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Message-Id: <1341931090-18296-1-git-send-email-aletes.xgr@gmail.com>
Date: Tue, 10 Jul 2012 11:38:10 -0300
From: Alexandre Pereira da Silva <aletes.xgr@...il.com>
To: Roland Stigge <stigge@...com.de>,
Alexandre Pereira da Silva <aletes.xgr@...il.com>,
Thierry Reding <thierry.reding@...onic-design.de>,
Grant Likely <grant.likely@...retlab.ca>,
Rob Herring <rob.herring@...xeda.com>,
Rob Landley <rob@...dley.net>, linux-kernel@...r.kernel.org,
devicetree-discuss@...ts.ozlabs.org, linux-doc@...r.kernel.org
Subject: [PATCH v3] PWM: add lpc32xx PWM support
Add lpc32xx SOC PWM driver.
Signed-off-by: Alexandre Pereira da Silva <aletes.xgr@...il.com>
---
Changes since v2:
* Update commit message
* Change the driver to handle the two PWM's of the SOC
* Disable clock on removal
Changes since v1:
* Style fixes
* Better error handling
* Improved Kconfig and DT descriptions
.../devicetree/bindings/pwm/lpc32xx-pwm.txt | 12 ++
drivers/pwm/Kconfig | 10 ++
drivers/pwm/Makefile | 1 +
drivers/pwm/pwm-lpc32xx.c | 148 ++++++++++++++++++++
4 files changed, 171 insertions(+)
create mode 100644 Documentation/devicetree/bindings/pwm/lpc32xx-pwm.txt
create mode 100644 drivers/pwm/pwm-lpc32xx.c
diff --git a/Documentation/devicetree/bindings/pwm/lpc32xx-pwm.txt b/Documentation/devicetree/bindings/pwm/lpc32xx-pwm.txt
new file mode 100644
index 0000000..cfe1db3
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/lpc32xx-pwm.txt
@@ -0,0 +1,12 @@
+LPC32XX PWM controller
+
+Required properties:
+- compatible: should be "nxp,lpc3220-pwm"
+- reg: physical base address and length of the controller's registers
+
+Examples:
+
+pwm@...005C000 {
+ compatible = "nxp,lpc3220-pwm";
+ reg = <0x4005C000 0x8>;
+};
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 0b2800f..94e176e 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -28,6 +28,16 @@ config PWM_IMX
To compile this driver as a module, choose M here: the module
will be called pwm-imx.
+config PWM_LPC32XX
+ tristate "LPC32XX PWM support"
+ depends on ARCH_LPC32XX
+ help
+ Generic PWM framework driver for LPC32XX. The LPC32XX SOC has two
+ PWM controllers.
+
+ To compile this driver as a module, choose M here: the module
+ will be called pwm-lpc32xx.
+
config PWM_MXS
tristate "Freescale MXS PWM support"
depends on ARCH_MXS && OF
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index cec2500..5459702 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -1,6 +1,7 @@
obj-$(CONFIG_PWM) += core.o
obj-$(CONFIG_PWM_BFIN) += pwm-bfin.o
obj-$(CONFIG_PWM_IMX) += pwm-imx.o
+obj-$(CONFIG_PWM_LPC32XX) += pwm-lpc32xx.o
obj-$(CONFIG_PWM_MXS) += pwm-mxs.o
obj-$(CONFIG_PWM_PXA) += pwm-pxa.o
obj-$(CONFIG_PWM_SAMSUNG) += pwm-samsung.o
diff --git a/drivers/pwm/pwm-lpc32xx.c b/drivers/pwm/pwm-lpc32xx.c
new file mode 100644
index 0000000..adb87f0
--- /dev/null
+++ b/drivers/pwm/pwm-lpc32xx.c
@@ -0,0 +1,148 @@
+/*
+ * Copyright 2012 Alexandre Pereira da Silva <aletes.xgr@...il.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; version 2.
