| /* |
| * Simple PWM driver for EP93XX |
| * |
| * (c) Copyright 2009 Matthieu Crapet <mcrapet@gmail.com> |
| * (c) Copyright 2009 H Hartley Sweeten <hsweeten@visionengravers.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; either version |
| * 2 of the License, or (at your option) any later version. |
| * |
| * EP9307 has only one channel: |
| * - PWMOUT |
| * |
| * EP9301/02/12/15 have two channels: |
| * - PWMOUT |
| * - PWMOUT1 (alternate function for EGPIO14) |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/platform_device.h> |
| #include <linux/slab.h> |
| #include <linux/clk.h> |
| #include <linux/err.h> |
| #include <linux/io.h> |
| |
| #include <mach/platform.h> |
| |
| #define EP93XX_PWMx_TERM_COUNT 0x00 |
| #define EP93XX_PWMx_DUTY_CYCLE 0x04 |
| #define EP93XX_PWMx_ENABLE 0x08 |
| #define EP93XX_PWMx_INVERT 0x0C |
| |
| #define EP93XX_PWM_MAX_COUNT 0xFFFF |
| |
| struct ep93xx_pwm { |
| void __iomem *mmio_base; |
| struct clk *clk; |
| u32 duty_percent; |
| }; |
| |
| static inline void ep93xx_pwm_writel(struct ep93xx_pwm *pwm, |
| unsigned int val, unsigned int off) |
| { |
| __raw_writel(val, pwm->mmio_base + off); |
| } |
| |
| static inline unsigned int ep93xx_pwm_readl(struct ep93xx_pwm *pwm, |
| unsigned int off) |
| { |
| return __raw_readl(pwm->mmio_base + off); |
| } |
| |
| static inline void ep93xx_pwm_write_tc(struct ep93xx_pwm *pwm, u16 value) |
| { |
| ep93xx_pwm_writel(pwm, value, EP93XX_PWMx_TERM_COUNT); |
| } |
| |
| static inline u16 ep93xx_pwm_read_tc(struct ep93xx_pwm *pwm) |
| { |
| return ep93xx_pwm_readl(pwm, EP93XX_PWMx_TERM_COUNT); |
| } |
| |
| static inline void ep93xx_pwm_write_dc(struct ep93xx_pwm *pwm, u16 value) |
| { |
| ep93xx_pwm_writel(pwm, value, EP93XX_PWMx_DUTY_CYCLE); |
| } |
| |
| static inline void ep93xx_pwm_enable(struct ep93xx_pwm *pwm) |
| { |
| ep93xx_pwm_writel(pwm, 0x1, EP93XX_PWMx_ENABLE); |
| } |
| |
| static inline void ep93xx_pwm_disable(struct ep93xx_pwm *pwm) |
| { |
| ep93xx_pwm_writel(pwm, 0x0, EP93XX_PWMx_ENABLE); |
| } |
| |
| static inline int ep93xx_pwm_is_enabled(struct ep93xx_pwm *pwm) |
| { |
| return ep93xx_pwm_readl(pwm, EP93XX_PWMx_ENABLE) & 0x1; |
| } |
| |
| static inline void ep93xx_pwm_invert(struct ep93xx_pwm *pwm) |
| { |
| ep93xx_pwm_writel(pwm, 0x1, EP93XX_PWMx_INVERT); |
| } |
| |
| static inline void ep93xx_pwm_normal(struct ep93xx_pwm *pwm) |
| { |
| ep93xx_pwm_writel(pwm, 0x0, EP93XX_PWMx_INVERT); |
| } |
| |
| static inline int ep93xx_pwm_is_inverted(struct ep93xx_pwm *pwm) |
| { |
| return ep93xx_pwm_readl(pwm, EP93XX_PWMx_INVERT) & 0x1; |
| } |
| |
| /* |
| * /sys/devices/platform/ep93xx-pwm.N |
| * /min_freq read-only minimum pwm output frequency |
| * /max_req read-only maximum pwm output frequency |
| * /freq read-write pwm output frequency (0 = disable output) |
| * /duty_percent read-write pwm duty cycle percent (1..99) |
| * /invert read-write invert pwm output |
| */ |
| |
| static ssize_t ep93xx_pwm_get_min_freq(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct platform_device *pdev = to_platform_device(dev); |
| struct ep93xx_pwm *pwm = platform_get_drvdata(pdev); |
| unsigned long rate = clk_get_rate(pwm->clk); |
| |
| return sprintf(buf, "%ld\n", rate / (EP93XX_PWM_MAX_COUNT + 1)); |
| } |
| |
| static ssize_t ep93xx_pwm_get_max_freq(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct platform_device *pdev = to_platform_device(dev); |
| struct ep93xx_pwm *pwm = platform_get_drvdata(pdev); |
| unsigned long rate = clk_get_rate(pwm->clk); |
