Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/pwm/pwm-imx1.c b/drivers/pwm/pwm-imx1.c
new file mode 100644
index 0000000..f8b2c2e
--- /dev/null
+++ b/drivers/pwm/pwm-imx1.c
@@ -0,0 +1,199 @@
+// 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/of_device.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, int duty_ns, int 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 = 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 const struct pwm_ops pwm_imx1_ops = {
+ .enable = pwm_imx1_enable,
+ .disable = pwm_imx1_disable,
+ .config = pwm_imx1_config,
+ .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;
+ struct resource *r;
+
+ imx = devm_kzalloc(&pdev->dev, sizeof(*imx), GFP_KERNEL);
+ if (!imx)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, imx);
+
+ imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
+ if (IS_ERR(imx->clk_ipg)) {
+ dev_err(&pdev->dev, "getting ipg clock failed with %ld\n",
+ PTR_ERR(imx->clk_ipg));
+ return PTR_ERR(imx->clk_ipg);
+ }
+
+ imx->clk_per = devm_clk_get(&pdev->dev, "per");
+ if (IS_ERR(imx->clk_per)) {
+ int ret = PTR_ERR(imx->clk_per);
+
+ if (ret != -EPROBE_DEFER)
+ dev_err(&pdev->dev,
+ "failed to get peripheral clock: %d\n",
+ ret);
+
+ return ret;
+ }
+
+ imx->chip.ops = &pwm_imx1_ops;
+ imx->chip.dev = &pdev->dev;
+ imx->chip.base = -1;
+ imx->chip.npwm = 1;
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ imx->mmio_base = devm_ioremap_resource(&pdev->dev, r);
+ if (IS_ERR(imx->mmio_base))
+ return PTR_ERR(imx->mmio_base);
+
+ return pwmchip_add(&imx->chip);
+}
+
+static int pwm_imx1_remove(struct platform_device *pdev)
+{
+ struct pwm_imx1_chip *imx = platform_get_drvdata(pdev);
+
+ pwm_imx1_clk_disable_unprepare(&imx->chip);
+
+ return pwmchip_remove(&imx->chip);
+}
+
+static struct platform_driver pwm_imx1_driver = {
+ .driver = {
+ .name = "pwm-imx1",
+ .of_match_table = pwm_imx1_dt_ids,
+ },
+ .probe = pwm_imx1_probe,
+ .remove = pwm_imx1_remove,
+};
+module_platform_driver(pwm_imx1_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");