[PATCH] ARM: i.MX23/28: Add pwm driver
Sascha Hauer
s.hauer at pengutronix.de
Thu Jan 27 06:48:28 EST 2011
Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
arch/arm/mach-mxs/Kconfig | 2 +
arch/arm/mach-mxs/Makefile | 2 +
arch/arm/mach-mxs/clock-mx23.c | 6 +-
arch/arm/mach-mxs/clock-mx28.c | 9 +-
arch/arm/mach-mxs/devices-mx23.h | 3 +
arch/arm/mach-mxs/devices-mx28.h | 3 +
arch/arm/mach-mxs/devices/Kconfig | 4 +
arch/arm/mach-mxs/devices/Makefile | 1 +
arch/arm/mach-mxs/devices/platform-pwm.c | 25 ++
arch/arm/mach-mxs/include/mach/devices-common.h | 5 +
arch/arm/mach-mxs/pwm.c | 318 +++++++++++++++++++++++
11 files changed, 376 insertions(+), 2 deletions(-)
create mode 100644 arch/arm/mach-mxs/devices/platform-pwm.c
create mode 100644 arch/arm/mach-mxs/pwm.c
diff --git a/arch/arm/mach-mxs/Kconfig b/arch/arm/mach-mxs/Kconfig
index cd2fbdf..99813e0 100644
--- a/arch/arm/mach-mxs/Kconfig
+++ b/arch/arm/mach-mxs/Kconfig
@@ -8,10 +8,12 @@ config MXS_OCOTP
config SOC_IMX23
bool
select CPU_ARM926T
+ select HAVE_PWM
config SOC_IMX28
bool
select CPU_ARM926T
+ select HAVE_PWM
comment "MXS platforms:"
diff --git a/arch/arm/mach-mxs/Makefile b/arch/arm/mach-mxs/Makefile
index 6b26f02..5c7ce1f 100644
--- a/arch/arm/mach-mxs/Makefile
+++ b/arch/arm/mach-mxs/Makefile
@@ -7,6 +7,8 @@ obj-$(CONFIG_PM) += pm.o
obj-$(CONFIG_SOC_IMX23) += clock-mx23.o mm-mx23.o
obj-$(CONFIG_SOC_IMX28) += clock-mx28.o mm-mx28.o
+obj-$(CONFIG_MXS_HAVE_PLATFORM_PWM) += pwm.o
+
obj-$(CONFIG_MACH_MX23EVK) += mach-mx23evk.o
obj-$(CONFIG_MACH_MX28EVK) += mach-mx28evk.o
diff --git a/arch/arm/mach-mxs/clock-mx23.c b/arch/arm/mach-mxs/clock-mx23.c
index b1a362e..017d4a3 100644
--- a/arch/arm/mach-mxs/clock-mx23.c
+++ b/arch/arm/mach-mxs/clock-mx23.c
@@ -446,7 +446,11 @@ static struct clk_lookup lookups[] = {
_REGISTER_CLOCK(NULL, "hclk", hbus_clk)
_REGISTER_CLOCK(NULL, "usb", usb_clk)
_REGISTER_CLOCK(NULL, "audio", audio_clk)
- _REGISTER_CLOCK(NULL, "pwm", pwm_clk)
+ _REGISTER_CLOCK("mxs-pwm.0", NULL, pwm_clk)
+ _REGISTER_CLOCK("mxs-pwm.1", NULL, pwm_clk)
+ _REGISTER_CLOCK("mxs-pwm.2", NULL, pwm_clk)
+ _REGISTER_CLOCK("mxs-pwm.3", NULL, pwm_clk)
+ _REGISTER_CLOCK("mxs-pwm.4", NULL, pwm_clk)
};
static int clk_misc_init(void)
diff --git a/arch/arm/mach-mxs/clock-mx28.c b/arch/arm/mach-mxs/clock-mx28.c
index 2f1a990..4b48b0a 100644
--- a/arch/arm/mach-mxs/clock-mx28.c
+++ b/arch/arm/mach-mxs/clock-mx28.c
@@ -623,7 +623,14 @@ static struct clk_lookup lookups[] = {
_REGISTER_CLOCK(NULL, "can1", can1_clk)
_REGISTER_CLOCK(NULL, "usb0", usb0_clk)
_REGISTER_CLOCK(NULL, "usb1", usb1_clk)
- _REGISTER_CLOCK(NULL, "pwm", pwm_clk)
+ _REGISTER_CLOCK("mxs-pwm.0", NULL, pwm_clk)
