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authorLinus Torvalds <torvalds@linux-foundation.org>2012-10-10 20:15:24 +0900
committerLinus Torvalds <torvalds@linux-foundation.org>2012-10-10 20:15:24 +0900
commit2474542f64432398f503373f53bdf620491bcfa8 (patch)
tree3c9744b138c2158757530814b35c23eed31cf6ce /drivers/pwm/pwm-ab8500.c
parentc7a6ced9d8e8411bdafe83998474d185a79badc3 (diff)
parent85f8879ca4f3d26a7f473522101fb74a79bda3f2 (diff)
downloadop-kernel-dev-2474542f64432398f503373f53bdf620491bcfa8.zip
op-kernel-dev-2474542f64432398f503373f53bdf620491bcfa8.tar.gz
Merge tag 'for-3.7-rc1' of git://gitorious.org/linux-pwm/linux-pwm
Pull pwm changes from Thierry Reding: "All legacy PWM providers have now been moved to the PWM subsystem. The plan for 3.8 is to adapt all board files to provide a lookup table for PWM devices in order to get rid of the global namespace. Subsequently, users of the legacy pwm_request() and pwm_free() functions can be migrated to the new pwm_get() and pwm_put() functions. Once this has been completed, the legacy API and the compatibility code in the core can be removed. In addition to the above, these changes also add support for configuring the polarity of a PWM signal (currently only supported on ECAP and EHRPWM) and include a much needed rework of the i.MX driver. Managed functions to obtain and release a PWM device (devm_pwm_get() and devm_pwm_put()) have been added and the pwm-backlight driver has been updated to use them. If the PWM subsystem hasn't been enabled, dummy functions are provided that allow the subsystem to safely compile out. Some common checks on input parameters have been moved to the core and removed from the drivers. Finally, a small fix corrects the description of the PWM specifier's second cell in the device tree representation." * tag 'for-3.7-rc1' of git://gitorious.org/linux-pwm/linux-pwm: (23 commits) pwm: dt: Fix description of second PWM cell pwm: Check for negative duty-cycle and period pwm: Add Ingenic JZ4740 support MIPS: JZ4740: Export timer API pwm: Move PUV3 PWM driver to PWM framework unicore32: pwm: Use managed resource allocations unicore32: pwm: Remove unnecessary indirection unicore32: pwm: Use module_platform_driver() unicore32: pwm: Properly remap memory-mapped registers pwm-backlight: Use devm_pwm_get() instead of pwm_get() pwm: Move AB8500 PWM driver to PWM framework pwm: Fix compilation error when CONFIG_PWM is not defined pwm: i.MX: fix clock lookup pwm: i.MX: use per clock unconditionally pwm: i.MX: add devicetree support pwm: i.MX: Use module_platform_driver pwm: i.MX: add functions to enable/disable pwm. pwm: i.MX: remove unnecessary if in pwm_[en|dis]able pwm: i.MX: factor out SoC specific functions pwm: pwm-tiehrpwm: Add support for configuring polarity of PWM ...
Diffstat (limited to 'drivers/pwm/pwm-ab8500.c')
-rw-r--r--drivers/pwm/pwm-ab8500.c153
1 files changed, 153 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-ab8500.c b/drivers/pwm/pwm-ab8500.c
new file mode 100644
index 0000000..cfb72ca
--- /dev/null
+++ b/drivers/pwm/pwm-ab8500.c
@@ -0,0 +1,153 @@
+/*
+ * 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
+
+/* backlight driver constants */
+#define ENABLE_PWM 1
+#define DISABLE_PWM 0
+
+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), ENABLE_PWM);
+ if (ret < 0)
+ dev_err(chip->dev, "%s: Failed to disable 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), DISABLE_PWM);
+ if (ret < 0)
+ dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n",
+ pwm->label, ret);
+ return;
+}
+
+static const struct pwm_ops ab8500_pwm_ops = {
+ .config = ab8500_pwm_config,
+ .enable = ab8500_pwm_enable,
+ .disable = ab8500_pwm_disable,
+};
+
+static int __devinit 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 = kzalloc(sizeof(*ab8500), GFP_KERNEL);
+ if (ab8500 == NULL) {
+ dev_err(&pdev->dev, "failed to allocate memory\n");
+ 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) {
+ kfree(ab8500);
+ return err;
+ }
+
+ dev_dbg(&pdev->dev, "pwm probe successful\n");
+ platform_set_drvdata(pdev, ab8500);
+
+ return 0;
+}
+
+static int __devexit 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");
+ kfree(ab8500);
+
+ 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),
+};
+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");
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