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authorThierry Reding <thierry.reding@avionic-design.de>2012-08-31 08:29:24 +0200
committerThierry Reding <thierry.reding@avionic-design.de>2012-10-05 20:56:41 +0200
commit79c11b6fa0b225ac165e79e821d50e70f563645f (patch)
tree05a7b6a2a87f05780b2a12a2e821c44336d73e75 /drivers/pwm/pwm-puv3.c
parent5384e27317016bd30aa7a7a7513f76ce7caa3b09 (diff)
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>
Diffstat (limited to 'drivers/pwm/pwm-puv3.c')
-rw-r--r--drivers/pwm/pwm-puv3.c161
1 files changed, 161 insertions, 0 deletions
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");

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