From 29693248edf10830db2ef82b36806e378ff75c67 Mon Sep 17 00:00:00 2001 From: Sascha Hauer Date: Thu, 15 Mar 2012 10:04:35 +0100 Subject: ARM i.MX: Move i.MX pwm driver to pwm framework MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Move the driver to drivers/pwm/ and convert it to use the framework. Signed-off-by: Sascha Hauer [eric@eukrea.com: set chip.dev to prevent probe failure] [eric@eukrea.com: fix pwmchip_add return code test] Signed-off-by: Eric Bénard Signed-off-by: Thierry Reding diff --git a/arch/arm/plat-mxc/Kconfig b/arch/arm/plat-mxc/Kconfig index c722f9c..baf9064 100644 --- a/arch/arm/plat-mxc/Kconfig +++ b/arch/arm/plat-mxc/Kconfig @@ -47,12 +47,6 @@ config MXC_TZIC config MXC_AVIC bool -config MXC_PWM - tristate "Enable PWM driver" - select HAVE_PWM - help - Enable support for the i.MX PWM controller(s). - config MXC_DEBUG_BOARD bool "Enable MXC debug board(for 3-stack)" help diff --git a/arch/arm/plat-mxc/Makefile b/arch/arm/plat-mxc/Makefile index e81290c..46ba8de 100644 --- a/arch/arm/plat-mxc/Makefile +++ b/arch/arm/plat-mxc/Makefile @@ -11,7 +11,6 @@ obj-$(CONFIG_MXC_AVIC) += avic.o obj-$(CONFIG_IMX_HAVE_IOMUX_V1) += iomux-v1.o obj-$(CONFIG_ARCH_MXC_IOMUX_V3) += iomux-v3.o obj-$(CONFIG_IRAM_ALLOC) += iram_alloc.o -obj-$(CONFIG_MXC_PWM) += pwm.o obj-$(CONFIG_MXC_ULPI) += ulpi.o obj-$(CONFIG_MXC_USE_EPIT) += epit.o obj-$(CONFIG_MXC_DEBUG_BOARD) += 3ds_debugboard.o diff --git a/arch/arm/plat-mxc/pwm.c b/arch/arm/plat-mxc/pwm.c deleted file mode 100644 index c0cab22..0000000 --- a/arch/arm/plat-mxc/pwm.c +++ /dev/null @@ -1,306 +0,0 @@ -/* - * 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 - */ - -#include -#include -#include -#include -#include -#include -#include -#include -#include - - -/* i.MX1 and i.MX21 share the same PWM function block: */ - -#define MX1_PWMC 0x00 /* PWM Control Register */ -#define MX1_PWMS 0x04 /* PWM Sample Register */ -#define MX1_PWMP 0x08 /* PWM Period Register */ - - -/* i.MX27, i.MX31, i.MX35 share the same PWM function block: */ - -#define MX3_PWMCR 0x00 /* PWM Control Register */ -#define MX3_PWMSAR 0x0C /* PWM Sample Register */ -#define MX3_PWMPR 0x10 /* PWM Period Register */ -#define MX3_PWMCR_PRESCALER(x) (((x - 1) & 0xFFF) << 4) -#define MX3_PWMCR_DOZEEN (1 << 24) -#define MX3_PWMCR_WAITEN (1 << 23) -#define MX3_PWMCR_DBGEN (1 << 22) -#define MX3_PWMCR_CLKSRC_IPG_HIGH (2 << 16) -#define MX3_PWMCR_CLKSRC_IPG (1 << 16) -#define MX3_PWMCR_EN (1 << 0) - - - -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) -{ - if (pwm == NULL || period_ns == 0 || duty_ns > period_ns) - return -EINVAL; - - if (!(cpu_is_mx1() || cpu_is_mx21())) { - unsigned long long c; - unsigned long period_cycles, duty_cycles, prescale; - u32 cr; - - 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; - - /* - * according to imx pwm RM, the real period value should be - * PERIOD value in PWMPR plus 2. - */ - if (period_cycles > 2) - period_cycles -= 2; - else - period_cycles = 0; - - writel(duty_cycles, pwm->mmio_base + MX3_PWMSAR); - writel(period_cycles, pwm->mmio_base + MX3_PWMPR); - - cr = MX3_PWMCR_PRESCALER(prescale) | - MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN | - MX3_PWMCR_DBGEN | MX3_PWMCR_EN; - - if (cpu_is_mx25()) - cr |= MX3_PWMCR_CLKSRC_IPG; - else - cr |= MX3_PWMCR_CLKSRC_IPG_HIGH; - - writel(cr, pwm->mmio_base + MX3_PWMCR); - } else if (cpu_is_mx1() || cpu_is_mx21()) { - /* The PWM subsystem allows for exact frequencies. However, - * I cannot connect a scope on my device to the PWM line and - * thus cannot provide the program the PWM controller - * exactly. Instead, I'm relying on the fact that the - * Bootloader (u-boot or WinCE+haret) has programmed the PWM - * function group already. So I'll just modify the PWM sample - * register to follow the ratio of duty_ns