+ _REGISTER_CLOCK("mxs-pwm.1", NULL, pwm_clk)
+ _REGISTER_CLOCK("mxs-pwm.2", NULL, pwm_clk)
+ _REGISTER_CLOCK("mxs-pwm.3", NULL, pwm_clk)
+ _REGISTER_CLOCK("mxs-pwm.4", NULL, pwm_clk)
+ _REGISTER_CLOCK("mxs-pwm.5", NULL, pwm_clk)
+ _REGISTER_CLOCK("mxs-pwm.6", NULL, pwm_clk)
+ _REGISTER_CLOCK("mxs-pwm.7", NULL, pwm_clk)
_REGISTER_CLOCK(NULL, "lradc", lradc_clk)
_REGISTER_CLOCK(NULL, "spdif", spdif_clk)
};
diff --git a/arch/arm/mach-mxs/devices-mx23.h b/arch/arm/mach-mxs/devices-mx23.h
index 1256788..fb9def8 100644
--- a/arch/arm/mach-mxs/devices-mx23.h
+++ b/arch/arm/mach-mxs/devices-mx23.h
@@ -14,3 +14,6 @@
extern const struct amba_device mx23_duart_device __initconst;
#define mx23_add_duart() \
mxs_add_duart(&mx23_duart_device)
+
+#define mx23_add_pwm(id) mxs_add_pwm(MX23_PWM_BASE_ADDR, pdata)
+
diff --git a/arch/arm/mach-mxs/devices-mx28.h b/arch/arm/mach-mxs/devices-mx28.h
index 1ab7bf0..6927250 100644
--- a/arch/arm/mach-mxs/devices-mx28.h
+++ b/arch/arm/mach-mxs/devices-mx28.h
@@ -26,3 +26,6 @@ extern const struct mxs_auart_data mx28_auart_data[] __initconst;
extern const struct mxs_fec_data mx28_fec_data[] __initconst;
#define mx28_add_fec(id, pdata) \
mxs_add_fec(&mx28_fec_data[id], pdata)
+
+#define mx28_add_pwm(id) mxs_add_pwm(MX28_PWM_BASE_ADDR, id)
+
diff --git a/arch/arm/mach-mxs/devices/Kconfig b/arch/arm/mach-mxs/devices/Kconfig
index 3001b75..f8599e5 100644
--- a/arch/arm/mach-mxs/devices/Kconfig
+++ b/arch/arm/mach-mxs/devices/Kconfig
@@ -7,3 +7,7 @@ config MXS_HAVE_PLATFORM_AUART
config MXS_HAVE_PLATFORM_FEC
bool
+
+config MXS_HAVE_PLATFORM_PWM
+ bool
+
diff --git a/arch/arm/mach-mxs/devices/Makefile b/arch/arm/mach-mxs/devices/Makefile
index c814d05..cdb026e 100644
--- a/arch/arm/mach-mxs/devices/Makefile
+++ b/arch/arm/mach-mxs/devices/Makefile
@@ -1,3 +1,4 @@
obj-$(CONFIG_MXS_HAVE_AMBA_DUART) += amba-duart.o
obj-$(CONFIG_MXS_HAVE_PLATFORM_AUART) += platform-auart.o
obj-$(CONFIG_MXS_HAVE_PLATFORM_FEC) += platform-fec.o
+obj-$(CONFIG_MXS_HAVE_PLATFORM_PWM) += platform-pwm.o
diff --git a/arch/arm/mach-mxs/devices/platform-pwm.c b/arch/arm/mach-mxs/devices/platform-pwm.c
new file mode 100644
index 0000000..2f1f549
--- /dev/null
+++ b/arch/arm/mach-mxs/devices/platform-pwm.c
@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2010 Pengutronix
+ * Sascha Hauer <s.hauer at pengutronix.de>
+ *
+ * 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 <asm/sizes.h>
+#include <mach/mx23.h>
+#include <mach/mx28.h>
+#include <mach/devices-common.h>
+
+struct platform_device *__init mxs_add_pwm(resource_size_t iobase, int id)
+{
+ struct resource res = {
+ .flags = IORESOURCE_MEM,
+ };
