misc: Add ab8500 pwm driver

This patch adds a Pulse Width Modulation driver for Analog Baseband Chip AB8500. Signed-off-by: Arun Murthy <arun.murthy@stericsson.com> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Acked-by: Mike Rapoport <mike@compulab.co.il> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

misc: Add ab8500 pwm driver
This patch adds a Pulse Width Modulation driver for Analog Baseband Chip AB8500. Signed-off-by: Arun Murthy <arun.murthy@stericsson.com> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Acked-by: Mike Rapoport <mike@compulab.co.il> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Arun Murthy · Samuel Ortiz
1 parent 47c1697508
Showing 4 changed files with 190 additions and 1 deletions Side-by-side Diff
drivers/mfd/ab8500-core.c
drivers/misc/Kconfig
drivers/misc/Makefile
drivers/misc/ab8500-pwm.c
@@ -404,10 +404,21 @@
 		.num_resources = ARRAY_SIZE(ab8500_rtc_resources),
 		.resources = ab8500_rtc_resources,
 	},
+	{
+		.name = "ab8500-pwm",
+		.id = 1,
+	},
+	{
+		.name = "ab8500-pwm",
+		.id = 2,
+	},
+	{
+		.name = "ab8500-pwm",
+		.id = 3,
+	},
 	{ .name = "ab8500-charger", },
 	{ .name = "ab8500-audio", },
 	{ .name = "ab8500-usb", },
-	{ .name = "ab8500-pwm", },
 	{ .name = "ab8500-regulator", },
 	{
 		.name = "ab8500-poweron-key",
@@ -62,6 +62,15 @@
 	  purposes including software controlled power-efficient backlights
 	  on LCD displays, motor control, and waveform generation.
  
+config AB8500_PWM
+	bool "AB8500 PWM support"
+	depends on AB8500_CORE
+	select HAVE_PWM
+	help
+	  This driver exports functions to enable/disble/config/free Pulse
+	  Width Modulation in the Analog Baseband Chip AB8500.
+	  It is used by led and backlight driver to control the intensity.
+
 config ATMEL_TCLIB
 	bool "Atmel AT32/AT91 Timer/Counter Library"
 	depends on (AVR32 || ARCH_AT91)
@@ -41,4 +41,5 @@
 obj-$(CONFIG_ARM_CHARLCD)	+= arm-charlcd.o
 obj-$(CONFIG_PCH_PHUB)		+= pch_phub.o
 obj-y				+= ti-st/
+obj-$(CONFIG_AB8500_PWM)	+= ab8500-pwm.o
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * Author: Arun R Murthy <arun.murthy@stericsson.com>
+ * License terms: GNU General Public License (GPL) version 2
+ */
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/pwm.h>
+#include <linux/mfd/ab8500.h>
+#include <linux/mfd/abx500.h>
+
+/*
+ * PWM Out generators
+ * Bank: 0x10
+ */
+#define AB8500_PWM_OUT_CTRL1_REG	0x60
+#define AB8500_PWM_OUT_CTRL2_REG	0x61
+#define AB8500_PWM_OUT_CTRL7_REG	0x66
+
+/* backlight driver constants */
+#define ENABLE_PWM			1
+#define DISABLE_PWM			0
+
+struct pwm_device {
+	struct device *dev;
+	struct list_head node;
+	const char *label;
+	unsigned int pwm_id;
+};
+
+static LIST_HEAD(pwm_list);
+
+int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
+{
+	int ret = 0;
+	unsigned int higher_val, lower_val;
+	u8 reg;
+
+	/*
+	 * get the first 8 bits that are be written to
+	 * AB8500_PWM_OUT_CTRL1_REG[0:7]
+	 */
+	lower_val = duty_ns & 0x00FF;
+	/*
+	 * get bits [9:10] that are to be written to
+	 * AB8500_PWM_OUT_CTRL2_REG[0:1]
+	 */
+	higher_val = ((duty_ns & 0x0300) >> 8);
+
+	reg = AB8500_PWM_OUT_CTRL1_REG + ((pwm->pwm_id - 1) * 2);
+
+	ret = abx500_set_register_interruptible(pwm->dev, AB8500_MISC,
+			reg, (u8)lower_val);
+	if (ret < 0)
+		return ret;
+	ret = abx500_set_register_interruptible(pwm->dev, AB8500_MISC,
+			(reg + 1), (u8)higher_val);