| |
| return sprintf(buf, "%ld\n", rate / 2); |
| } |
| |
| static ssize_t ep93xx_pwm_get_freq(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct platform_device *pdev = to_platform_device(dev); |
| struct ep93xx_pwm *pwm = platform_get_drvdata(pdev); |
| |
| if (ep93xx_pwm_is_enabled(pwm)) { |
| unsigned long rate = clk_get_rate(pwm->clk); |
| u16 term = ep93xx_pwm_read_tc(pwm); |
| |
| return sprintf(buf, "%ld\n", rate / (term + 1)); |
| } else { |
| return sprintf(buf, "disabled\n"); |
| } |
| } |
| |
| static ssize_t ep93xx_pwm_set_freq(struct device *dev, |
| struct device_attribute *attr, const char *buf, size_t count) |
| { |
| struct platform_device *pdev = to_platform_device(dev); |
| struct ep93xx_pwm *pwm = platform_get_drvdata(pdev); |
| long val; |
| int err; |
| |
| err = strict_strtol(buf, 10, &val); |
| if (err) |
| return -EINVAL; |
| |
| if (val == 0) { |
| ep93xx_pwm_disable(pwm); |
| } else if (val <= (clk_get_rate(pwm->clk) / 2)) { |
| u32 term, duty; |
| |
| val = (clk_get_rate(pwm->clk) / val) - 1; |
| if (val > EP93XX_PWM_MAX_COUNT) |
| val = EP93XX_PWM_MAX_COUNT; |
| if (val < 1) |
| val = 1; |
| |
| term = ep93xx_pwm_read_tc(pwm); |
| duty = ((val + 1) * pwm->duty_percent / 100) - 1; |
| |
| /* If pwm is running, order is important */ |
| if (val > term) { |
| ep93xx_pwm_write_tc(pwm, val); |
| ep93xx_pwm_write_dc(pwm, duty); |
| } else { |
| ep93xx_pwm_write_dc(pwm, duty); |
| ep93xx_pwm_write_tc(pwm, val); |
| } |
| |
| if (!ep93xx_pwm_is_enabled(pwm)) |
| ep93xx_pwm_enable(pwm); |
| } else { |
| return -EINVAL; |
| } |
| |
| return count; |
| } |
| |
| static ssize_t ep93xx_pwm_get_duty_percent(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct platform_device *pdev = to_platform_device(dev); |
| struct ep93xx_pwm *pwm = platform_get_drvdata(pdev); |
| |
| return sprintf(buf, "%d\n", pwm->duty_percent); |
| } |
| |
| static ssize_t ep93xx_pwm_set_duty_percent(struct device *dev, |
| struct device_attribute *attr, const char *buf, size_t count) |
| { |
| struct platform_device *pdev = to_platform_device(dev); |
| struct ep93xx_pwm *pwm = platform_get_drvdata(pdev); |
| long val; |
| int err; |
| |
| err = strict_strtol(buf, 10, &val); |
| if (err) |
| return -EINVAL; |
| |
| if (val > 0 && val < 100) { |
| u32 term = ep93xx_pwm_read_tc(pwm); |
| ep93xx_pwm_write_dc(pwm, ((term + 1) * val / 100) - 1); |
| pwm->duty_percent = val; |
| return count; |
| } |
| |
| return -EINVAL; |
| } |
| |
| static ssize_t ep93xx_pwm_get_invert(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct platform_device *pdev = to_platform_device(dev); |
| struct ep93xx_pwm *pwm = platform_get_drvdata(pdev); |
| |
| return sprintf(buf, "%d\n", ep93xx_pwm_is_inverted(pwm)); |
| } |
| |
| static ssize_t ep93xx_pwm_set_invert(struct device *dev, |
| struct device_attribute *attr, const char *buf, size_t count) |
| { |
| struct platform_device *pdev = to_platform_device(dev); |
| struct ep93xx_pwm *pwm = platform_get_drvdata(pdev); |
| long val; |
| int err; |
| |
| err = strict_strtol(buf, 10, &val); |
| if (err) |
| return -EINVAL; |
| |
| if (val == 0) |
| ep93xx_pwm_normal(pwm); |
| else if (val == 1) |
| ep93xx_pwm_invert(pwm); |
| else |
| return -EINVAL; |
| |
| return count; |
| } |
| |
| static DEVICE_ATTR(min_freq, S_IRUGO, ep93xx_pwm_get_min_freq, NULL); |
| static DEVICE_ATTR(max_freq, S_IRUGO, ep93xx_pwm_get_max_freq, NULL); |
| static DEVICE_ATTR(freq, S_IWUSR | S_IRUGO, |
| ep93xx_pwm_get_freq, ep93xx_pwm_set_freq); |