+
+ res.start = iobase + 0x10 + 0x20 * id;
+ res.end = res.start + 0x1f;
+
+ return mxs_add_platform_device("mxs-pwm", id, &res, 1, NULL, 0);
+}
+
diff --git a/arch/arm/mach-mxs/include/mach/devices-common.h b/arch/arm/mach-mxs/include/mach/devices-common.h
index bed4002..82d5311 100644
--- a/arch/arm/mach-mxs/include/mach/devices-common.h
+++ b/arch/arm/mach-mxs/include/mach/devices-common.h
@@ -51,3 +51,8 @@ struct mxs_fec_data {
struct platform_device *__init mxs_add_fec(
const struct mxs_fec_data *data,
const struct fec_platform_data *pdata);
+
+/* pwm */
+struct platform_device *__init mxs_add_pwm(
+ resource_size_t iobase, int id);
+
diff --git a/arch/arm/mach-mxs/pwm.c b/arch/arm/mach-mxs/pwm.c
new file mode 100644
index 0000000..f2c83a6
--- /dev/null
+++ b/arch/arm/mach-mxs/pwm.c
@@ -0,0 +1,318 @@
+/*
+ * Copyright (C) 2010 Pengutronix
+ * Sascha Hauer <s.hauer at pengutronix.de>
+ *
+ * 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 at marvell.com>
+ */
+
+#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/delay.h>
+#include <linux/io.h>
+#include <linux/pwm.h>
+#include <mach/hardware.h>
+#include <mach/mxs.h>
+#include <mach/mx23.h>
+#include <mach/mx28.h>
+#include <asm/div64.h>
+
+struct pwm_device {
+ struct list_head node;
+ struct device *dev;
+
+ const char *label;
+ struct clk *clk;
+
+ int enabled;
+ void __iomem *mmio_base;
+
+ unsigned int use_count;
+ unsigned int pwm_id;
+
+ u32 val_active;
+ u32 val_period;
+ int period_us;
+};
+
+/* common register space */
+static void __iomem *pwm_base_common;
+#define REG_PWM_CTRL 0x0
+#define PWM_SFTRST (1 << 31)
+#define PWM_CLKGATE (1 << 30)
+#define PWM_ENABLE(p) (1 << (p))
+
+/* per pwm register space */
+#define REG_ACTIVE 0x0
+#define REG_PERIOD 0x10
+
+#define PERIOD_PERIOD(p) ((p) & 0xffff)
+#define PERIOD_ACTIVE_HIGH (3 << 16)
+#define PERIOD_INACTIVE_LOW (2 << 18)
+#define PERIOD_CDIV(div) (((div) & 0x7) << 20)
+
+static void pwm_update(struct pwm_device *pwm)
+{
+ writel(pwm->val_active, pwm->mmio_base + REG_ACTIVE);
+ writel(pwm->val_period, pwm->mmio_base + REG_PERIOD);
+}
+
+int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
+{
+ int div = 0;
+ unsigned long rate;
+ unsigned long long c;
+ unsigned long period_cycles, duty_cycles;
+
+ if (pwm == NULL || period_ns == 0 || duty_ns > period_ns)
+ return -EINVAL;
+
+ rate = clk_get_rate(pwm->clk);
+
+ dev_dbg(pwm->dev, "config: duty_ns: %d, period_ns: %d (clkrate %ld)\n",
+ duty_ns, period_ns, rate);
+
+ while (1) {
+ c = rate / (1 << div);
+ c = c * period_ns;
+ do_div(c, 1000000000);
+ if (c < 0x10000)
+ break;
+ div++;
+
+ if (div > 8)
+ return -EINVAL;
+ }
+