vs. period_ns - * accordingly. - * - * This is good enough for programming the brightness of - * the LCD backlight. - * - * The real implementation would divide PERCLK[0] first by - * both the prescaler (/1 .. /128) and then by CLKSEL - * (/2 .. /16). - */ - u32 max = readl(pwm->mmio_base + MX1_PWMP); - u32 p = max * duty_ns / period_ns; - writel(max - p, pwm->mmio_base + MX1_PWMS); - } else { - BUG(); - } - - return 0; -} -EXPORT_SYMBOL(pwm_config); - -int pwm_enable(struct pwm_device *pwm) -{ - int rc = 0; - - if (!pwm->clk_enabled) { - rc = clk_prepare_enable(pwm->clk); - if (!rc) - pwm->clk_enabled = 1; - } - return rc; -} -EXPORT_SYMBOL(pwm_enable); - -void pwm_disable(struct pwm_device *pwm) -{ - writel(0, pwm->mmio_base + MX3_PWMCR); - - if (pwm->clk_enabled) { - clk_disable_unprepare(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, 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; - } - - 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, resource_size(r)); -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, resource_size(r)); - - 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 "); diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index 0ef4f30..a9a9715 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -18,6 +18,15 @@ config PWM_BFIN To compile this driver as a module, choose M here: the module will be called pwm-bfin. +config PWM_IMX + tristate "i.MX pwm support" + depends on ARCH_MXC + help + Generic PWM framework driver for i.MX. + + To compile this driver as a module, choose M here: the module + will be called pwm-imx. + config PWM_PXA tristate "PXA PWM support" depends on ARCH_PXA diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index e859c51..3dd1b83 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -1,4 +1,5 @@ obj-$(CONFIG_PWM) += core.o obj-$(CONFIG_PWM_BFIN) += pwm-bfin.o +obj-$(CONFIG_PWM_IMX) += pwm-imx.o obj-$(CONFIG_PWM_PXA) += pwm-pxa.o obj-$(CONFIG_PWM_TEGRA) += pwm-tegra.o diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c new file mode 100644 index 0000000..900d145 --- /dev/null +++ b/drivers/pwm/pwm-imx.c @@ -0,0 +1,267 @@ +/* + * 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 + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + + +/* i.MX1 and i.MX21 share the same PWM function block: */ + +#define MX1_PWMC 0x00 /* PWM Control Register */ +#define MX1_PWMS 0x04 /* PWM Sample Register */ +#define MX1_PWMP 0x08 /* PWM Period Register */ + + +/* i.MX27, i.MX31, i.MX35 share the same PWM function block: */ + +#define MX3_PWMCR 0x00 /* PWM Control Register */ +#define MX3_PWMSAR 0x0C /* PWM Sample Register */ +#define MX3_PWMPR 0x10 /* PWM Period Register */ +#define MX3_PWMCR_PRESCALER(x) (((x - 1) & 0xFFF) << 4) +#define MX3_PWMCR_DOZEEN (1 << 24) +#define MX3_PWMCR_WAITEN (1 << 23) +#define MX3_PWMCR_DBGEN (1 << 22) +#define MX3_PWMCR_CLKSRC_IPG_HIGH (2 << 16) +#define MX3_PWMCR_CLKSRC_IPG (1 << 16) +#define MX3_PWMCR_EN (1 << 0) + +struct imx_chip { + struct clk *clk; + + int clk_enabled; + void __iomem *mmio_base; + + struct pwm_chip chip; +}; + +#define to_imx_chip(chip) container_of(chip, struct imx_chip, chip) + +static int imx_pwm_config(struct pwm_chip *chip, + struct pwm_device *pwm, int duty_ns, int period_ns) +{ + struct imx_chip *imx = to_imx_chip(chip); + + if (!