pwm: Move PUV3 PWM driver to PWM framework

This commit moves the driver to drivers/pwm and converts it to the new
PWM framework.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Tested-by: Qin Rui <qinrui@mprc.pku.edu.cn>
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn>

3 files changed, 172 insertions, 1 deletions

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 99a738182bf5..d954c72e242e 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -1,6 +1,6 @@
 menuconfig PWM
         bool "Pulse-Width Modulation (PWM) Support"
-        depends on !MACH_JZ4740 && !PUV3_PWM
+        depends on !MACH_JZ4740
         help
           Generic Pulse-Width Modulation (PWM) support.
 
@@ -76,6 +76,15 @@ config PWM_MXS
           To compile this driver as a module, choose M here: the module
           will be called pwm-mxs.
 
+config PWM_PUV3
+        tristate "PKUnity NetBook-0916 PWM support"
+        depends on ARCH_PUV3
+        help
+          Generic PWM framework driver for PKUnity NetBook-0916.
+
+          To compile this driver as a module, choose M here: the module
+          will be called pwm-puv3.
+
 config PWM_PXA
         tristate "PXA PWM support"
         depends on ARCH_PXA
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index bebc6ff904b9..360aad8fa3ae 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -4,6 +4,7 @@ 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-$(CONFIG_PWM_PUV3)          += pwm-puv3.o
 obj-$(CONFIG_PWM_PXA)           += pwm-pxa.o
 obj-$(CONFIG_PWM_SAMSUNG)       += pwm-samsung.o
 obj-$(CONFIG_PWM_TEGRA)         += pwm-tegra.o
diff --git a/drivers/pwm/pwm-puv3.c b/drivers/pwm/pwm-puv3.c
new file mode 100644
index 000000000000..2a93f37c46ad
--- /dev/null
+++ b/drivers/pwm/pwm-puv3.c
@@ -0,0 +1,161 @@
+/*
+ * linux/arch/unicore32/kernel/pwm.c
+ *
+ * Code specific to PKUnity SoC and UniCore ISA
+ *
+ *      Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn>
+ *      Copyright (C) 2001-2010 Guan Xuetao
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/pwm.h>
+
+#include <asm/div64.h>
+#include <mach/hardware.h>
+
+struct puv3_pwm_chip {
+        struct pwm_chip chip;
+        void __iomem *base;
+        struct clk *clk;
+        bool enabled;
+};
+
+static inline struct puv3_pwm_chip *to_puv3(struct pwm_chip *chip)
+{
+        return container_of(chip, struct puv3_pwm_chip, chip);
+}
+
+/*
+ * period_ns = 10^9 * (PRESCALE + 1) * (PV + 1) / PWM_CLK_RATE
+ * duty_ns   = 10^9 * (PRESCALE + 1) * DC / PWM_CLK_RATE
+ */
+static int puv3_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+                           int duty_ns, int period_ns)
+{
+        unsigned long period_cycles, prescale, pv, dc;
+        struct puv3_pwm_chip *puv3 = to_puv3(chip);
+        unsigned long long c;
+
+        c = clk_get_rate(puv3->clk);
+        c = c * period_ns;
+        do_div(c, 1000000000);
+        period_cycles = c;
+
+        if (period_cycles < 1)
+                period_cycles = 1;
+
+        prescale = (period_cycles - 1) / 1024;
+        pv = period_cycles / (prescale + 1) - 1;
+
+        if (prescale > 63)
+                return -EINVAL;
+
+        if (duty_ns == period_ns)
+                dc = OST_PWMDCCR_FDCYCLE;
+        else
+                dc = (pv + 1) * duty_ns / period_ns;
+
+        /*
+         * NOTE: the clock to PWM has to be enabled first
+         * before writing to the registers
+         */
+        clk_prepare_enable(puv3->clk);
+
+        writel(prescale, puv3->base + OST_PWM_PWCR);
+        writel(pv - dc, puv3->base + OST_PWM_DCCR);
+        writel(pv, puv3->base + OST_PWM_PCR);
+
+        clk_disable_unprepare(puv3->clk);
+
+        return 0;
+}
+
+static int puv3_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+        struct puv3_pwm_chip *puv3 = to_puv3(chip);
+
+        return clk_prepare_enable(puv3->clk);
+}
+
+static void puv3_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+        struct puv3_pwm_chip *puv3 = to_puv3(chip);
+
+        clk_disable_unprepare(puv3->clk);
+}
+
+static const struct pwm_ops puv3_pwm_ops = {
+        .config = puv3_pwm_config,
+        .enable = puv3_pwm_enable,
+        .disable = puv3_pwm_disable,
+        .owner = THIS_MODULE,
+};
+
+static int __devinit pwm_probe(struct platform_device *pdev)
+{
+        struct puv3_pwm_chip *puv3;
+        struct resource *r;
+        int ret;
+
+        puv3 = devm_kzalloc(&pdev->dev, sizeof(*puv3), GFP_KERNEL);
+        if (puv3 == NULL) {
+                dev_err(&pdev->dev, "failed to allocate memory\n");
+                return -ENOMEM;
+        }
+
+        puv3->clk = devm_clk_get(&pdev->dev, "OST_CLK");
+        if (IS_ERR(puv3->clk))
+                return PTR_ERR(puv3->clk);
+
+        r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (r == NULL) {
+                dev_err(&pdev->dev, "no memory resource defined\n");
+                return -ENODEV;
+        }
+
+        puv3->base = devm_request_and_ioremap(&pdev->dev, r);
+        if (puv3->base == NULL)
+                return -EADDRNOTAVAIL;
+
+        puv3->chip.dev = &pdev->dev;
+        puv3->chip.ops = &puv3_pwm_ops;
+        puv3->chip.base = -1;
+        puv3->chip.npwm = 1;
+
+        ret = pwmchip_add(&puv3->chip);
+        if (ret < 0) {
+                dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
+                return ret;
+        }
+
+        platform_set_drvdata(pdev, puv3);
+        return 0;
+}
+
+static int __devexit pwm_remove(struct platform_device *pdev)
+{
+        struct puv3_pwm_chip *puv3 = platform_get_drvdata(pdev);
+
+        return pwmchip_remove(&puv3->chip);
+}
+
+static struct platform_driver puv3_pwm_driver = {
+        .driver = {
+                .name = "PKUnity-v3-PWM",
+        },
+        .probe = pwm_probe,
+        .remove = __devexit_p(pwm_remove),
+};
+module_platform_driver(puv3_pwm_driver);
+
+MODULE_LICENSE("GPL v2");