pwm: add lpc32xx PWM support
Add lpc32xx SOC PWM driver.
Signed-off-by: Alexandre Pereira da Silva <aletes.xgr@gmail.com>
Acked-by: Roland Stigge <stigge@antcom.de>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
diff --git a/drivers/pwm/pwm-lpc32xx.c b/drivers/pwm/pwm-lpc32xx.c
new file mode 100644
index 0000000..adb87f0
--- /dev/null
+++ b/drivers/pwm/pwm-lpc32xx.c
@@ -0,0 +1,148 @@
+/*
+ * 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;
+
+ 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;
+
+ c = 256 * duty_ns;
+ do_div(c, period_ns);
+ duty_cycles = c;
+
+ writel(PWM_ENABLE | PWM_RELOADV(period_cycles) | PWM_DUTY(duty_cycles),
+ 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);
+
+ return clk_enable(lpc32xx->clk);
+}
+
+static void lpc32xx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip);
+
+ writel(0, 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);
+ if (!res)
+ return -EINVAL;
+
+ lpc32xx->base = devm_request_and_ioremap(&pdev->dev, res);
+ if (!lpc32xx->base)
+ return -EADDRNOTAVAIL;
+
+ 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;
+
+ 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 __devexit lpc32xx_pwm_remove(struct platform_device *pdev)
+{
+ struct lpc32xx_pwm_chip *lpc32xx = platform_get_drvdata(pdev);
+
+ clk_disable(lpc32xx->clk);
+ return pwmchip_remove(&lpc32xx->chip);
+}
+
+static 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 = of_match_ptr(lpc32xx_pwm_dt_ids),
+ },
+ .probe = lpc32xx_pwm_probe,
+ .remove = __devexit_p(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");