From: eric miao Date: Sun, 13 Apr 2008 20:44:04 +0000 (+0100) Subject: [ARM] pxa: Add PXA support for PWM API X-Git-Tag: v2.6.27-rc1~1095^2^2~7^2~11 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=75540c1ac3c7bd72ac8e092058f9714875239995;p=linux-2.6 [ARM] pxa: Add PXA support for PWM API Patch mainly from Eric Miao, with minor edits by rmk. Note: PWM0 and PWM2 share the same register I/O space and clock gating on pxa{27x, 3xx}, thus PWM2 is treated in the driver as a child PWM of PWM0. And this is also true for PWM1/3. Signed-off-by: eric miao Signed-off-by: Russell King --- diff --git a/arch/arm/mach-pxa/Kconfig b/arch/arm/mach-pxa/Kconfig index 5da7a68204..9c01505b18 100644 --- a/arch/arm/mach-pxa/Kconfig +++ b/arch/arm/mach-pxa/Kconfig @@ -273,4 +273,9 @@ config PXA_SSP tristate help Enable support for PXA2xx SSP ports + +config PXA_PWM + tristate + help + Enable support for PXA2xx/PXA3xx PWM controllers endif diff --git a/arch/arm/mach-pxa/Makefile b/arch/arm/mach-pxa/Makefile index 0e6d05bb81..02cbc3cfbe 100644 --- a/arch/arm/mach-pxa/Makefile +++ b/arch/arm/mach-pxa/Makefile @@ -10,6 +10,7 @@ obj-$(CONFIG_CPU_FREQ) += cpu-pxa.o # Generic drivers that other drivers may depend upon obj-$(CONFIG_PXA_SSP) += ssp.o +obj-$(CONFIG_PXA_PWM) += pwm.o # SoC-specific code obj-$(CONFIG_PXA25x) += mfp-pxa2xx.o pxa25x.o diff --git a/arch/arm/mach-pxa/devices.c b/arch/arm/mach-pxa/devices.c index d6c05b6eab..794a1076db 100644 --- a/arch/arm/mach-pxa/devices.c +++ b/arch/arm/mach-pxa/devices.c @@ -280,6 +280,36 @@ struct platform_device pxa_device_rtc = { #ifdef CONFIG_PXA25x +static struct resource pxa25x_resource_pwm0[] = { + [0] = { + .start = 0x40b00000, + .end = 0x40b0000f, + .flags = IORESOURCE_MEM, + }, +}; + +struct platform_device pxa25x_device_pwm0 = { + .name = "pxa25x-pwm", + .id = 0, + .resource = pxa25x_resource_pwm0, + .num_resources = ARRAY_SIZE(pxa25x_resource_pwm0), +}; + +static struct resource pxa25x_resource_pwm1[] = { + [0] = { + .start = 0x40c00000, + .end = 0x40c0000f, + .flags = IORESOURCE_MEM, + }, +}; + +struct platform_device pxa25x_device_pwm1 = { + .name = "pxa25x-pwm", + .id = 1, + .resource = pxa25x_resource_pwm1, + .num_resources = ARRAY_SIZE(pxa25x_resource_pwm1), +}; + static u64 pxa25x_ssp_dma_mask = DMA_BIT_MASK(32); static struct resource pxa25x_resource_ssp[] = { @@ -568,6 +598,36 @@ struct platform_device pxa27x_device_ssp3 = { .num_resources = ARRAY_SIZE(pxa27x_resource_ssp3), }; +static struct resource pxa27x_resource_pwm0[] = { + [0] = { + .start = 0x40b00000, + .end = 0x40b0001f, + .flags = IORESOURCE_MEM, + }, +}; + +struct platform_device pxa27x_device_pwm0 = { + .name = "pxa27x-pwm", + .id = 0, + .resource = pxa27x_resource_pwm0, + .num_resources = ARRAY_SIZE(pxa27x_resource_pwm0), +}; + +static struct resource pxa27x_resource_pwm1[] = { + [0] = { + .start = 0x40c00000, + .end = 0x40c0001f, + .flags = IORESOURCE_MEM, + }, +}; + +struct platform_device pxa27x_device_pwm1 = { + .name = "pxa27x-pwm", + .id = 1, + .resource = pxa27x_resource_pwm1, + .num_resources = ARRAY_SIZE(pxa27x_resource_pwm1), +}; + static struct resource pxa27x_resource_camera[] = { [0] = { .start = 0x50000000, diff --git a/arch/arm/mach-pxa/devices.h b/arch/arm/mach-pxa/devices.h index fcab017f27..e620a3373d 100644 --- a/arch/arm/mach-pxa/devices.h +++ b/arch/arm/mach-pxa/devices.h @@ -24,4 +24,9 @@ extern struct platform_device pxa27x_device_ssp2; extern struct platform_device pxa27x_device_ssp3; extern struct platform_device pxa3xx_device_ssp4; +extern struct platform_device pxa25x_device_pwm0; +extern struct platform_device pxa25x_device_pwm1; +extern struct platform_device pxa27x_device_pwm0; +extern struct platform_device pxa27x_device_pwm1; + void __init pxa_register_device(struct platform_device *dev, void *data); diff --git a/arch/arm/mach-pxa/pwm.c b/arch/arm/mach-pxa/pwm.c new file mode 100644 index 0000000000..70fb3ca6a0 --- /dev/null +++ b/arch/arm/mach-pxa/pwm.c @@ -0,0 +1,299 @@ +/* + * 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 + */ + +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +/* 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 pwm_device { + struct list_head node; + struct platform_device *pdev; + + const char *label; + struct clk *clk; + void __iomem *mmio_base; + + 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 < 0) + 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 + */ + clk_enable(pwm->clk); + __raw_writel(prescale, pwm->mmio_base + PWMCR); + __raw_writel(dc, pwm->mmio_base + PWMDCR); + __raw_writel(pv, pwm->mmio_base + PWMPCR); + clk_disable(pwm->clk); + + return 0; +} +EXPORT_SYMBOL(pwm_config); + +int pwm_enable(struct pwm_device *pwm) +{ + return clk_enable(pwm->clk); +} +EXPORT_SYMBOL(pwm_enable); + +void pwm_disable(struct pwm_device *pwm) +{ + clk_disable(pwm->clk); +} +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 && pwm->use_count == 0) { + pwm->use_count++; + pwm->label = label; + found = 1; + break; + } + } + + mutex_unlock(&pwm_lock); + + return (found) ? pwm : NULL; +} +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(&pdev->dev, "PWMCLK"); + if (IS_ERR(pwm->clk)) { + ret = PTR_ERR(pwm->clk); + goto err_free; + } + + pwm->use_count = 0; + pwm->pwm_id = pwm_id; + pwm->pdev = pdev; + + if (parent_pwm != NULL) { + /* registers for the second PWM has offset of 0x10 */ + pwm->mmio_base = parent_pwm->mmio_base + 0x10; + __add_pwm(pwm); + return pwm; + } + + 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; + } + + __add_pwm(pwm); + platform_set_drvdata(pdev, pwm); + return pwm; + +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 ERR_PTR(ret); +} + +static int __devinit pxa25x_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 __devinit pxa27x_pwm_probe(struct platform_device *pdev) +{ + struct pwm_device *pwm; + + pwm = pwm_probe(pdev, pdev->id * 2, NULL); + if (IS_ERR(pwm)) + return PTR_ERR(pwm); + + pwm = pwm_probe(pdev, pdev->id * 2 + 1, pwm); + 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); + + 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 pxa25x_pwm_driver = { + .driver = { + .name = "pxa25x-pwm", + }, + .probe = pxa25x_pwm_probe, + .remove = __devexit_p(pwm_remove), +}; + +static struct platform_driver pxa27x_pwm_driver = { + .driver = { + .name = "pxa27x-pwm", + }, + .probe = pxa27x_pwm_probe, + .remove = __devexit_p(pwm_remove), +}; + +static int __init pwm_init(void) +{ + int ret = 0; + + ret = platform_driver_register(&pxa25x_pwm_driver); + if (ret) { + printk(KERN_ERR "failed to register pxa25x_pwm_driver\n"); + return ret; + } + + ret = platform_driver_register(&pxa27x_pwm_driver); + if (ret) { + printk(KERN_ERR "failed to register pxa27x_pwm_driver\n"); + return ret; + } + + return ret; +} +arch_initcall(pwm_init); + +static void __exit pwm_exit(void) +{ + platform_driver_unregister(&pxa25x_pwm_driver); + platform_driver_unregister(&pxa27x_pwm_driver); +} +module_exit(pwm_exit); diff --git a/arch/arm/mach-pxa/pxa25x.c b/arch/arm/mach-pxa/pxa25x.c index e5b417d14b..2bed3f98d4 100644 --- a/arch/arm/mach-pxa/pxa25x.c +++ b/arch/arm/mach-pxa/pxa25x.c @@ -129,12 +129,12 @@ static struct clk pxa25x_clks[] = { INIT_CKEN("SSPCLK", SSP, 3686400, 0, &pxa25x_device_ssp.dev), INIT_CKEN("SSPCLK", NSSP, 3686400, 0, &pxa25x_device_nssp.dev), INIT_CKEN("SSPCLK", ASSP, 3686400, 0, &pxa25x_device_assp.dev), + INIT_CKEN("PWMCLK", PWM0, 3686400, 0, &pxa25x_device_pwm0.dev), + INIT_CKEN("PWMCLK", PWM1, 3686400, 0, &pxa25x_device_pwm1.dev), INIT_CKEN("AC97CLK", AC97, 24576000, 0, NULL), /* - INIT_CKEN("PWMCLK", PWM0, 3686400, 0, NULL), - INIT_CKEN("PWMCLK", PWM0, 3686400, 0, NULL), INIT_CKEN("I2SCLK", I2S, 14745600, 0, NULL), */ INIT_CKEN("FICPCLK", FICP, 47923000, 0, NULL), @@ -269,6 +269,8 @@ static struct platform_device *pxa25x_devices[] __initdata = { &pxa25x_device_ssp, &pxa25x_device_nssp, &pxa25x_device_assp, + &pxa25x_device_pwm0, + &pxa25x_device_pwm1, }; static struct sys_device pxa25x_sysdev[] = { diff --git a/arch/arm/mach-pxa/pxa27x.c b/arch/arm/mach-pxa/pxa27x.c index 7e945836e1..bc2e80f696 100644 --- a/arch/arm/mach-pxa/pxa27x.c +++ b/arch/arm/mach-pxa/pxa27x.c @@ -157,12 +157,13 @@ static struct clk pxa27x_clks[] = { INIT_CKEN("SSPCLK", SSP1, 13000000, 0, &pxa27x_device_ssp1.dev), INIT_CKEN("SSPCLK", SSP2, 13000000, 0, &pxa27x_device_ssp2.dev), INIT_CKEN("SSPCLK", SSP3, 13000000, 0, &pxa27x_device_ssp3.dev), + INIT_CKEN("PWMCLK", PWM0, 13000000, 0, &pxa27x_device_pwm0.dev), + INIT_CKEN("PWMCLK", PWM1, 13000000, 0, &pxa27x_device_pwm1.dev), INIT_CKEN("AC97CLK", AC97, 24576000, 0, NULL), INIT_CKEN("AC97CONFCLK", AC97CONF, 24576000, 0, NULL), /* - INIT_CKEN("PWMCLK", PWM0, 13000000, 0, NULL), INIT_CKEN("MSLCLK", MSL, 48000000, 0, NULL), INIT_CKEN("USIMCLK", USIM, 48000000, 0, NULL), INIT_CKEN("MSTKCLK", MEMSTK, 19500000, 0, NULL), @@ -363,6 +364,8 @@ static struct platform_device *devices[] __initdata = { &pxa27x_device_ssp1, &pxa27x_device_ssp2, &pxa27x_device_ssp3, + &pxa27x_device_pwm0, + &pxa27x_device_pwm1, }; static struct sys_device pxa27x_sysdev[] = { diff --git a/arch/arm/mach-pxa/pxa3xx.c b/arch/arm/mach-pxa/pxa3xx.c index 644550bfa3..0f717df1fd 100644 --- a/arch/arm/mach-pxa/pxa3xx.c +++ b/arch/arm/mach-pxa/pxa3xx.c @@ -239,6 +239,8 @@ static struct clk pxa3xx_clks[] = { PXA3xx_CKEN("SSPCLK", SSP2, 13000000, 0, &pxa27x_device_ssp2.dev), PXA3xx_CKEN("SSPCLK", SSP3, 13000000, 0, &pxa27x_device_ssp3.dev), PXA3xx_CKEN("SSPCLK", SSP4, 13000000, 0, &pxa3xx_device_ssp4.dev), + PXA3xx_CKEN("PWMCLK", PWM0, 13000000, 0, &pxa27x_device_pwm0.dev), + PXA3xx_CKEN("PWMCLK", PWM1, 13000000, 0, &pxa27x_device_pwm1.dev), PXA3xx_CKEN("MMCCLK", MMC1, 19500000, 0, &pxa_device_mci.dev), PXA3xx_CKEN("MMCCLK", MMC2, 19500000, 0, &pxa3xx_device_mci2.dev), @@ -530,6 +532,8 @@ static struct platform_device *devices[] __initdata = { &pxa27x_device_ssp2, &pxa27x_device_ssp3, &pxa3xx_device_ssp4, + &pxa27x_device_pwm0, + &pxa27x_device_pwm1, }; static struct sys_device pxa3xx_sysdev[] = {