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/slab.h>
+
+struct lpc32xx_pwm_chip {
+ struct pwm_chip chip;
+ struct clk *clk;
+ void __iomem *base;
+};
+
+#define PWM_ENABLE (1 << 31)
+#define PWM_RELOADV(x) (((x) & 0xFF) << 8)
+#define PWM_DUTY(x) ((x) & 0xFF)
+
+#define to_lpc32xx_pwm_chip(_chip) \
+ container_of(_chip, struct lpc32xx_pwm_chip, chip)
+
+static int lpc32xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+ int duty_ns, int period_ns)
+{
+ struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip);
+ unsigned long long c;
+ int period_cycles, duty_cycles;
+
+ c = clk_get_rate(lpc32xx->clk) / 256;
+ c = c * period_ns;
+ do_div(c, NSEC_PER_SEC);
+
+ /* Handle high and low extremes */
+ if (c == 0)
+ c = 1;
+ if (c > 255)
+ c = 0; /* 0 set division by 256 */
+ period_cycles = c;
+
+ c = 256 * duty_ns;
+ do_div(c, period_ns);
+ duty_cycles = c;
+
+ writel(PWM_ENABLE | PWM_RELOADV(period_cycles) | PWM_DUTY(duty_cycles),
+ lpc32xx->base + (pwm->hwpwm << 2));
+
+ return 0;
+}
+
+static int lpc32xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip);
+
+ return clk_enable(lpc32xx->clk);
+}
+
+static void lpc32xx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip);
+
+ writel(0, lpc32xx->base + (pwm->hwpwm << 2));
+ clk_disable(lpc32xx->clk);
+}
+
+static const struct pwm_ops lpc32xx_pwm_ops = {
+ .config = lpc32xx_pwm_config,
+ .enable = lpc32xx_pwm_enable,
+ .disable = lpc32xx_pwm_disable,
+ .owner = THIS_MODULE,
+};
+
+static int lpc32xx_pwm_probe(struct platform_device *pdev)
+{
+ struct lpc32xx_pwm_chip *lpc32xx;
+ struct resource *res;
+ int ret;
+
+ lpc32xx = devm_kzalloc(&pdev->dev, sizeof(*lpc32xx), GFP_KERNEL);
+ if (!lpc32xx)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -EINVAL;
+
+ lpc32xx->base = devm_request_and_ioremap(&pdev->dev, res);
+ if (!lpc32xx->base)
+ return -EADDRNOTAVAIL;
+
+ lpc32xx->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(lpc32xx->clk))
+ return PTR_ERR(lpc32xx->clk);
+
+ lpc32xx->chip.dev = &pdev->dev;
+ lpc32xx->chip.ops = &lpc32xx_pwm_ops;
+ lpc32xx->chip.npwm = 2;
+
+ ret = pwmchip_add(&lpc32xx->chip);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to add PWM chip, error %d\n", ret);
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, lpc32xx);
+
+ return 0;
+}
+
+static int __devexit lpc32xx_pwm_remove(struct platform_device *pdev)
+{
+ struct lpc32xx_pwm_chip *lpc32xx = platform_get_drvdata(pdev);
+
+ clk_disable(lpc32xx->clk);
+ return pwmchip_remove(&lpc32xx->chip);
+}
+
+static struct of_device_id lpc32xx_pwm_dt_ids[] = {
+ { .compatible = "nxp,lpc3220-pwm", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, lpc32xx_pwm_dt_ids);
+
+static struct platform_driver lpc32xx_pwm_driver = {
+ .driver = {
+ .name = "lpc32xx-pwm",
+ .of_match_table = of_match_ptr(lpc32xx_pwm_dt_ids),
+ },
+ .probe = lpc32xx_pwm_probe,
+ .remove = __devexit_p(lpc32xx_pwm_remove),
+};
+module_platform_driver(lpc32xx_pwm_driver);
+
+MODULE_ALIAS("platform:lpc32xx-pwm");
+MODULE_AUTHOR("Alexandre Pereira da Silva <aletes.xgr@...il.com>");
+MODULE_DESCRIPTION("LPC32XX PWM Driver");
+MODULE_LICENSE("GPL v2");
--
1.7.10
--
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