ENGR00153921 Add MC34708 PWM support

This driver privides dedicated APIs similar to ones provided
by Linux PWM framework.

MC34708 PWM supports period of time from 16000 ns to 1024000 ns,
with the step of 16000 ns. The duty cycle is multiple of 1/32.

Signed-off-by: Robby Cai <R63905@freescale.com>

5 files changed, 280 insertions, 0 deletions

diff --git a/drivers/mxc/pmic/core/pmic_core_i2c.c b/drivers/mxc/pmic/core/pmic_core_i2c.c
index c839cb991811..77530c421e2b 100644
--- a/drivers/mxc/pmic/core/pmic_core_i2c.c
+++ b/drivers/mxc/pmic/core/pmic_core_i2c.c
@@ -94,6 +94,14 @@ static struct platform_device bleds_ldm = {
 	.name = "pmic_leds",
 	.id = 'b',
 };
+static struct platform_device pwm1_ldm = {
+	.name = "pmic_pwm",
+	.id = 0,
+};
+static struct platform_device pwm2_ldm = {
+	.name = "pmic_pwm",
+	.id = 1,
+};
 
 enum pmic_id {
 	PMIC_ID_MC13892,
@@ -175,6 +183,8 @@ static void pmic_pdev_register(struct device *dev)
 	platform_device_register(&rleds_ldm);
 	platform_device_register(&gleds_ldm);
 	platform_device_register(&bleds_ldm);
+	platform_device_register(&pwm1_ldm);
+	platform_device_register(&pwm2_ldm);
 }
 
 /*!
@@ -188,6 +198,8 @@ static void pmic_pdev_unregister(void)
 	platform_device_unregister(&rtc_ldm);
 	platform_device_unregister(&power_ldm);
 	platform_device_unregister(&light_ldm);
+	platform_device_unregister(&pwm1_ldm);
+	platform_device_unregister(&pwm2_ldm);
 }
 
 static int __devinit is_chip_onboard(struct i2c_client *client)
@@ -285,6 +297,8 @@ static int __devinit pmic_probe(struct i2c_client *client,
 	battery_ldm.name = get_client_device_name(name, "%s_battery");
 	light_ldm.name = get_client_device_name(name, "%s_light");
 	rtc_ldm.name = get_client_device_name(name, "%s_rtc");
+	pwm1_ldm.name = get_client_device_name(name, "%s_pwm");
+	pwm2_ldm.name = get_client_device_name(name, "%s_pwm");
 
 	i2c_set_clientdata(client,
 		pmic_internal[pmic_index].pmic_alloc_data(&client->dev));
diff --git a/drivers/mxc/pmic/core/pmic_core_spi.c b/drivers/mxc/pmic/core/pmic_core_spi.c
index 70212aec4be5..fcb2c0ad3d95 100644
--- a/drivers/mxc/pmic/core/pmic_core_spi.c
+++ b/drivers/mxc/pmic/core/pmic_core_spi.c
@@ -87,6 +87,14 @@ static struct platform_device bleds_ldm = {
 	.name = "pmic_leds",
 	.id = 'b',
 };
+static struct platform_device pwm1_ldm = {
+	.name = "pmic_pwm",
+	.id = 0,
+};
+static struct platform_device pwm2_ldm = {
+	.name = "pmic_pwm",
+	.id = 1,
+};
 
 enum pmic_id {
 	PMIC_ID_MC13892,
@@ -159,6 +167,8 @@ static void pmic_pdev_register(void)
 	platform_device_register(&rleds_ldm);
 	platform_device_register(&gleds_ldm);
 	platform_device_register(&bleds_ldm);
+	platform_device_register(&pwm1_ldm);
+	platform_device_register(&pwm2_ldm);
 }
 
 /*!
@@ -172,6 +182,8 @@ static void pmic_pdev_unregister(void)
 	platform_device_unregister(&rtc_ldm);
 	platform_device_unregister(&power_ldm);
 	platform_device_unregister(&light_ldm);
+	platform_device_unregister(&pwm1_ldm);
+	platform_device_unregister(&pwm2_ldm);
 }
 
 /*!
@@ -232,6 +244,8 @@ static int __devinit pmic_probe(struct spi_device *spi)
 	battery_ldm.name = get_client_device_name(name, "%s_battery");
 	light_ldm.name = get_client_device_name(name, "%s_light");
 	rtc_ldm.name = get_client_device_name(name, "%s_rtc");
+	pwm1_ldm.name = get_client_device_name(name, "%s_pwm");
+	pwm2_ldm.name = get_client_device_name(name, "%s_pwm");
 
