pwm: Move PXA PWM driver to PWM framework

This commit moves the PXA PWM driver to the drivers/pwm subdirectory and
converts it to use the new PWM framework.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>

1 files changed, 248 insertions, 0 deletions

diff --git a/drivers/pwm/pwm-pxa.c b/drivers/pwm/pwm-pxa.c
new file mode 100644
index 000000000000..d5c6ce513e29
--- /dev/null
+++ b/drivers/pwm/pwm-pxa.c
@@ -0,0 +1,248 @@
+/*
+ * linux/arch/arm/mach-pxa/pwm.c
+ *
+ * simple driver for PWM (Pulse Width Modulator) controller
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 2008-02-13   initial version
+ *              eric miao <eric.miao@marvell.com>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/pwm.h>
+
+#include <asm/div64.h>
+
+#define HAS_SECONDARY_PWM       0x10
+#define PWM_ID_BASE(d)          ((d) & 0xf)
+
+static const struct platform_device_id pwm_id_table[] = {
+        /*   PWM    has_secondary_pwm? */
+        { "pxa25x-pwm", 0 },
+        { "pxa27x-pwm", 0 | HAS_SECONDARY_PWM },
+        { "pxa168-pwm", 1 },
+        { "pxa910-pwm", 1 },
+        { },
+};
+MODULE_DEVICE_TABLE(platform, pwm_id_table);
+
+/* PWM registers and bits definitions */
+#define PWMCR           (0x00)
+#define PWMDCR          (0x04)
+#define PWMPCR          (0x08)
+
+#define PWMCR_SD        (1 << 6)
+#define PWMDCR_FD       (1 << 10)
+
+struct pxa_pwm_chip {
+        struct pwm_chip chip;
+        struct device   *dev;
+
+        struct clk      *clk;
+        int             clk_enabled;
+        void __iomem    *mmio_base;
+};
+
+static inline struct pxa_pwm_chip *to_pxa_pwm_chip(struct pwm_chip *chip)
+{
+        return container_of(chip, struct pxa_pwm_chip, chip);
+}
+
+/*
+ * period_ns = 10^9 * (PRESCALE + 1) * (PV + 1) / PWM_CLK_RATE
+ * duty_ns   = 10^9 * (PRESCALE + 1) * DC / PWM_CLK_RATE
+ */
+static int pxa_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+                          int duty_ns, int period_ns)
+{
+        struct pxa_pwm_chip *pc = to_pxa_pwm_chip(chip);
+        unsigned long long c;
+        unsigned long period_cycles, prescale, pv, dc;
+        unsigned long offset;
+        int rc;
+
+        if (period_ns == 0 || duty_ns > period_ns)
+                return -EINVAL;
+
+        offset = pwm->hwpwm ? 0x10 : 0;
+
+        c = clk_get_rate(pc->clk);
+        c = c * period_ns;
+        do_div(c, 1000000000);
+        period_cycles = c;
+
+        if (period_cycles < 1)
+                period_cycles = 1;
+        prescale = (period_cycles - 1) / 1024;
+        pv = period_cycles / (prescale + 1) - 1;
+
+        if (prescale > 63)
+                return -EINVAL;
+
+        if (duty_ns == period_ns)
+                dc = PWMDCR_FD;
+        else
+                dc = (pv + 1) * duty_ns / period_ns;
+
+        /* NOTE: the clock to PWM has to be enabled first
+         * before writing to the registers
+         */
+        rc = clk_prepare_enable(pc->clk);
+        if (rc < 0)
+                return rc;
+
+        writel(prescale, pc->mmio_base + offset + PWMCR);
+        writel(dc, pc->mmio_base + offset + PWMDCR);
+        writel(pv, pc->mmio_base + offset + PWMPCR);
+
+        clk_disable_unprepare(pc->clk);
+        return 0;
+}
+
+static int pxa_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+        struct pxa_pwm_chip *pc = to_pxa_pwm_chip(chip);
+        int rc = 0;
+
+        if (!pc->clk_enabled) {
+                rc = clk_prepare_enable(pc->clk);
+                if (!rc)
+                        pc->clk_enabled++;
