to_pwm_imx1_chip(chip);
+	u32 value;
+	int ret;
+
+	ret = pwm_imx1_clk_prepare_enable(chip);
+	if (ret < 0)
+		return ret;
+
+	value = readl(imx->mmio_base + MX1_PWMC);
+	value |= MX1_PWMC_EN;
+	writel(value, imx->mmio_base + MX1_PWMC);
+
+	return 0;
+}
+
+static void pwm_imx1_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct pwm_imx1_chip *imx = to_pwm_imx1_chip(chip);
+	u32 value;
+
+	value = readl(imx->mmio_base + MX1_PWMC);
+	value &= ~MX1_PWMC_EN;
+	writel(value, imx->mmio_base + MX1_PWMC);
+
+	pwm_imx1_clk_disable_unprepare(chip);
+}
+
+static int pwm_imx1_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			  const struct pwm_state *state)
+{
+	int err;
+
+	if (state->polarity != PWM_POLARITY_NORMAL)
+		return -EINVAL;
+
+	if (!state->enabled) {
+		if (pwm->state.enabled)
+			pwm_imx1_disable(chip, pwm);
+
+		return 0;
+	}
+
+	err = pwm_imx1_config(chip, pwm, state->duty_cycle, state->period);
+	if (err)
+		return err;
+
+	if (!pwm->state.enabled)
+		return pwm_imx1_enable(chip, pwm);
+
+	return 0;
+}
+
+static const struct pwm_ops pwm_imx1_ops = {
+	.apply = pwm_imx1_apply,
+	.owner = THIS_MODULE,
+};
+
+static const struct of_device_id pwm_imx1_dt_ids[] = {
+	{ .compatible = "fsl,imx1-pwm", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, pwm_imx1_dt_ids);
+
+static int pwm_imx1_probe(struct platform_device *pdev)
+{
+	struct pwm_imx1_chip *imx;
+
+	imx = devm_kzalloc(&pdev->dev, sizeof(*imx), GFP_KERNEL);
+	if (!imx)
+		return -ENOMEM;
+
+	imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
+	if (IS_ERR(imx->clk_ipg))
+		return dev_err_probe(&pdev->dev, PTR_ERR(imx->clk_ipg),
+				     "getting ipg clock failed\n");
+
+	imx->clk_per = devm_clk_get(&pdev->dev, "per");
+	if (IS_ERR(imx->clk_per))
+		return dev_err_probe(&pdev->dev, PTR_ERR(imx->clk_per),
+				     "failed to get peripheral clock\n");
+
+	imx->chip.ops = &pwm_imx1_ops;
+	imx->chip.dev = &pdev->dev;
+	imx->chip.npwm = 1;
+
+	imx->mmio_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(imx->mmio_base))
+		return PTR_ERR(imx->mmio_base);
+
+	return devm_pwmchip_add(&pdev->dev, &imx->chip);
+}
+
+static struct platform_driver pwm_imx1_driver = {
+	.driver = {
+		.name = "pwm-imx1",
+		.of_match_table = pwm_imx1_dt_ids,
+	},
+	.probe = pwm_imx1_probe,
+};
+module_platform_driver(pwm_imx1_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");