| static DEVICE_ATTR(duty_percent, S_IWUSR | S_IRUGO, |
| ep93xx_pwm_get_duty_percent, ep93xx_pwm_set_duty_percent); |
| static DEVICE_ATTR(invert, S_IWUSR | S_IRUGO, |
| ep93xx_pwm_get_invert, ep93xx_pwm_set_invert); |
| |
| static struct attribute *ep93xx_pwm_attrs[] = { |
| &dev_attr_min_freq.attr, |
| &dev_attr_max_freq.attr, |
| &dev_attr_freq.attr, |
| &dev_attr_duty_percent.attr, |
| &dev_attr_invert.attr, |
| NULL |
| }; |
| |
| static const struct attribute_group ep93xx_pwm_sysfs_files = { |
| .attrs = ep93xx_pwm_attrs, |
| }; |
| |
| static int __init ep93xx_pwm_probe(struct platform_device *pdev) |
| { |
| struct ep93xx_pwm *pwm; |
| struct resource *res; |
| int err; |
| |
| err = ep93xx_pwm_acquire_gpio(pdev); |
| if (err) |
| return err; |
| |
| pwm = kzalloc(sizeof(struct ep93xx_pwm), GFP_KERNEL); |
| if (!pwm) { |
| err = -ENOMEM; |
| goto fail_no_mem; |
| } |
| |
| res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| if (res == NULL) { |
| err = -ENXIO; |
| goto fail_no_mem_resource; |
| } |
| |
| res = request_mem_region(res->start, resource_size(res), pdev->name); |
| if (res == NULL) { |
| err = -EBUSY; |
| goto fail_no_mem_resource; |
| } |
| |
| pwm->mmio_base = ioremap(res->start, resource_size(res)); |
| if (pwm->mmio_base == NULL) { |
| err = -ENXIO; |
| goto fail_no_ioremap; |
| } |
| |
| err = sysfs_create_group(&pdev->dev.kobj, &ep93xx_pwm_sysfs_files); |
| if (err) |
| goto fail_no_sysfs; |
| |
| pwm->clk = clk_get(&pdev->dev, "pwm_clk"); |
| if (IS_ERR(pwm->clk)) { |
| err = PTR_ERR(pwm->clk); |
| goto fail_no_clk; |
| } |
| |
| pwm->duty_percent = 50; |
| |
| platform_set_drvdata(pdev, pwm); |
| |
| /* disable pwm at startup. Avoids zero value. */ |
| ep93xx_pwm_disable(pwm); |
| ep93xx_pwm_write_tc(pwm, EP93XX_PWM_MAX_COUNT); |
| ep93xx_pwm_write_dc(pwm, EP93XX_PWM_MAX_COUNT / 2); |
| |
| clk_enable(pwm->clk); |
| |
| return 0; |
| |
| fail_no_clk: |
| sysfs_remove_group(&pdev->dev.kobj, &ep93xx_pwm_sysfs_files); |
| fail_no_sysfs: |
| iounmap(pwm->mmio_base); |
| fail_no_ioremap: |
| release_mem_region(res->start, resource_size(res)); |
| fail_no_mem_resource: |
| kfree(pwm); |
| fail_no_mem: |
| ep93xx_pwm_release_gpio(pdev); |
| return err; |
| } |
| |
| static int __exit ep93xx_pwm_remove(struct platform_device *pdev) |
| { |
| struct ep93xx_pwm *pwm = platform_get_drvdata(pdev); |
| struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| |
| ep93xx_pwm_disable(pwm); |
| clk_disable(pwm->clk); |
| clk_put(pwm->clk); |
| platform_set_drvdata(pdev, NULL); |
| sysfs_remove_group(&pdev->dev.kobj, &ep93xx_pwm_sysfs_files); |
| iounmap(pwm->mmio_base); |
| release_mem_region(res->start, resource_size(res)); |
| kfree(pwm); |
| ep93xx_pwm_release_gpio(pdev); |
| |
| return 0; |
| } |
| |
| static struct platform_driver ep93xx_pwm_driver = { |
| .driver = { |
| .name = "ep93xx-pwm", |
| .owner = THIS_MODULE, |
| }, |
| .remove = __exit_p(ep93xx_pwm_remove), |
| }; |
| |
| static int __init ep93xx_pwm_init(void) |
| { |
| return platform_driver_probe(&ep93xx_pwm_driver, ep93xx_pwm_probe); |
| } |
| |
| static void __exit ep93xx_pwm_exit(void) |
| { |
| platform_driver_unregister(&ep93xx_pwm_driver); |
| } |
| |
| module_init(ep93xx_pwm_init); |
| module_exit(ep93xx_pwm_exit); |
| |
| MODULE_AUTHOR("Matthieu Crapet <mcrapet@gmail.com>, " |
| "H Hartley Sweeten <hsweeten@visionengravers.com>"); |
| MODULE_DESCRIPTION("EP93xx PWM driver"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS("platform:ep93xx-pwm"); |