+        }
+        return rc;
+}
+
+static void pxa_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+        struct pxa_pwm_chip *pc = to_pxa_pwm_chip(chip);
+
+        if (pc->clk_enabled) {
+                clk_disable_unprepare(pc->clk);
+                pc->clk_enabled--;
+        }
+}
+
+static struct pwm_ops pxa_pwm_ops = {
+        .config = pxa_pwm_config,
+        .enable = pxa_pwm_enable,
+        .disable = pxa_pwm_disable,
+        .owner = THIS_MODULE,
+};
+
+static int __devinit pwm_probe(struct platform_device *pdev)
+{
+        const struct platform_device_id *id = platform_get_device_id(pdev);
+        struct pxa_pwm_chip *pwm;
+        struct resource *r;
+        int ret = 0;
+
+        pwm = kzalloc(sizeof(*pwm), GFP_KERNEL);
+        if (pwm == NULL) {
+                dev_err(&pdev->dev, "failed to allocate memory\n");
+                return -ENOMEM;
+        }
+
+        pwm->clk = clk_get(&pdev->dev, NULL);
+        if (IS_ERR(pwm->clk)) {
+                ret = PTR_ERR(pwm->clk);
+                goto err_free;
+        }
+        pwm->clk_enabled = 0;
+
+        pwm->chip.dev = &pdev->dev;
+        pwm->chip.ops = &pxa_pwm_ops;
+        pwm->chip.base = -1;
+        pwm->chip.npwm = (id->driver_data & HAS_SECONDARY_PWM) ? 2 : 1;
+
+        r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (r == NULL) {
+                dev_err(&pdev->dev, "no memory resource defined\n");
+                ret = -ENODEV;
+                goto err_free_clk;
+        }
+
+        r = request_mem_region(r->start, resource_size(r), pdev->name);
+        if (r == NULL) {
+                dev_err(&pdev->dev, "failed to request memory resource\n");
+                ret = -EBUSY;
+                goto err_free_clk;
+        }
+
+        pwm->mmio_base = ioremap(r->start, resource_size(r));
+        if (pwm->mmio_base == NULL) {
+                dev_err(&pdev->dev, "failed to ioremap() registers\n");
+                ret = -ENODEV;
+                goto err_free_mem;
+        }
+
+        ret = pwmchip_add(&pwm->chip);
+        if (ret < 0) {
+                dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
+                return ret;
+        }
+
+        platform_set_drvdata(pdev, pwm);
+        return 0;
+
+err_free_mem:
+        release_mem_region(r->start, resource_size(r));
+err_free_clk:
+        clk_put(pwm->clk);
+err_free:
+        kfree(pwm);
+        return ret;
+}
+
+static int __devexit pwm_remove(struct platform_device *pdev)
+{
+        struct pxa_pwm_chip *chip;
+        struct resource *r;
+
+        chip = platform_get_drvdata(pdev);
+        if (chip == NULL)
+                return -ENODEV;
+
+        pwmchip_remove(&chip->chip);
+
+        iounmap(chip->mmio_base);
+
+        r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        release_mem_region(r->start, resource_size(r));
+
+        clk_put(chip->clk);
+        kfree(chip);
+        return 0;
+}
+
+static struct platform_driver pwm_driver = {
+        .driver         = {
+                .name   = "pxa25x-pwm",
+                .owner  = THIS_MODULE,
+        },
+        .probe          = pwm_probe,
+        .remove         = __devexit_p(pwm_remove),
+        .id_table       = pwm_id_table,
+};
+
+static int __init pwm_init(void)
+{
+        return platform_driver_register(&pwm_driver);
+}
+arch_initcall(pwm_init);
+
+static void __exit pwm_exit(void)
+{
+        platform_driver_unregister(&pwm_driver);
+}
+module_exit(pwm_exit);
+
+MODULE_LICENSE("GPL v2");