[PATCH 1/3] pwm: Add mc13xxx pwm driver.
Denis Carikli
denis at eukrea.com
Wed Nov 27 10:39:29 EST 2013
Cc: Thierry Reding <thierry.reding at gmail.com>
Cc: Grant Likely <grant.likely at linaro.org>
Cc: Rob Herring <rob.herring at calxeda.com>
Cc: devicetree at vger.kernel.org
Cc: linux-pwm at vger.kernel.org
Cc: Samuel Ortiz <sameo at linux.intel.com>
Cc: Lee Jones <lee.jones at linaro.org>
Cc: Shawn Guo <shawn.guo at linaro.org>
Cc: linux-arm-kernel at lists.infradead.org
Signed-off-by: Denis Carikli <denis at eukrea.com>
---
.../devicetree/bindings/pwm/fsl,mc13xxx-pwm.txt | 19 ++
drivers/mfd/mc13xxx-core.c | 11 ++
drivers/pwm/Kconfig | 6 +
drivers/pwm/Makefile | 1 +
drivers/pwm/pwm-mc13xxx.c | 205 ++++++++++++++++++++
include/linux/mfd/mc13783.h | 2 +
6 files changed, 244 insertions(+)
create mode 100644 Documentation/devicetree/bindings/pwm/fsl,mc13xxx-pwm.txt
create mode 100644 drivers/pwm/pwm-mc13xxx.c
diff --git a/Documentation/devicetree/bindings/pwm/fsl,mc13xxx-pwm.txt b/Documentation/devicetree/bindings/pwm/fsl,mc13xxx-pwm.txt
new file mode 100644
index 0000000..a1394d0
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/fsl,mc13xxx-pwm.txt
@@ -0,0 +1,19 @@
+Freescale mc13xxx series PWM drivers.
+
+Supported PWMs:
+mc13892 series
+mc34708 series
+
+Required properties:
+- compatible: "fsl,mc13892-pwm" or "fsl,mc34708-pwm"
+- mfd: phandle to mc13xxx mfd node.
+- #pwm-cells: should be 2. See pwm.txt in this directory for a description of
+ the cells format.
+
+Example:
+
+mc13xxx_pwm: pwm {
+ compatible = "fsl,mc34708-pwm";
+ mfd = <&pmic>;
+ #pwm-cells = <2>;
+};
diff --git a/drivers/mfd/mc13xxx-core.c b/drivers/mfd/mc13xxx-core.c
index dbbf8ee..e250f16 100644
--- a/drivers/mfd/mc13xxx-core.c
+++ b/drivers/mfd/mc13xxx-core.c
@@ -133,6 +133,8 @@
#define MC13XXX_ADC2 45
+struct mc13xxx *mc13xxx_data;
+
void mc13xxx_lock(struct mc13xxx *mc13xxx)
{
if (!mutex_trylock(&mc13xxx->lock)) {
@@ -639,6 +641,12 @@ static inline int mc13xxx_probe_flags_dt(struct mc13xxx *mc13xxx)
}
#endif
+struct mc13xxx *get_mc13xxx(void)
+{
+ return mc13xxx_data;
+}
+EXPORT_SYMBOL_GPL(get_mc13xxx);
+
int mc13xxx_common_init(struct mc13xxx *mc13xxx,
struct mc13xxx_platform_data *pdata, int irq)
{
@@ -706,6 +714,9 @@ err_revision:
mc13xxx_add_subdevice(mc13xxx, "%s-pwrbutton");
}
+ /* Linux will not have to handle more than one mc13xxx pmic. */
+ mc13xxx_data = mc13xxx;
+
return 0;
}
EXPORT_SYMBOL_GPL(mc13xxx_common_init);
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index eece329..a959ecd 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -100,6 +100,12 @@ config PWM_LPC32XX
To compile this driver as a module, choose M here: the module
will be called pwm-lpc32xx.
+config PWM_MC13XXX
+ tristate "MC13XXX PWM support"
+ depends on MFD_MC13XXX
+ help
+ Generic PWM framework driver for Freescale MC13XXX pmic.
