Message-ID: <1352381490-30009-3-git-send-email-peter.ujfalusi@ti.com>
Date:	Thu, 8 Nov 2012 14:31:29 +0100
From:	Peter Ujfalusi <peter.ujfalusi@...com>
To:	Thierry Reding <thierry.reding@...onic-design.de>
CC:	Tero Kristo <t-kristo@...com>,
	Grazvydas Ignotas <notasas@...il.com>,
	<linux-kernel@...r.kernel.org>, <linux-omap@...r.kernel.org>
Subject: [PATCH v2 2/3] pwm: New driver to support PWMs on TWL4030/6030 series of PMICs

The driver supports the following PWM outputs:
TWL4030 PWM0 and PWM1
TWL6030 PWM1 and PWM2

On TWL4030 the PWM signals are muxed. Upon requesting the PWM the driver
will select the correct mux so the PWM can be used. When the PWM has been
freed the original configuration going to be restored.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@...com>
---
 drivers/pwm/Kconfig   |  10 ++
 drivers/pwm/Makefile  |   1 +
 drivers/pwm/pwm-twl.c | 322 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 333 insertions(+)
 create mode 100644 drivers/pwm/pwm-twl.c

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index e678005..c577db9 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -142,6 +142,16 @@ config  PWM_TIEHRPWM
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-tiehrpwm.
 
