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>

3 files changed, 159 insertions, 0 deletions

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 0b2800fc1ca7..94e176e26f4c 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -28,6 +28,16 @@ config PWM_IMX
           To compile this driver as a module, choose M here: the module
           will be called pwm-imx.
 
+config PWM_LPC32XX
+        tristate "LPC32XX PWM support"
+        depends on ARCH_LPC32XX
+        help
+          Generic PWM framework driver for LPC32XX. The LPC32XX SOC has two
+          PWM controllers.
+
+          To compile this driver as a module, choose M here: the module
+          will be called pwm-lpc32xx.
+
 config PWM_MXS
         tristate "Freescale MXS PWM support"
         depends on ARCH_MXS && OF
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index cec250091cff..54597020350f 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -1,6 +1,7 @@
 obj-$(CONFIG_PWM)               += core.o
 obj-$(CONFIG_PWM_BFIN)          += pwm-bfin.o
 obj-$(CONFIG_PWM_IMX)           += pwm-imx.o
+obj-$(CONFIG_PWM_LPC32XX)       += pwm-lpc32xx.o
 obj-$(CONFIG_PWM_MXS)           += pwm-mxs.o
 obj-$(CONFIG_PWM_PXA)           += pwm-pxa.o
 obj-$(CONFIG_PWM_SAMSUNG)       += pwm-samsung.o
diff --git a/drivers/pwm/pwm-lpc32xx.c b/drivers/pwm/pwm-lpc32xx.c
new file mode 100644
index 000000000000..adb87f0c1633
--- /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");