--- /dev/null
+/*
+ * 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.
+ *
+ * Derived from pxa PWM driver by eric miao <eric.miao@marvell.com>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/pwm.h>
+
+#if defined CONFIG_ARCH_MX1 || defined CONFIG_ARCH_MX21
+#define PWM_VER_1
+
+#define PWMCR 0x00 /* PWM Control Register */
+#define PWMSR 0x04 /* PWM Sample Register */
+#define PWMPR 0x08 /* PWM Period Register */
+#define PWMCNR 0x0C /* PWM Counter Register */
+
+#define PWMCR_HCTR (1 << 18) /* Halfword FIFO Data Swapping */
+#define PWMCR_BCTR (1 << 17) /* Byte FIFO Data Swapping */
+#define PWMCR_SWR (1 << 16) /* Software Reset */
+#define PWMCR_CLKSRC_PERCLK (0 << 15) /* PERCLK Clock Source */
+#define PWMCR_CLKSRC_CLK32 (1 << 15) /* 32KHz Clock Source */
+#define PWMCR_PRESCALER(x) (((x - 1) & 0x7F) << 8) /* PRESCALER */
+#define PWMCR_IRQ (1 << 7) /* Interrupt Request */
+#define PWMCR_IRQEN (1 << 6) /* Interrupt Request Enable */
+#define PWMCR_FIFOAV (1 << 5) /* FIFO Available */
+#define PWMCR_EN (1 << 4) /* Enables/Disables the PWM */
+#define PWMCR_REPEAT(x) (((x) & 0x03) << 2) /* Sample Repeats */
+#define PWMCR_DIV(x) (((x) & 0x03) << 0) /* Clock divider 2/4/8/16 */
+
+#define MAX_DIV (128 * 16)
+#endif
+
+#if defined CONFIG_MACH_MX27 || defined CONFIG_ARCH_MX31
+#define PWM_VER_2
+
+#define PWMCR 0x00 /* PWM Control Register */
+#define PWMSR 0x04 /* PWM Status Register */
+#define PWMIR 0x08 /* PWM Interrupt Register */
+#define PWMSAR 0x0C /* PWM Sample Register */
+#define PWMPR 0x10 /* PWM Period Register */
+#define PWMCNR 0x14 /* PWM Counter Register */
+
+#define PWMCR_EN (1 << 0) /* Enables/Disables the PWM */
+#define PWMCR_REPEAT(x) (((x) & 0x03) << 1) /* Sample Repeats */
+#define PWMCR_SWR (1 << 3) /* Software Reset */
+#define PWMCR_PRESCALER(x) (((x - 1) & 0xFFF) << 4)/* PRESCALER */
+#define PWMCR_CLKSRC(x) (((x) & 0x3) << 16)
+#define PWMCR_CLKSRC_OFF (0 << 16)
+#define PWMCR_CLKSRC_IPG (1 << 16)
+#define PWMCR_CLKSRC_IPG_HIGH (2 << 16)
+#define PWMCR_CLKSRC_CLK32 (3 << 16)
+#define PWMCR_POUTC
+#define PWMCR_HCTR (1 << 20) /* Halfword FIFO Data Swapping */
+#define PWMCR_BCTR (1 << 21) /* Byte FIFO Data Swapping */
+#define PWMCR_DBGEN (1 << 22) /* Debug Mode */
+#define PWMCR_WAITEN (1 << 23) /* Wait Mode */
+#define PWMCR_DOZEN (1 << 24) /* Doze Mode */
+#define PWMCR_STOPEN (1 << 25) /* Stop Mode */
+#define PWMCR_FWM(x) (((x) & 0x3) << 26) /* FIFO Water Mark */
+
+#define MAX_DIV 4096
+#endif
+
+#define PWMS_SAMPLE(x) ((x) & 0xFFFF) /* Contains a two-sample word */
+#define PWMP_PERIOD(x) ((x) & 0xFFFF) /* Represents the PWM's period */
+#define PWMC_COUNTER(x) ((x) & 0xFFFF) /* Represents the current count value */
+
+struct pwm_device {
+ struct list_head node;
+ struct platform_device *pdev;
+
+ const char *label;
+ struct clk *clk;
+
+ int clk_enabled;
+ void __iomem *mmio_base;
+
+ unsigned int use_count;
+ unsigned int pwm_id;
+};
+
+int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
+{
+ unsigned long long c;
+ unsigned long period_cycles, duty_cycles, prescale;
+
+ if (pwm == NULL || period_ns == 0 || duty_ns > period_ns)
+ return -EINVAL;
+
+ c = clk_get_rate(pwm->clk);
+ c = c * period_ns;
+ do_div(c, 1000000000);
+ period_cycles = c;
+
+ prescale = period_cycles / 0x10000 + 1;
+
+ period_cycles /= prescale;
+ c = (unsigned long long)period_cycles * duty_ns;
+ do_div(c, period_ns);
+ duty_cycles = c;
+
+#ifdef PWM_VER_2
+ writel(duty_cycles, pwm->mmio_base + PWMSAR);
