diff options
Diffstat (limited to 'arch/unicore32/kernel/pwm.c')
| -rw-r--r-- | arch/unicore32/kernel/pwm.c | 263 |
1 files changed, 0 insertions, 263 deletions
diff --git a/arch/unicore32/kernel/pwm.c b/arch/unicore32/kernel/pwm.c deleted file mode 100644 index 4615d51e3ba6..000000000000 --- a/arch/unicore32/kernel/pwm.c +++ /dev/null @@ -1,263 +0,0 @@ -/* - * linux/arch/unicore32/kernel/pwm.c - * - * Code specific to PKUnity SoC and UniCore ISA - * - * Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn> - * Copyright (C) 2001-2010 Guan Xuetao - * - * 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. - */ - -#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> -#include <mach/hardware.h> - -struct pwm_device { - struct list_head node; - struct platform_device *pdev; - - const char *label; - struct clk *clk; - int clk_enabled; - - unsigned int use_count; - unsigned int pwm_id; -}; - -/* - * period_ns = 10^9 * (PRESCALE + 1) * (PV + 1) / PWM_CLK_RATE - * duty_ns = 10^9 * (PRESCALE + 1) * DC / PWM_CLK_RATE - */ -int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns) -{ - unsigned long long c; - unsigned long period_cycles, prescale, pv, dc; - - 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; - - 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 = OST_PWMDCCR_FDCYCLE; - else - dc = (pv + 1) * duty_ns / period_ns; - - /* NOTE: the clock to PWM has to be enabled first - * before writing to the registers - */ - clk_enable(pwm->clk); - OST_PWMPWCR = prescale; - OST_PWMDCCR = pv - dc; - OST_PWMPCR = pv; - clk_disable(pwm->clk); - - 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 inline void __add_pwm(struct pwm_device *pwm) -{ - mutex_lock(&pwm_lock); - list_add_tail(&pwm->node, &pwm_list); - mutex_unlock(&pwm_lock); -} - -static struct pwm_device *pwm_probe(struct platform_device *pdev, - unsigned int pwm_id, struct pwm_device *parent_pwm) -{ - 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 ERR_PTR(-ENOMEM); - } - - pwm->clk = clk_get(NULL, "OST_CLK"); - if (IS_ERR(pwm->clk)) { - ret = PTR_ERR(pwm->clk); - goto err_free; - } - pwm->clk_enabled = 0; - - pwm->use_count = 0; - pwm->pwm_id = pwm_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, resource_size(r), pdev->name); - if (r == NULL) { - dev_err(&pdev->dev, "failed to request memory resource\n"); - ret = -EBUSY; - goto err_free_clk; - } - - __add_pwm(pwm); - platform_set_drvdata(pdev, pwm); - return pwm; - -err_free_clk: - clk_put(pwm->clk); -err_free: - kfree(pwm); - return ERR_PTR(ret); -} - -static int __devinit puv3_pwm_probe(struct platform_device *pdev) -{ - struct pwm_device *pwm = pwm_probe(pdev, pdev->id, NULL); - - if (IS_ERR(pwm)) - return PTR_ERR(pwm); - - return 0; -} - -static int __devexit 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); - - r = platform_get_resource(pdev, IORESOURCE_MEM, 0); - release_mem_region(r->start, resource_size(r)); - - clk_put(pwm->clk); - kfree(pwm); - return 0; -} - -static struct platform_driver puv3_pwm_driver = { - .driver = { - .name = "PKUnity-v3-PWM", - }, - .probe = puv3_pwm_probe, - .remove = __devexit_p(pwm_remove), -}; - -static int __init pwm_init(void) -{ - int ret = 0; - - ret = platform_driver_register(&puv3_pwm_driver); - if (ret) { - printk(KERN_ERR "failed to register puv3_pwm_driver\n"); - return ret; - } - - return ret; -} -arch_initcall(pwm_init); - -static void __exit pwm_exit(void) -{ - platform_driver_unregister(&puv3_pwm_driver); -} -module_exit(pwm_exit); - -MODULE_LICENSE("GPL v2"); |