 	/* Initialize the PMIC event handling */
 	pmic_event_list_init();
diff --git a/drivers/mxc/pmic/mc34708/Kconfig b/drivers/mxc/pmic/mc34708/Kconfig
index 612ebdb0deb7..a1633cfe9200 100644
--- a/drivers/mxc/pmic/mc34708/Kconfig
+++ b/drivers/mxc/pmic/mc34708/Kconfig
@@ -25,3 +25,11 @@ config MXC_MC34708_BATTERY
 	This is the MC34708 battery module driver. This module provides kernel API
 	for battery control part of MC34708.
 	If you want MC34708 battery support, you should say Y here
+
+config MXC_MC34708_PWM
+	tristate "MC34708 PWM API support"
+	depends on MXC_PMIC_MC34708
+	---help---
+	This is the MC34708 PWM module driver. This module provides kernel API
+	for PWM control part of MC34708.
+	If you want MC34708 PWM support, you should say Y here
diff --git a/drivers/mxc/pmic/mc34708/Makefile b/drivers/mxc/pmic/mc34708/Makefile
index 6e1c907e8f35..9e6a91dbb23c 100644
--- a/drivers/mxc/pmic/mc34708/Makefile
+++ b/drivers/mxc/pmic/mc34708/Makefile
@@ -6,5 +6,6 @@ obj-$(CONFIG_MXC_MC34708_ADC) += mc34708_adc.o
 #obj-$(CONFIG_MXC_MC34708_RTC) += mc34708_rtc.o
 obj-$(CONFIG_MXC_MC34708_LIGHT) += mc34708_light.o
 obj-$(CONFIG_MXC_MC34708_BATTERY) += mc34708_battery.o
+obj-$(CONFIG_MXC_MC34708_PWM) += mc34708_pwm.o
 #obj-$(CONFIG_MXC_MC34708_CONNECTIVITY) += mc34708_convity.o
 #obj-$(CONFIG_MXC_MC34708_POWER) += mc34708_power.o
diff --git a/drivers/mxc/pmic/mc34708/mc34708_pwm.c b/drivers/mxc/pmic/mc34708/mc34708_pwm.c
new file mode 100644
index 000000000000..00b0e28dbceb
--- /dev/null
+++ b/drivers/mxc/pmic/mc34708/mc34708_pwm.c
@@ -0,0 +1,243 @@
+/*
+ * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ */
+
+/*
+ * based on arch/arm/plat-mxc/pwm.c
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/pmic_status.h>
+#include <linux/pmic_external.h>
+#include <linux/mfd/mc34708/mc34708.h>
+#include <linux/mfd/mc34708/mc34708_pwm.h>
+
+#define PWM1DUTY_SHIFT		0
+#define PWM1CLKDIV_SHIFT	6
+#define PWM2DUTY_SHIFT		12
+
+#define BASE_CLK_FREQ		(2000000 / 32) /* base clk: 2MHz/32 */
+#define MAX_CLK_DIV		64
+#define PERIOD_NS_LOW_LIMIT	(1000000000 / BASE_CLK_FREQ)
+#define PERIOD_NS_HIGH_LIMIT	(PERIOD_NS_LOW_LIMIT * MAX_CLK_DIV)
+
+static DEFINE_MUTEX(pwm_lock);
+static LIST_HEAD(pwm_list);
+
+struct pwm_device {
+	struct list_head	node;
+	struct platform_device *pdev;
+	const char	*label;
+
+	unsigned int	use_count;
+	unsigned int	pwm_id;
+	unsigned int	duty_cycles;
+};
+
+int mc34708_pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
+{
+	unsigned long long c;
+	unsigned long period_cycles;
+	u32 offset;
+
+	if (pwm == NULL || period_ns == 0 || duty_ns > period_ns)
+		return -EINVAL;
+
+	if (period_ns < PERIOD_NS_LOW_LIMIT) {
+		dev_warn(&pwm->pdev->dev,
+			"Period time LESSER than the low limit,"
+			" forced to %d ns.\n",
+			PERIOD_NS_LOW_LIMIT);
+
+		period_cycles = 1;
+		period_ns = PERIOD_NS_LOW_LIMIT;
+	} else if (period_ns > PERIOD_NS_HIGH_LIMIT) {
+		dev_warn(&pwm->pdev->dev,
+			"Period time BEYOND the high limit, forced to %d ns.\n",
+			PERIOD_NS_HIGH_LIMIT);
+
+		period_cycles = MAX_CLK_DIV;
+		period_ns = PERIOD_NS_HIGH_LIMIT;
