Initial import

1 files changed, 181 insertions, 0 deletions

diff --git a/drivers/pwm/pwm-lpc32xx.c b/drivers/pwm/pwm-lpc32xx.c
new file mode 100644
index 000000000..9fde60ce8
--- /dev/null
+++ b/drivers/pwm/pwm-lpc32xx.c
@@ -0,0 +1,181 @@
+/*
+ * Copyright 2012 Alexandre Pereira da Silva <aletes.xgr@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2.
+ *
+ */
+
+#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/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/slab.h>
+
+struct lpc32xx_pwm_chip {
+	struct pwm_chip chip;
+	struct clk *clk;
+	void __iomem *base;
+};
+
+#define PWM_ENABLE	(1 << 31)
+#define PWM_RELOADV(x)	(((x) & 0xFF) << 8)
+#define PWM_DUTY(x)	((x) & 0xFF)
+
+#define to_lpc32xx_pwm_chip(_chip) \
+	container_of(_chip, struct lpc32xx_pwm_chip, chip)
+
+static int lpc32xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+			      int duty_ns, int period_ns)
+{
+	struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip);
+	unsigned long long c;
+	int period_cycles, duty_cycles;
+	u32 val;
+
+	c = clk_get_rate(lpc32xx->clk) / 256;
+	c = c * period_ns;
+	do_div(c, NSEC_PER_SEC);
+
+	/* Handle high and low extremes */
+	if (c == 0)
+		c = 1;
+	if (c > 255)
+		c = 0; /* 0 set division by 256 */
+	period_cycles = c;
+
+	/* The duty-cycle value is as follows:
+	 *
+	 *  DUTY-CYCLE     HIGH LEVEL
+	 *      1            99.9%
+	 *      25           90.0%
+	 *      128          50.0%
+	 *      220          10.0%
+	 *      255           0.1%
+	 *      0             0.0%
+	 *
+	 * In other words, the register value is duty-cycle % 256 with
+	 * duty-cycle in the range 1-256.
+	 */
+	c = 256 * duty_ns;
+	do_div(c, period_ns);
+	if (c > 255)
+		c = 255;
+	duty_cycles = 256 - c;
+
+	val = readl(lpc32xx->base + (pwm->hwpwm << 2));
+	val &= ~0xFFFF;
+	val |= PWM_RELOADV(period_cycles) | PWM_DUTY(duty_cycles);
+	writel(val, lpc32xx->base + (pwm->hwpwm << 2));
+
+	return 0;
+}
+
+static int lpc32xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip);
+	u32 val;
+	int ret;
+
+	ret = clk_enable(lpc32xx->clk);
+	if (ret)
+		return ret;
+
+	val = readl(lpc32xx->base + (pwm->hwpwm << 2));
+	val |= PWM_ENABLE;
+	writel(val, lpc32xx->base + (pwm->hwpwm << 2));
+
+	return 0;
+}
+
+static void lpc32xx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip);
+	u32 val;
+
+	val = readl(lpc32xx->base + (pwm->hwpwm << 2));
+	val &= ~PWM_ENABLE;
+	writel(val, lpc32xx->base + (pwm->hwpwm << 2));
+
+	clk_disable(lpc32xx->clk);
+}
+
+static const struct pwm_ops lpc32xx_pwm_ops = {
+	.config = lpc32xx_pwm_config,
+	.enable = lpc32xx_pwm_enable,
+	.disable = lpc32xx_pwm_disable,
+	.owner = THIS_MODULE,
+};
+
+static int lpc32xx_pwm_probe(struct platform_device *pdev)
+{
+	struct lpc32xx_pwm_chip *lpc32xx;
+	struct resource *res;
+	int ret;
+
+	lpc32xx = devm_kzalloc(&pdev->dev, sizeof(*lpc32xx), GFP_KERNEL);
+	if (!lpc32xx)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	lpc32xx->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(lpc32xx->base))
+		return PTR_ERR(lpc32xx->base);
+
+	lpc32xx->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(lpc32xx->clk))
+		return PTR_ERR(lpc32xx->clk);
+
+	lpc32xx->chip.dev = &pdev->dev;
+	lpc32xx->chip.ops = &lpc32xx_pwm_ops;
+	lpc32xx->chip.npwm = 2;
+	lpc32xx->chip.base = -1;
+
+	ret = pwmchip_add(&lpc32xx->chip);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to add PWM chip, error %d\n", ret);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, lpc32xx);
+
+	return 0;
+}
+
+static int lpc32xx_pwm_remove(struct platform_device *pdev)
+{
+	struct lpc32xx_pwm_chip *lpc32xx = platform_get_drvdata(pdev);
+	unsigned int i;
+
+	for (i = 0; i < lpc32xx->chip.npwm; i++)
+		pwm_disable(&lpc32xx->chip.pwms[i]);
+
+	return pwmchip_remove(&lpc32xx->chip);
+}
+
+static const struct of_device_id lpc32xx_pwm_dt_ids[] = {
+	{ .compatible = "nxp,lpc3220-pwm", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, lpc32xx_pwm_dt_ids);
+
+static struct platform_driver lpc32xx_pwm_driver = {
+	.driver = {
+		.name = "lpc32xx-pwm",
+		.of_match_table = lpc32xx_pwm_dt_ids,
+	},
+	.probe = lpc32xx_pwm_probe,
+	.remove = lpc32xx_pwm_remove,
+};
+module_platform_driver(lpc32xx_pwm_driver);
+
+MODULE_ALIAS("platform:lpc32xx-pwm");
+MODULE_AUTHOR("Alexandre Pereira da Silva <aletes.xgr@gmail.com>");
+MODULE_DESCRIPTION("LPC32XX PWM Driver");
+MODULE_LICENSE("GPL v2");