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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/pwm/pwm-ab8500.c
Initial import
Diffstat (limited to 'drivers/pwm/pwm-ab8500.c')
-rw-r--r--drivers/pwm/pwm-ab8500.c143
1 files changed, 143 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-ab8500.c b/drivers/pwm/pwm-ab8500.c
new file mode 100644
index 000000000..f39399273
--- /dev/null
+++ b/drivers/pwm/pwm-ab8500.c
@@ -0,0 +1,143 @@
+/*
+ * 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/abx500.h>
+#include <linux/mfd/abx500/ab8500.h>
+#include <linux/module.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
+
+struct ab8500_pwm_chip {
+ struct pwm_chip chip;
+};
+
+static int ab8500_pwm_config(struct pwm_chip *chip, 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 + ((chip->base - 1) * 2);
+
+ ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC,
+ reg, (u8)lower_val);
+ if (ret < 0)
+ return ret;
+ ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC,
+ (reg + 1), (u8)higher_val);
+
+ return ret;
+}
+
+static int ab8500_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ int ret;
+
+ ret = abx500_mask_and_set_register_interruptible(chip->dev,
+ AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
+ 1 << (chip->base - 1), 1 << (chip->base - 1));
+ if (ret < 0)
+ dev_err(chip->dev, "%s: Failed to enable PWM, Error %d\n",
+ pwm->label, ret);
+ return ret;
+}
+
+static void ab8500_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ int ret;
+
+ ret = abx500_mask_and_set_register_interruptible(chip->dev,
+ AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
+ 1 << (chip->base - 1), 0);
+ if (ret < 0)
+ dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n",
+ pwm->label, ret);
+}
+
+static const struct pwm_ops ab8500_pwm_ops = {
+ .config = ab8500_pwm_config,
+ .enable = ab8500_pwm_enable,
+ .disable = ab8500_pwm_disable,
+ .owner = THIS_MODULE,
+};
+
+static int ab8500_pwm_probe(struct platform_device *pdev)
+{
+ struct ab8500_pwm_chip *ab8500;
+ int err;
+
+ /*
+ * Nothing to be done in probe, this is required to get the
+ * device which is required for ab8500 read and write
+ */
+ ab8500 = devm_kzalloc(&pdev->dev, sizeof(*ab8500), GFP_KERNEL);
+ if (ab8500 == NULL)
+ return -ENOMEM;
+
+ ab8500->chip.dev = &pdev->dev;
+ ab8500->chip.ops = &ab8500_pwm_ops;
+ ab8500->chip.base = pdev->id;
+ ab8500->chip.npwm = 1;
+
+ err = pwmchip_add(&ab8500->chip);
+ if (err < 0)
+ return err;
+
+ dev_dbg(&pdev->dev, "pwm probe successful\n");
+ platform_set_drvdata(pdev, ab8500);
+
+ return 0;
+}
+
+static int ab8500_pwm_remove(struct platform_device *pdev)
+{
+ struct ab8500_pwm_chip *ab8500 = platform_get_drvdata(pdev);
+ int err;
+
+ err = pwmchip_remove(&ab8500->chip);
+ if (err < 0)
+ return err;
+
+ dev_dbg(&pdev->dev, "pwm driver removed\n");
+
+ return 0;
+}
+
+static struct platform_driver ab8500_pwm_driver = {
+ .driver = {
+ .name = "ab8500-pwm",
+ },
+ .probe = ab8500_pwm_probe,
+ .remove = ab8500_pwm_remove,
+};
+module_platform_driver(ab8500_pwm_driver);
+
+MODULE_AUTHOR("Arun MURTHY <arun.murthy@stericsson.com>");
+MODULE_DESCRIPTION("AB8500 Pulse Width Modulation Driver");
+MODULE_ALIAS("platform:ab8500-pwm");
+MODULE_LICENSE("GPL v2");