+ period_cycles = c;
+ duty_cycles = period_cycles * duty_ns / period_ns;
+
+ dev_dbg(pwm->dev, "config period_cycles: %ld duty_cycles: %ld\n",
+ period_cycles, duty_cycles);
+
+ pwm->val_active = period_cycles << 16 | duty_cycles;
+ pwm->val_period = PERIOD_PERIOD(period_cycles) | PERIOD_ACTIVE_HIGH |
+ PERIOD_INACTIVE_LOW | PERIOD_CDIV(div);
+ pwm->period_us = period_ns / 1000;
+
+ pwm_update(pwm);
+
+ return 0;
+}
+EXPORT_SYMBOL(pwm_config);
+
+static void __pwm_enable(struct pwm_device *pwm, int enable)
+{
+ if (enable)
+ __mxs_setl(PWM_ENABLE(pwm->pwm_id), pwm_base_common + REG_PWM_CTRL);
+ else
+ __mxs_clrl(PWM_ENABLE(pwm->pwm_id), pwm_base_common + REG_PWM_CTRL);
+}
+
+int pwm_enable(struct pwm_device *pwm)
+{
+ int rc = 0;
+
+ dev_dbg(pwm->dev, "enable\n");
+
+ if (!pwm->enabled) {
+ rc = clk_enable(pwm->clk);
+ if (!rc) {
+ pwm->enabled = 1;
+ __pwm_enable(pwm, 1);
+ pwm_update(pwm);
+ }
+ }
+ return rc;
+}
+EXPORT_SYMBOL(pwm_enable);
+
+void pwm_disable(struct pwm_device *pwm)
+{
+ dev_dbg(pwm->dev, "disable\n");
+
+ if (pwm->enabled) {
+ /*
+ * We need a little delay here, it takes one period for
+ * the last pwm_config call to take effect. If we disable
+ * the pwm too early it just freezes the current output
+ * state.
+ */
+ usleep_range(pwm->period_us, pwm->period_us * 2);
+ __pwm_enable(pwm, 0);
+ clk_disable(pwm->clk);
+ pwm->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 mxs_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, NULL);
+
+ if (IS_ERR(pwm->clk)) {
+ ret = PTR_ERR(pwm->clk);
+ goto err_free;
+ }
+
+ pwm->enabled = 0;
+
+ pwm->use_count = 0;
+ pwm->pwm_id = pdev->id;
+ pwm->dev = &pdev->dev;
+
+ 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 mxs_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 mxs_pwm_driver = {
+ .driver = {
+ .name = "mxs-pwm",
+ },
+ .probe = mxs_pwm_probe,
+ .remove = __devexit_p(mxs_pwm_remove),
+};
+
+static int __init mxs_pwm_init(void)
+{
+ if (cpu_is_mx28())
+ pwm_base_common = MX28_IO_ADDRESS(MX28_PWM_BASE_ADDR);
+ else
+ pwm_base_common = MX23_IO_ADDRESS(MX23_PWM_BASE_ADDR);
+
+ __mxs_clrl(PWM_SFTRST | PWM_CLKGATE, pwm_base_common + REG_PWM_CTRL);
+
+ return platform_driver_register(&mxs_pwm_driver);
+}
+arch_initcall(mxs_pwm_init);
+
+static void __exit mxs_pwm_exit(void)
+{
+ platform_driver_unregister(&mxs_pwm_driver);
+}
+module_exit(mxs_pwm_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Sascha Hauer <s.hauer at pengutronix.de>");
--
1.7.2.3
--
Pengutronix e.K. | |
Industrial Linux Solutions | http://www.pengutronix.de/ |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
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