+
config PWM_MXS
tristate "Freescale MXS PWM support"
depends on ARCH_MXS && OF
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index 8b754e4..19f67d7 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -7,6 +7,7 @@ obj-$(CONFIG_PWM_EP93XX) += pwm-ep93xx.o
obj-$(CONFIG_PWM_IMX) += pwm-imx.o
obj-$(CONFIG_PWM_JZ4740) += pwm-jz4740.o
obj-$(CONFIG_PWM_LPC32XX) += pwm-lpc32xx.o
+obj-$(CONFIG_PWM_MC13XXX) += pwm-mc13xxx.o
obj-$(CONFIG_PWM_MXS) += pwm-mxs.o
obj-$(CONFIG_PWM_PCA9685) += pwm-pca9685.o
obj-$(CONFIG_PWM_PUV3) += pwm-puv3.o
diff --git a/drivers/pwm/pwm-mc13xxx.c b/drivers/pwm/pwm-mc13xxx.c
new file mode 100644
index 0000000..e60e4d8
--- /dev/null
+++ b/drivers/pwm/pwm-mc13xxx.c
@@ -0,0 +1,205 @@
+/*
+ * Copyright 2013 Eukréa Electromatique <denis at eukrea.com>
+ *
+ * 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.
+ */
+
+
+#include <linux/err.h>
+#include <linux/mfd/mc13783.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of_platform.h>
+#include <linux/pwm.h>
+#include <linux/slab.h>
+
+#define MHz(x) (1000*1000*x)
+
+#define MC13XXX_REG_PWM_CTL 55
+#define MC13XXX_BASE_CLK_FREQ (MHz(2) / 32)
+#define MC13XXX_PWM1CLKDIV_SHIFT 6
+#define MC13XXX_PWM2DUTY_SHIFT 12
+#define MC13XXX_PWMDUTYDIVISOR 32
+#define MC13XXX_PWMCLKDIVISOR 64
+#define MC13XXX_PWM_REG_SIZE 0x3f
+#define MC13XXX_MIN_PERIOD_NS (NSEC_PER_SEC / MC13XXX_BASE_CLK_FREQ)
+#define MC13XXX_MAX_PERIOD_NS (MC13XXX_PWMCLKDIVISOR * MC13XXX_MIN_PERIOD_NS)
+
+struct mc13xxx_pwm_chip {
+ struct pwm_chip pwm_chip;
+ struct mc13xxx *mcdev;
+};
+
+static inline
+struct mc13xxx_pwm_chip *to_mc13xxx_chip(struct pwm_chip *chip)
+{
+ return container_of(chip, struct mc13xxx_pwm_chip, pwm_chip);
+}
+
+static int pwm_mc13xxx_config(struct pwm_chip *chip, struct pwm_device *pwm,
+ int duty_ns, int period_ns)
+{
+ struct mc13xxx_pwm_chip *mc13xxx_chip = to_mc13xxx_chip(chip);
+ struct mc13xxx *mcdev = mc13xxx_chip->mcdev;
+ struct device *dev = mc13xxx_chip->pwm_chip.dev;
+ u32 offset;
+ u32 mask = MC13XXX_PWM_REG_SIZE;
+ u32 val;
+ int ret;
+ int duty_cycle;
+ int min_duty_cycle;
+ int period_cycle;
+ unsigned long period = period_ns;
+
+ dev_dbg(dev, "requested duty_ns=%d and period_ns=%d\n",
+ duty_ns, period_ns);
+
+ /* period */
+ if (period < MC13XXX_MIN_PERIOD_NS) {
+ dev_warn(dev, "period was under the range.\n");
+ period = MC13XXX_MIN_PERIOD_NS;
+ }
+
+ if (period > MC13XXX_MAX_PERIOD_NS) {
+ dev_warn(dev, "period was over the range.\n");
+ period = MC13XXX_MAX_PERIOD_NS;
+ }
+
+ period_cycle = DIV_ROUND_UP(NSEC_PER_SEC, period);
+ period_cycle = DIV_ROUND_UP(MC13XXX_BASE_CLK_FREQ, period_cycle);
+ period_cycle--;
+
+ offset = MC13XXX_REG_PWM_CTL + pwm->hwpwm * MC13XXX_PWM2DUTY_SHIFT +
+ MC13XXX_PWM1CLKDIV_SHIFT;
+
+ mc13xxx_lock(mcdev);
+ ret = mc13xxx_reg_read(mcdev, offset, &val);
+ val &= ~mask;
+ val += (period_cycle & mask);
+ ret = mc13xxx_reg_write(mcdev, offset, val);
+ mc13xxx_unlock(mcdev);
+
+ /* duty cycle */
+ min_duty_cycle = DIV_ROUND_UP(period, 32);
+
+ if (duty_ns < min_duty_cycle) {