+		if (duty_ns > period_ns)
+			duty_ns = period_ns;
+	} else {
+		c = period_ns;
+		do_div(c, 1000);
+		c = c * BASE_CLK_FREQ;
+		do_div(c, 1000000);
+		period_cycles = c;
+	}
+
+	offset = pwm->pwm_id * PWM2DUTY_SHIFT + PWM1CLKDIV_SHIFT;
+	pmic_write_reg(MC34708_REG_PWM_CTL, (period_cycles - 1) << offset,
+			0x3F << offset);
+
+	c = (unsigned long long)duty_ns * 32;
+	do_div(c, period_ns);
+	pwm->duty_cycles = c;
+
+	/* The following is for debug purpose */
+	period_ns = PERIOD_NS_LOW_LIMIT * period_cycles;
+	duty_ns = (pwm->duty_cycles == 0) ?
+			0 : (period_ns * pwm->duty_cycles / 32);
+	dev_dbg(&pwm->pdev->dev, "set duty_ns %d, period_ns %d\n",
+		duty_ns, period_ns);
+
+	return 0;
+}
+EXPORT_SYMBOL(mc34708_pwm_config);
+
+int mc34708_pwm_enable(struct pwm_device *pwm)
+{
+	int rc = 0;
+	u32 offset;
+
+	/* No dedicated {EN|DIS}ABLE bit, it's controlled by duty cycle */
+	offset = pwm->pwm_id * PWM2DUTY_SHIFT;
+	rc = pmic_write_reg(MC34708_REG_PWM_CTL, pwm->duty_cycles << offset,
+			0x3F << offset);
+	dev_dbg(&pwm->pdev->dev, "%s: duty_cycles %d\n",
+			__func__, pwm->duty_cycles);
+
+	return rc;
+}
+EXPORT_SYMBOL(mc34708_pwm_enable);
+
+void mc34708_pwm_disable(struct pwm_device *pwm)
+{
+	u32 offset;
+
+	offset = pwm->pwm_id * PWM2DUTY_SHIFT;
+	pmic_write_reg(MC34708_REG_PWM_CTL, 0, 0x3F << offset);
+
+}
+EXPORT_SYMBOL(mc34708_pwm_disable);
+
+struct pwm_device *mc34708_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(mc34708_pwm_request);
+
+void mc34708_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(mc34708_pwm_free);
+
+static int __devinit mc34708_pwm_probe(struct platform_device *pdev)
+{
+	struct pwm_device *pwm;
+
+	if (pdev->id != 0 && pdev->id != 1) {
+		dev_err(&pdev->dev, "pdev->id (pwm_id) should be 0 or 1,"
+			"instead of %d\n", pdev->id);
+		return -EINVAL;
+	}
+
+	pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL);
+	if (pwm == NULL) {
+		dev_err(&pdev->dev, "failed to allocate memory\n");
+		return -ENOMEM;
+	}
+
+	pwm->use_count = 0;
+	pwm->pwm_id = pdev->id;
+	pwm->pdev = pdev;
+
+	mutex_lock(&pwm_lock);
+	list_add_tail(&pwm->node, &pwm_list);
+	mutex_unlock(&pwm_lock);
+
+	platform_set_drvdata(pdev, pwm);
+
+	return 0;
+}
+
+static int __devexit mc34708_pwm_remove(struct platform_device *pdev)
+{
+	struct pwm_device *pwm;
+
+	pwm = platform_get_drvdata(pdev);
+	if (pwm == NULL)
+		return -ENODEV;
+
+	mutex_lock(&pwm_lock);
+	list_del(&pwm->node);
+	mutex_unlock(&pwm_lock);
+
+	kfree(pwm);
+	return 0;
+}
+
+static struct platform_driver mc34708_pwm_driver = {
+	.driver		= {
+		.name	= "mc34708_pwm",
+	},
+	.probe		= mc34708_pwm_probe,
+	.remove		= __devexit_p(mc34708_pwm_remove),
+};
+
+static int __init mc34708_pwm_init(void)
+{
+	return platform_driver_register(&mc34708_pwm_driver);
+}
+arch_initcall(mc34708_pwm_init);
+
+static void __exit mc34708_pwm_exit(void)
+{
+	platform_driver_unregister(&mc34708_pwm_driver);
+}
+module_exit(mc34708_pwm_exit);
+
+MODULE_DESCRIPTION("MC34708 PWM driver");
+MODULE_AUTHOR("Freescale Semiconductor, Inc.");
+MODULE_LICENSE("GPL");