+
+	return ret;
+}
+EXPORT_SYMBOL(pwm_config);
+
+int pwm_enable(struct pwm_device *pwm)
+{
+	int ret;
+
+	ret = abx500_mask_and_set_register_interruptible(pwm->dev,
+				AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
+				1 << (pwm->pwm_id-1), ENABLE_PWM);
+	if (ret < 0)
+		dev_err(pwm->dev, "%s: Failed to disable PWM, Error %d\n",
+							pwm->label, ret);
+	return ret;
+}
+EXPORT_SYMBOL(pwm_enable);
+
+void pwm_disable(struct pwm_device *pwm)
+{
+	int ret;
+
+	ret = abx500_mask_and_set_register_interruptible(pwm->dev,
+				AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
+				1 << (pwm->pwm_id-1), DISABLE_PWM);
+	if (ret < 0)
+		dev_err(pwm->dev, "%s: Failed to disable PWM, Error %d\n",
+							pwm->label, ret);
+	return;
+}
+EXPORT_SYMBOL(pwm_disable);
+
+struct pwm_device *pwm_request(int pwm_id, const char *label)
+{
+	struct pwm_device *pwm;
+
+	list_for_each_entry(pwm, &pwm_list, node) {
+		if (pwm->pwm_id == pwm_id) {
+			pwm->label = label;
+			pwm->pwm_id = pwm_id;
+			return pwm;
+		}
+	}
+
+	return ERR_PTR(-ENOENT);
+}
+EXPORT_SYMBOL(pwm_request);
+
+void pwm_free(struct pwm_device *pwm)
+{
+	pwm_disable(pwm);
+}
+EXPORT_SYMBOL(pwm_free);
+
+static int __devinit ab8500_pwm_probe(struct platform_device *pdev)
+{
+	struct pwm_device *pwm;
+	/*
+	 * Nothing to be done in probe, this is required to get the
+	 * device which is required for ab8500 read and write
+	 */
+	pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL);
+	if (pwm == NULL) {
+		dev_err(&pdev->dev, "failed to allocate memory\n");
+		return -ENOMEM;
+	}
+	pwm->dev = &pdev->dev;
+	pwm->pwm_id = pdev->id;
+	list_add_tail(&pwm->node, &pwm_list);
+	platform_set_drvdata(pdev, pwm);
+	dev_dbg(pwm->dev, "pwm probe successful\n");
+	return 0;
+}
+
+static int __devexit ab8500_pwm_remove(struct platform_device *pdev)
+{
+	struct pwm_device *pwm = platform_get_drvdata(pdev);
+	list_del(&pwm->node);
+	dev_dbg(&pdev->dev, "pwm driver removed\n");
+	kfree(pwm);
+	return 0;
+}
+
+static struct platform_driver ab8500_pwm_driver = {
+	.driver = {
+		.name = "ab8500-pwm",
+		.owner = THIS_MODULE,
+	},
+	.probe = ab8500_pwm_probe,
+	.remove = __devexit_p(ab8500_pwm_remove),
+};
+
+static int __init ab8500_pwm_init(void)
+{
+	return platform_driver_register(&ab8500_pwm_driver);
+}
+
+static void __exit ab8500_pwm_exit(void)
+{
+	platform_driver_unregister(&ab8500_pwm_driver);
+}
+
+subsys_initcall(ab8500_pwm_init);
+module_exit(ab8500_pwm_exit);
+MODULE_AUTHOR("Arun MURTHY <arun.murthy@stericsson.com>");
+MODULE_DESCRIPTION("AB8500 Pulse Width Modulation Driver");
+MODULE_ALIAS("AB8500 PWM driver");
+MODULE_LICENSE("GPL v2");
...	...	@@ -404,10 +404,21 @@
404	404	.num_resources = ARRAY_SIZE(ab8500_rtc_resources),
405	405	.resources = ab8500_rtc_resources,
406	406	},
	407	+ {
	408	+ .name = "ab8500-pwm",
	409	+ .id = 1,
	410	+ },
	411	+ {
	412	+ .name = "ab8500-pwm",
	413	+ .id = 2,
	414	+ },
	415	+ {
	416	+ .name = "ab8500-pwm",
	417	+ .id = 3,
	418	+ },
407	419	{ .name = "ab8500-charger", },
408	420	{ .name = "ab8500-audio", },
409	421	{ .name = "ab8500-usb", },
410		- { .name = "ab8500-pwm", },
411	422	{ .name = "ab8500-regulator", },
412	423	{
413	424	.name = "ab8500-poweron-key",
...	...	@@ -62,6 +62,15 @@
62	62	purposes including software controlled power-efficient backlights
63	63	on LCD displays, motor control, and waveform generation.