+ dev_warn(dev, "duty cycle is under the range.\n");
+ duty_cycle = 0;
+ } else if (duty_ns > period) {
+ dev_warn(dev, "duty cycle is over the range.\n");
+ duty_cycle = 32;
+ } else {
+ duty_cycle = 32 * period;
+ duty_cycle = DIV_ROUND_UP(period, duty_ns);
+ duty_cycle--;
+ duty_cycle = 32 - duty_cycle;
+ }
+
+ offset = MC13XXX_REG_PWM_CTL + pwm->hwpwm * MC13XXX_PWM2DUTY_SHIFT;
+
+ mc13xxx_lock(mcdev);
+ ret = mc13xxx_reg_read(mcdev, offset, &val);
+ val &= ~mask;
+ val += (duty_cycle & mask);
+ ret = mc13xxx_reg_write(mcdev, offset, val);
+ mc13xxx_unlock(mcdev);
+
+ return 0;
+}
+
+static int pwm_mc13xxx_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ /* The hardware doesn't need an enable */
+
+ return 0;
+}
+
+static void pwm_mc13xxx_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ /* The hardware doesn't need a disable */
+}
+
+static const struct pwm_ops pwm_mc13xxx_ops = {
+ .enable = pwm_mc13xxx_enable,
+ .disable = pwm_mc13xxx_disable,
+ .config = pwm_mc13xxx_config,
+ .owner = THIS_MODULE,
+};
+
+static int pwm_mc13xxx_probe(struct platform_device *pdev)
+{
+ struct mc13xxx_pwm_chip *chip;
+ struct mc13xxx *mcdev;
+ int err;
+
+ mcdev = get_mc13xxx();
+ if (!mcdev) {
+ dev_err(&pdev->dev, "failed to find mc13xxx pmic.\n");
+ return -EINVAL;
+ }
+
+ chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
+ if (chip == NULL) {
+ dev_err(&pdev->dev, "failed to allocate memory\n");
+ return -ENOMEM;
+ }
+
+ chip->pwm_chip.dev = &pdev->dev;
+ chip->pwm_chip.ops = &pwm_mc13xxx_ops;
+ chip->pwm_chip.base = pdev->id;
+ chip->pwm_chip.npwm = 2;
+ chip->mcdev = mcdev;
+
+ err = pwmchip_add(&chip->pwm_chip);
+ if (err < 0)
+ return err;
+
+ platform_set_drvdata(pdev, chip);
+
+ return 0;
+}
+
+static int pwm_mc13xxx_remove(struct platform_device *pdev)
+{
+ struct mc13xxx_pwm_chip *chip = platform_get_drvdata(pdev);
+ int ret;
+
+ ret = pwmchip_remove(&chip->pwm_chip);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id pwm_mc13xxx_of_match[] = {
+ { .compatible = "fsl,mc13892-pwm" },
+ { .compatible = "fsl,mc34708-pwm" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, pwm_mc13xxx_of_match);
+#endif
+
+static struct platform_driver pwm_mc13xxx_driver = {
+ .driver = {
+ .name = "mc13xxx-pwm",
+ .of_match_table = of_match_ptr(pwm_mc13xxx_of_match),
+ .owner = THIS_MODULE,
+ },
+ .probe = pwm_mc13xxx_probe,
+ .remove = pwm_mc13xxx_remove,
+};
+
+module_platform_driver(pwm_mc13xxx_driver);
+
+MODULE_AUTHOR("Denis Carikli <denis at eukrea.com>");
+MODULE_DESCRIPTION("mc13xxx Pulse Width Modulation Driver");
+MODULE_ALIAS("platform:mc13xxx-pwm");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/mfd/mc13783.h b/include/linux/mfd/mc13783.h
index a8eeda7..ec934e8 100644
--- a/include/linux/mfd/mc13783.h
+++ b/include/linux/mfd/mc13783.h
@@ -88,4 +88,6 @@
#define MC13783_IRQ_AHSSHORT 45
#define MC13783_NUM_IRQ MC13XXX_NUM_IRQ
+struct mc13xxx *get_mc13xxx(void);
+
#endif /* ifndef __LINUX_MFD_MC13783_H */
--
1.7.9.5
More information about the linux-arm-kernel
mailing list