+ writel(period_cycles, pwm->mmio_base + PWMPR);
+ writel(PWMCR_PRESCALER(prescale - 1) | PWMCR_CLKSRC_IPG_HIGH | PWMCR_EN,
+ pwm->mmio_base + PWMCR);
+#elif defined PWM_VER_1
+#error PWM not yet working on MX1 / MX21
+#endif
+
+ return 0;
+}
+EXPORT_SYMBOL(pwm_config);
+
+int pwm_enable(struct pwm_device *pwm)
+{
+ int rc = 0;
+
+ if (!pwm->clk_enabled) {
+ rc = clk_enable(pwm->clk);
+ if (!rc)
+ pwm->clk_enabled = 1;
+ }
+ return rc;
+}
+EXPORT_SYMBOL(pwm_enable);
+
+void pwm_disable(struct pwm_device *pwm)
+{
+ if (pwm->clk_enabled) {
+ clk_disable(pwm->clk);
+ pwm->clk_enabled = 0;
+ }
+}
+EXPORT_SYMBOL(pwm_disable);
+
+static DEFINE_MUTEX(pwm_lock);
+static LIST_HEAD(pwm_list);
+
+struct pwm_device *pwm_request(int pwm_id, const char *label)
+{
+ struct pwm_device *pwm;
+ int found = 0;
+
+ mutex_lock(&pwm_lock);
+
+ list_for_each_entry(pwm, &pwm_list, node) {
+ if (pwm->pwm_id == pwm_id) {
+ found = 1;
+ break;
+ }
+ }
+
+ if (found) {
+ if (pwm->use_count == 0) {
+ pwm->use_count++;
+ pwm->label = label;
+ } else
+ pwm = ERR_PTR(-EBUSY);
+ } else
+ pwm = ERR_PTR(-ENOENT);
+
+ mutex_unlock(&pwm_lock);
+ return pwm;
+}
+EXPORT_SYMBOL(pwm_request);
+
+void pwm_free(struct pwm_device *pwm)
+{
+ mutex_lock(&pwm_lock);
+
+ if (pwm->use_count) {
+ pwm->use_count--;
+ pwm->label = NULL;
+ } else
+ pr_warning("PWM device already freed\n");
+
+ mutex_unlock(&pwm_lock);
+}
+EXPORT_SYMBOL(pwm_free);
+
+static int __devinit mxc_pwm_probe(struct platform_device *pdev)
+{
+ struct pwm_device *pwm;
+ struct resource *r;
+ int ret = 0;
+
+ pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL);
+ if (pwm == NULL) {
+ dev_err(&pdev->dev, "failed to allocate memory\n");
+ return -ENOMEM;
+ }
+
+ pwm->clk = clk_get(&pdev->dev, "pwm");
+
+ if (IS_ERR(pwm->clk)) {
+ ret = PTR_ERR(pwm->clk);
+ goto err_free;
+ }
+
+ pwm->clk_enabled = 0;
+
+ pwm->use_count = 0;
+ pwm->pwm_id = pdev->id;
+ pwm->pdev = pdev;
+
+ 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, r->end - r->start + 1, 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, r->end - r->start + 1);
+ if (pwm->mmio_base == NULL) {
+ dev_err(&pdev->dev, "failed to ioremap() registers\n");
+ ret = -ENODEV;
+ goto err_free_mem;
+ }
+
+ mutex_lock(&pwm_lock);
+ list_add_tail(&pwm->node, &pwm_list);
+ mutex_unlock(&pwm_lock);
+
+ platform_set_drvdata(pdev, pwm);
+ return 0;
+
+err_free_mem:
+ release_mem_region(r->start, r->end - r->start + 1);
+err_free_clk:
+ clk_put(pwm->clk);
+err_free:
+ kfree(pwm);
+ return ret;
+}
+
+static int __devexit mxc_pwm_remove(struct platform_device *pdev)
+{
+ struct pwm_device *pwm;
+ struct resource *r;
+
+ pwm = platform_get_drvdata(pdev);
+ if (pwm == NULL)
+ return -ENODEV;
+
+ mutex_lock(&pwm_lock);
+ list_del(&pwm->node);
+ mutex_unlock(&pwm_lock);
+
+ iounmap(pwm->mmio_base);
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ release_mem_region(r->start, r->end - r->start + 1);
+
+ clk_put(pwm->clk);
+
+ kfree(pwm);
+ return 0;
+}
+
+static struct platform_driver mxc_pwm_driver = {
+ .driver = {
+ .name = "mxc_pwm",
+ },
+ .probe = mxc_pwm_probe,
+ .remove = __devexit_p(mxc_pwm_remove),
+};
+
+static int __init mxc_pwm_init(void)
+{
+ return platform_driver_register(&mxc_pwm_driver);
+}
+arch_initcall(mxc_pwm_init);
+
+static void __exit mxc_pwm_exit(void)
+{
+ platform_driver_unregister(&mxc_pwm_driver);
+}
+module_exit(mxc_pwm_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
+
projects / linux-2.6-microblaze.git / commitdiff