(cpu_is_mx1() || cpu_is_mx21())) { + unsigned long long c; + unsigned long period_cycles, duty_cycles, prescale; + u32 cr; + + c = clk_get_rate(imx->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; + + /* + * according to imx pwm RM, the real period value should be + * PERIOD value in PWMPR plus 2. + */ + if (period_cycles > 2) + period_cycles -= 2; + else + period_cycles = 0; + + writel(duty_cycles, imx->mmio_base + MX3_PWMSAR); + writel(period_cycles, imx->mmio_base + MX3_PWMPR); + + cr = MX3_PWMCR_PRESCALER(prescale) | + MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN | + MX3_PWMCR_DBGEN | MX3_PWMCR_EN; + + if (cpu_is_mx25()) + cr |= MX3_PWMCR_CLKSRC_IPG; + else + cr |= MX3_PWMCR_CLKSRC_IPG_HIGH; + + writel(cr, imx->mmio_base + MX3_PWMCR); + } else if (cpu_is_mx1() || cpu_is_mx21()) { + /* The PWM subsystem allows for exact frequencies. However, + * I cannot connect a scope on my device to the PWM line and + * thus cannot provide the program the PWM controller + * exactly. Instead, I'm relying on the fact that the + * Bootloader (u-boot or WinCE+haret) has programmed the PWM + * function group already. So I'll just modify the PWM sample + * register to follow the ratio of duty_ns vs. period_ns + * accordingly. + * + * This is good enough for programming the brightness of + * the LCD backlight. + * + * The real implementation would divide PERCLK[0] first by + * both the prescaler (/1 .. /128) and then by CLKSEL + * (/2 .. /16). + */ + u32 max = readl(imx->mmio_base + MX1_PWMP); + u32 p = max * duty_ns / period_ns; + writel(max - p, imx->mmio_base + MX1_PWMS); + } else { + BUG(); + } + + return 0; +} + +static int imx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct imx_chip *imx = to_imx_chip(chip); + int rc = 0; + + if (!imx->clk_enabled) { + rc = clk_prepare_enable(imx->clk); + if (!rc) + imx->clk_enabled = 1; + } + return rc; +} + +static void imx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct imx_chip *imx = to_imx_chip(chip); + + writel(0, imx->mmio_base + MX3_PWMCR); + + if (imx->clk_enabled) { + clk_disable_unprepare(imx->clk); + imx->clk_enabled = 0; + } +} + +static struct pwm_ops imx_pwm_ops = { + .enable = imx_pwm_enable, + .disable = imx_pwm_disable, + .config = imx_pwm_config, + .owner = THIS_MODULE, +}; + +static int __devinit imx_pwm_probe(struct platform_device *pdev) +{ + struct imx_chip *imx; + struct resource *r; + int ret = 0; + + imx = kzalloc(sizeof(*imx), GFP_KERNEL); + if (imx == NULL) { + dev_err(&pdev->dev, "failed to allocate memory\n"); + return -ENOMEM; + } + + imx->clk = clk_get(&pdev->dev, "pwm"); + + if (IS_ERR(imx->clk)) { + ret = PTR_ERR(imx->clk); + goto err_free; + } + + imx->chip.ops = &imx_pwm_ops; + imx->chip.dev = &pdev->dev; + imx->chip.base = -1; + imx->chip.npwm = 1; + + imx->clk_enabled = 0; + + 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; + } + + imx->mmio_base = ioremap(r->start, resource_size(r)); + if (imx->mmio_base == NULL) { + dev_err(&pdev->dev, "failed to ioremap() registers\n"); + ret = -ENODEV; + goto err_free_mem; + } + + ret = pwmchip_add(&imx->chip); + if (ret < 0) + goto err_iounmap; + + platform_set_drvdata(pdev, imx); + return 0; + +err_iounmap: + iounmap(imx->mmio_base); +err_free_mem: + release_mem_region(r->start, resource_size(r)); +err_free_clk: + clk_put(imx->clk); +err_free: + kfree(imx); + return ret; +} + +static int __devexit imx_pwm_remove(struct platform_device *pdev) +{ + struct imx_chip *imx; + struct resource *r; + int ret; + + imx = platform_get_drvdata(pdev); + if (imx == NULL) + return -ENODEV; + + ret = pwmchip_remove(&imx->chip); + if (ret) + return ret; + + iounmap(imx->mmio_base); + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + release_mem_region(r->start, resource_size(r)); + + clk_put(imx->clk); + + kfree(imx); + return 0; +} + +static struct platform_driver imx_pwm_driver = { + .driver = { + .name = "mxc_pwm", + }, + .probe = imx_pwm_probe, + .remove = __devexit_p(imx_pwm_remove), +}; + +static int __init imx_pwm_init(void) +{ + return platform_driver_register(&imx_pwm_driver); +} +arch_initcall(imx_pwm_init); + +static void __exit imx_pwm_exit(void) +{ + platform_driver_unregister(&imx_pwm_driver); +} +module_exit(imx_pwm_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Sascha Hauer "); -- cgit v0.10.2