64	64
	65	+config AB8500_PWM
	66	+ bool "AB8500 PWM support"
	67	+ depends on AB8500_CORE
	68	+ select HAVE_PWM
	69	+ help
	70	+ This driver exports functions to enable/disble/config/free Pulse
	71	+ Width Modulation in the Analog Baseband Chip AB8500.
	72	+ It is used by led and backlight driver to control the intensity.
	73	+
65	74	config ATMEL_TCLIB
66	75	bool "Atmel AT32/AT91 Timer/Counter Library"
67	76	depends on (AVR32 \|\| ARCH_AT91)
...	...	@@ -41,4 +41,5 @@
41	41	obj-$(CONFIG_ARM_CHARLCD) += arm-charlcd.o
42	42	obj-$(CONFIG_PCH_PHUB) += pch_phub.o
43	43	obj-y += ti-st/
	44	+obj-$(CONFIG_AB8500_PWM) += ab8500-pwm.o
	1	+/*
	2	+ * Copyright (C) ST-Ericsson SA 2010
	3	+ *
	4	+ * Author: Arun R Murthy <arun.murthy@stericsson.com>
	5	+ * License terms: GNU General Public License (GPL) version 2
	6	+ */
	7	+#include <linux/err.h>
	8	+#include <linux/platform_device.h>
	9	+#include <linux/slab.h>
	10	+#include <linux/pwm.h>
	11	+#include <linux/mfd/ab8500.h>
	12	+#include <linux/mfd/abx500.h>
	13	+
	14	+/*
	15	+ * PWM Out generators
	16	+ * Bank: 0x10
	17	+ */
	18	+#define AB8500_PWM_OUT_CTRL1_REG 0x60
	19	+#define AB8500_PWM_OUT_CTRL2_REG 0x61
	20	+#define AB8500_PWM_OUT_CTRL7_REG 0x66
	21	+
	22	+/* backlight driver constants */
	23	+#define ENABLE_PWM 1
	24	+#define DISABLE_PWM 0
	25	+
	26	+struct pwm_device {
	27	+ struct device *dev;
	28	+ struct list_head node;
	29	+ const char *label;
	30	+ unsigned int pwm_id;
	31	+};
	32	+
	33	+static LIST_HEAD(pwm_list);
	34	+
	35	+int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
	36	+{
	37	+ int ret = 0;
	38	+ unsigned int higher_val, lower_val;
	39	+ u8 reg;
	40	+
	41	+ /*
	42	+ * get the first 8 bits that are be written to
	43	+ * AB8500_PWM_OUT_CTRL1_REG[0:7]
	44	+ */
	45	+ lower_val = duty_ns & 0x00FF;
	46	+ /*
	47	+ * get bits [9:10] that are to be written to
	48	+ * AB8500_PWM_OUT_CTRL2_REG[0:1]
	49	+ */
	50	+ higher_val = ((duty_ns & 0x0300) >> 8);
	51	+
	52	+ reg = AB8500_PWM_OUT_CTRL1_REG + ((pwm->pwm_id - 1) * 2);
	53	+
	54	+ ret = abx500_set_register_interruptible(pwm->dev, AB8500_MISC,
	55	+ reg, (u8)lower_val);
	56	+ if (ret < 0)
	57	+ return ret;
	58	+ ret = abx500_set_register_interruptible(pwm->dev, AB8500_MISC,
	59	+ (reg + 1), (u8)higher_val);
	60	+
	61	+ return ret;
	62	+}
	63	+EXPORT_SYMBOL(pwm_config);
	64	+
	65	+int pwm_enable(struct pwm_device *pwm)
	66	+{
	67	+ int ret;
	68	+
	69	+ ret = abx500_mask_and_set_register_interruptible(pwm->dev,
	70	+ AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
	71	+ 1 << (pwm->pwm_id-1), ENABLE_PWM);
	72	+ if (ret < 0)
	73	+ dev_err(pwm->dev, "%s: Failed to disable PWM, Error %d\n",
	74	+ pwm->label, ret);
	75	+ return ret;
