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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/drivers/pwm/pwm-lpc32xx.c
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/drivers/pwm/pwm-lpc32xx.c')
-rw-r--r--kernel/drivers/pwm/pwm-lpc32xx.c181
1 files changed, 181 insertions, 0 deletions
diff --git a/kernel/drivers/pwm/pwm-lpc32xx.c b/kernel/drivers/pwm/pwm-lpc32xx.c
new file mode 100644
index 000000000..9fde60ce8
--- /dev/null
+++ b/kernel/drivers/pwm/pwm-lpc32xx.c
@@ -0,0 +1,181 @@
+/*
+ * Copyright 2012 Alexandre Pereira da Silva <aletes.xgr@gmail.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;
+ u32 val;
+
+ 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;
+
+ /* The duty-cycle value is as follows:
+ *
+ * DUTY-CYCLE HIGH LEVEL
+ * 1 99.9%
+ * 25 90.0%
+ * 128 50.0%
+ * 220 10.0%
+ * 255 0.1%
+ * 0 0.0%
+ *
+ * In other words, the register value is duty-cycle % 256 with
+ * duty-cycle in the range 1-256.
+ */
+ c = 256 * duty_ns;
+ do_div(c, period_ns);
+ if (c > 255)
+ c = 255;
+ duty_cycles = 256 - c;
+
+ val = readl(lpc32xx->base + (pwm->hwpwm << 2));
+ val &= ~0xFFFF;
+ val |= PWM_RELOADV(period_cycles) | PWM_DUTY(duty_cycles);
+ writel(val, 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);
+ u32 val;
+ int ret;
+
+ ret = clk_enable(lpc32xx->clk);
+ if (ret)
+ return ret;
+
+ val = readl(lpc32xx->base + (pwm->hwpwm << 2));
+ val |= PWM_ENABLE;
+ writel(val, lpc32xx->base + (pwm->hwpwm << 2));
+
+ return 0;
+}
+
+static void lpc32xx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip);
+ u32 val;
+
+ val = readl(lpc32xx->base + (pwm->hwpwm << 2));
+ val &= ~PWM_ENABLE;
+ writel(val, 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);
+ lpc32xx->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(lpc32xx->base))
+ return PTR_ERR(lpc32xx->base);
+
+ 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;
+ lpc32xx->chip.base = -1;
+
+ 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 lpc32xx_pwm_remove(struct platform_device *pdev)
+{
+ struct lpc32xx_pwm_chip *lpc32xx = platform_get_drvdata(pdev);
+ unsigned int i;
+
+ for (i = 0; i < lpc32xx->chip.npwm; i++)
+ pwm_disable(&lpc32xx->chip.pwms[i]);
+
+ return pwmchip_remove(&lpc32xx->chip);
+}
+
+static const 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 = lpc32xx_pwm_dt_ids,
+ },
+ .probe = lpc32xx_pwm_probe,
+ .remove = lpc32xx_pwm_remove,
+};
+module_platform_driver(lpc32xx_pwm_driver);
+
+MODULE_ALIAS("platform:lpc32xx-pwm");
+MODULE_AUTHOR("Alexandre Pereira da Silva <aletes.xgr@gmail.com>");
+MODULE_DESCRIPTION("LPC32XX PWM Driver");
+MODULE_LICENSE("GPL v2");