+config PWM_TWL
+	tristate "TWL4030/6030 PWM support"
+	select HAVE_PWM
+	depends on TWL4030_CORE
+	help
+	  Generic PWM framework driver for TWL4030/6030.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pwm-twl.
+
 config PWM_VT8500
 	tristate "vt8500 pwm support"
 	depends on ARCH_VT8500
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index 29cf57e..3324c06 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -11,4 +11,5 @@ obj-$(CONFIG_PWM_SAMSUNG)	+= pwm-samsung.o
 obj-$(CONFIG_PWM_TEGRA)		+= pwm-tegra.o
 obj-$(CONFIG_PWM_TIECAP)	+= pwm-tiecap.o
 obj-$(CONFIG_PWM_TIEHRPWM)	+= pwm-tiehrpwm.o
+obj-$(CONFIG_PWM_TWL)		+= pwm-twl.o
 obj-$(CONFIG_PWM_VT8500)	+= pwm-vt8500.o
diff --git a/drivers/pwm/pwm-twl.c b/drivers/pwm/pwm-twl.c
new file mode 100644
index 0000000..26e57e9
--- /dev/null
+++ b/drivers/pwm/pwm-twl.c
@@ -0,0 +1,322 @@
+/*
+ * Driver for TWL4030/6030 Generic Pulse Width Modulator
+ *
+ * Copyright (C) 2012 Texas Instruments
+ * Author: Peter Ujfalusi <peter.ujfalusi@...com>
+ *
+ * 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.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/i2c/twl.h>
+#include <linux/slab.h>
+
+/*
+ * This driver handles the PWMs of TWL4030 and TWL6030.
+ * The TRM names for the PWMs on TWL4030 are: PWM0, PWM1
+ * TWL6030 also have two PWMs named in the TRM as PWM1, PWM2
+ */
+
+#define TWL_PWM_MAX		0x7f
+
+/* Registers, bits and macro for TWL4030 */
+#define TWL4030_GPBR1_REG	0x0c
+#define TWL4030_PMBR1_REG	0x0d
+
+/* GPBR1 register bits */
+#define TWL4030_PWMXCLK_ENABLE	(1 << 0)
+#define TWL4030_PWMX_ENABLE	(1 << 2)
+#define TWL4030_PWMX_BITS	(TWL4030_PWMX_ENABLE | TWL4030_PWMXCLK_ENABLE)
+#define TWL4030_PWM_TOGGLE(pwm, x)	((x) << (pwm))
+
+/* PMBR1 register bits */
+#define TWL4030_GPIO6_PWM0_MUTE_MASK		(0x03 << 2)
+#define TWL4030_GPIO6_PWM0_MUTE_PWM0		(0x01 << 2)
+#define TWL4030_GPIO7_VIBRASYNC_PWM1_MASK	(0x03 << 4)
+#define TWL4030_GPIO7_VIBRASYNC_PWM1_PWM1	(0x03 << 4)
+
+/* Register, bits and macro for TWL6030 */
+#define TWL6030_TOGGLE3_REG	0x92
+
+#define TWL6030_PWMXR		(1 << 0)
+#define TWL6030_PWMXS		(1 << 1)
+#define TWL6030_PWMXEN		(1 << 2)
+#define TWL6030_PWM_TOGGLE(pwm, x)	((x) << (pwm * 3))
+
+struct twl_pwm_chip {
+	struct pwm_chip chip;
+	u8 twl6030_toggle3;
+	u8 twl4030_pwm_mux;
+};
+
+static int twl_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+			      int duty_ns, int period_ns)
+{
+	int duty_cycle = (duty_ns * TWL_PWM_MAX) / period_ns;
+	u8 on_time;
+	u8 pwm_config[2];
+	int base, ret;
+
+	if (duty_cycle >= TWL_PWM_MAX)
+		on_time = TWL_PWM_MAX;
+	else if (!duty_cycle)
+		on_time = TWL_PWM_MAX - 1;
+	else
+		on_time = TWL_PWM_MAX - duty_cycle;
+
+	base = pwm->hwpwm * 3;
+
+	pwm_config[0] = on_time;
+	pwm_config[1] = TWL_PWM_MAX;
+
+	ret = twl_i2c_write(TWL_MODULE_PWM, pwm_config, base, 2);
+	if (ret < 0)
+		dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
+
+	return ret;
+}
+
+static int twl4030_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	int ret;
+	u8 val;
+
+	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_GPBR1_REG);
+	if (ret < 0) {
+		dev_err(chip->dev, "%s: Failed to read GPBR1\n", pwm->label);
+		return ret;
+	}
+
+	val |= TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMXCLK_ENABLE);
+
+	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
+	if (ret < 0)
+		dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
+
+	val |= TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMX_ENABLE);
+
+	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
+	if (ret < 0)
+		dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
+
+	return ret;
+}
+
+static void twl4030_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	int ret;
+	u8 val;
+
+	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_GPBR1_REG);
+	if (ret < 0) {
+		dev_err(chip->dev, "%s: Failed to read GPBR1\n", pwm->label);
+		return;
+	}
+
+	val &= ~TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMX_ENABLE);
+
+	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
+	if (ret < 0)
+		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
+
+	val &= ~TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMXCLK_ENABLE);
+
+	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG);
+	if (ret < 0)
+		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
+}
+
+static int twl4030_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct twl_pwm_chip *twl = container_of(chip, struct twl_pwm_chip,
+						chip);
+	int ret;
+	u8 val, mask, bits;
+