	76	+}
	77	+EXPORT_SYMBOL(pwm_enable);
	78	+
	79	+void pwm_disable(struct pwm_device *pwm)
	80	+{
	81	+ int ret;
	82	+
	83	+ ret = abx500_mask_and_set_register_interruptible(pwm->dev,
	84	+ AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
	85	+ 1 << (pwm->pwm_id-1), DISABLE_PWM);
	86	+ if (ret < 0)
	87	+ dev_err(pwm->dev, "%s: Failed to disable PWM, Error %d\n",
	88	+ pwm->label, ret);
	89	+ return;
	90	+}
	91	+EXPORT_SYMBOL(pwm_disable);
	92	+
	93	+struct pwm_device pwm_request(int pwm_id, const char label)
	94	+{
	95	+ struct pwm_device *pwm;
	96	+
	97	+ list_for_each_entry(pwm, &pwm_list, node) {
	98	+ if (pwm->pwm_id == pwm_id) {
	99	+ pwm->label = label;
	100	+ pwm->pwm_id = pwm_id;
	101	+ return pwm;
	102	+ }
	103	+ }
	104	+
	105	+ return ERR_PTR(-ENOENT);
	106	+}
	107	+EXPORT_SYMBOL(pwm_request);
	108	+
	109	+void pwm_free(struct pwm_device *pwm)
	110	+{
	111	+ pwm_disable(pwm);
	112	+}
	113	+EXPORT_SYMBOL(pwm_free);
	114	+
	115	+static int __devinit ab8500_pwm_probe(struct platform_device *pdev)
	116	+{
	117	+ struct pwm_device *pwm;
	118	+ /*
	119	+ * Nothing to be done in probe, this is required to get the
	120	+ * device which is required for ab8500 read and write
	121	+ */
	122	+ pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL);
	123	+ if (pwm == NULL) {
	124	+ dev_err(&pdev->dev, "failed to allocate memory\n");
	125	+ return -ENOMEM;
	126	+ }
	127	+ pwm->dev = &pdev->dev;
	128	+ pwm->pwm_id = pdev->id;
	129	+ list_add_tail(&pwm->node, &pwm_list);
	130	+ platform_set_drvdata(pdev, pwm);
	131	+ dev_dbg(pwm->dev, "pwm probe successful\n");
	132	+ return 0;
	133	+}
	134	+
	135	+static int __devexit ab8500_pwm_remove(struct platform_device *pdev)
	136	+{
	137	+ struct pwm_device *pwm = platform_get_drvdata(pdev);
	138	+ list_del(&pwm->node);
	139	+ dev_dbg(&pdev->dev, "pwm driver removed\n");
	140	+ kfree(pwm);
	141	+ return 0;
	142	+}
	143	+
	144	+static struct platform_driver ab8500_pwm_driver = {
	145	+ .driver = {
	146	+ .name = "ab8500-pwm",
	147	+ .owner = THIS_MODULE,
	148	+ },
	149	+ .probe = ab8500_pwm_probe,
	150	+ .remove = __devexit_p(ab8500_pwm_remove),
	151	+};
	152	+
	153	+static int __init ab8500_pwm_init(void)
	154	+{
	155	+ return platform_driver_register(&ab8500_pwm_driver);
	156	+}
	157	+
	158	+static void __exit ab8500_pwm_exit(void)
	159	+{
	160	+ platform_driver_unregister(&ab8500_pwm_driver);
	161	+}
	162	+
	163	+subsys_initcall(ab8500_pwm_init);
	164	+module_exit(ab8500_pwm_exit);
	165	+MODULE_AUTHOR("Arun MURTHY <arun.murthy@stericsson.com>");
	166	+MODULE_DESCRIPTION("AB8500 Pulse Width Modulation Driver");
	167	+MODULE_ALIAS("AB8500 PWM driver");
	168	+MODULE_LICENSE("GPL v2");