+	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_PMBR1_REG);
+	if (ret < 0) {
+		dev_err(chip->dev, "%s: Failed to read PMBR1\n", pwm->label);
+		return ret;
+	}
+
+	if (pwm->hwpwm) {
+		/* PWM 1 */
+		mask = TWL4030_GPIO7_VIBRASYNC_PWM1_MASK;
+		bits = TWL4030_GPIO7_VIBRASYNC_PWM1_PWM1;
+	} else {
+		/* PWM 0 */
+		mask = TWL4030_GPIO6_PWM0_MUTE_MASK;
+		bits = TWL4030_GPIO6_PWM0_MUTE_PWM0;
+	}
+
+	/* Save the current MUX configuration for the PWM */
+	twl->twl4030_pwm_mux &= ~mask;
+	twl->twl4030_pwm_mux |= (val & mask);
+
+	/* Select PWM functionality */
+	val &= ~mask;
+	val |= bits;
+
+	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_PMBR1_REG);
+	if (ret < 0)
+		dev_err(chip->dev, "%s: Failed to request PWM\n", pwm->label);
+
+	return ret;
+}
+
+static void twl4030_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct twl_pwm_chip *twl = container_of(chip, struct twl_pwm_chip,
+						chip);
+	int ret;
+	u8 val, mask;
+
+	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_PMBR1_REG);
+	if (ret < 0) {
+		dev_err(chip->dev, "%s: Failed to read PMBR1\n", pwm->label);
+		return;
+	}
+
+	if (pwm->hwpwm)
+		/* PWM 1 */
+		mask = TWL4030_GPIO7_VIBRASYNC_PWM1_MASK;
+	else
+		/* PWM 0 */
+		mask = TWL4030_GPIO6_PWM0_MUTE_MASK;
+
+	/* Restore the MUX configuration for the PWM */
+	val &= ~mask;
+	val |= (twl->twl4030_pwm_mux & mask);
+
+	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_PMBR1_REG);
+	if (ret < 0)
+		dev_err(chip->dev, "%s: Failed to free PWM\n", pwm->label);
+}
+
+static int twl6030_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct twl_pwm_chip *twl = container_of(chip, struct twl_pwm_chip,
+						chip);
+	int ret;
+	u8 val;
+
+	val = twl->twl6030_toggle3;
+	val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXS | TWL6030_PWMXEN);
+	val &= ~TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXR);
+
+	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
+	if (ret < 0) {
+		dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
+		return ret;
+	}
+
+	twl->twl6030_toggle3 = val;
+
+	return 0;
+}
+
+static void twl6030_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct twl_pwm_chip *twl = container_of(chip, struct twl_pwm_chip,
+						chip);
+	int ret;
+	u8 val;
+
+	val = twl->twl6030_toggle3;
+	val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXR);
+	val &= ~TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXS | TWL6030_PWMXEN);
+
+	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
+	if (ret < 0) {
+		dev_err(chip->dev, "%s: Failed to read TOGGLE3\n", pwm->label);
+		return;
+	}
+
+	val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXS | TWL6030_PWMXEN);
+
+	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG);
+	if (ret < 0) {
+		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
+		return;
+	}
+
+	twl->twl6030_toggle3 = val;
+}
+
+static struct pwm_ops twl_pwm_ops = {
+	.config = twl_pwm_config,
+};
+
+static int twl_pwm_probe(struct platform_device *pdev)
+{
+	struct twl_pwm_chip *twl;
+	int ret;
+
+	twl = devm_kzalloc(&pdev->dev, sizeof(*twl), GFP_KERNEL);
+	if (!twl)
+		return -ENOMEM;
+
+	if (twl_class_is_4030()) {
+		twl_pwm_ops.enable = twl4030_pwm_enable;
+		twl_pwm_ops.disable = twl4030_pwm_disable;
+		twl_pwm_ops.request = twl4030_pwm_request;
+		twl_pwm_ops.free = twl4030_pwm_free;
+	} else {
+		twl_pwm_ops.enable = twl6030_pwm_enable;
+		twl_pwm_ops.disable = twl6030_pwm_disable;
+	}
+
+	twl->chip.dev = &pdev->dev;
+	twl->chip.ops = &twl_pwm_ops;
+	twl->chip.base = -1;
+	twl->chip.npwm = 2;
+
+	ret = pwmchip_add(&twl->chip);
+	if (ret < 0)
+		return ret;
+
+	platform_set_drvdata(pdev, twl);
+
+	return 0;
+}
+
+static int twl_pwm_remove(struct platform_device *pdev)
+{
+	struct twl_pwm_chip *twl = platform_get_drvdata(pdev);
+
+	return pwmchip_remove(&twl->chip);
+}
+
+static struct of_device_id twl_pwm_of_match[] = {
+	{ .compatible = "ti,twl4030-pwm" },
+	{ .compatible = "ti,twl6030-pwm" },
+};
+
+MODULE_DEVICE_TABLE(of, twl_pwm_of_match);
+
+static struct platform_driver twl_pwm_driver = {
+	.driver = {
+		.name = "twl-pwm",
+		.of_match_table = of_match_ptr(twl_pwm_of_match),
+	},
+	.probe = twl_pwm_probe,
+	.remove = __devexit_p(twl_pwm_remove),
+};
+module_platform_driver(twl_pwm_driver);
+
+MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@...com>");
+MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030");
+MODULE_ALIAS("platform:twl-pwm");
+MODULE_LICENSE("GPL");
-- 
1.8.0

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