Merge tag 'pwm/for-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm updates from Thierry Reding:
 "This round contains a couple of new drivers for the Marvell Berlin
  family of SoCs, various SoCs from Renesas and Broadcom as well as the
  backlight PWM present on MediaTek SoCs.

  Further existing drivers are extended to support a wider range of
  hardware.

  The remaining patches are minor fixes and cleanups across the board.

  Note that one of the patches included in this pull request is against
  arch/unicore32.  I've included it here because I couldn't get a
  response from Guan Xuetao and I consider the change low-risk.
  Equivalent patches have been merged and tested in Samsung and PXA
  trees.  The goal is to finally get rid of legacy code paths that have
  repeatedly been causing headaches"

* tag 'pwm/for-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (24 commits)
  pwm: sunxi: Fix whitespace issue
  pwm: sysfs: Make use of the DEVICE_ATTR_[RW][WO] macro's
  pwm: sysfs: Remove unnecessary temporary variable
  unicore32: nb0916: Use PWM lookup table
  pwm: pwm-rcar: Revise the device tree binding document about compatible
  pwm: Return -ENODEV if no PWM lookup match is found
  pwm: sun4i: Add support for PWM controller on sun5i SoCs
  pwm: Set enable state properly on failed call to enable
  pwm: lpss: Add support for runtime PM
  pwm: lpss: Add more Intel Broxton IDs
  pwm: lpss: Support all four PWMs on Intel Broxton
  pwm: lpss: Add support for multiple PWMs
  pwm-pca9685: enable ACPI device found on Galileo Gen2
  pwm: Add MediaTek display PWM driver support
  dt-bindings: pwm: Add MediaTek display PWM bindings
  pwm: tipwmss: Enable on TI DRA7x and AM437x
  pwm: atmel-hlcdc: add sama5d2 SoC support.
  pwm: Add Broadcom BCM7038 PWM controller support
  Documentation: dt: add Broadcom BCM7038 PWM controller binding
  pwm: Add support for R-Car PWM Timer
  ...

1 files changed, 343 insertions, 0 deletions

diff --git a/drivers/pwm/pwm-brcmstb.c b/drivers/pwm/pwm-brcmstb.c
new file mode 100644
index 000000000000..423ce087cd9c
--- /dev/null
+++ b/drivers/pwm/pwm-brcmstb.c
@@ -0,0 +1,343 @@
+/*
+ * Broadcom BCM7038 PWM driver
+ * Author: Florian Fainelli
+ *
+ * Copyright (C) 2015 Broadcom Corporation
+ *
+ * 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.
+ */
+
+#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
+
+#include <linux/clk.h>
+#include <linux/export.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/spinlock.h>
+
+#define PWM_CTRL		0x00
+#define  CTRL_START		BIT(0)
+#define  CTRL_OEB		BIT(1)
+#define  CTRL_FORCE_HIGH	BIT(2)
+#define  CTRL_OPENDRAIN		BIT(3)
+#define  CTRL_CHAN_OFFS		4
+
+#define PWM_CTRL2		0x04
+#define  CTRL2_OUT_SELECT	BIT(0)
+
+#define PWM_CH_SIZE		0x8
+
+#define PWM_CWORD_MSB(ch)	(0x08 + ((ch) * PWM_CH_SIZE))
+#define PWM_CWORD_LSB(ch)	(0x0c + ((ch) * PWM_CH_SIZE))
+
+/* Number of bits for the CWORD value */
+#define CWORD_BIT_SIZE		16
+
+/*
+ * Maximum control word value allowed when variable-frequency PWM is used as a
+ * clock for the constant-frequency PMW.
+ */
+#define CONST_VAR_F_MAX		32768
+#define CONST_VAR_F_MIN		1
+
+#define PWM_ON(ch)		(0x18 + ((ch) * PWM_CH_SIZE))
+#define  PWM_ON_MIN		1
+#define PWM_PERIOD(ch)		(0x1c + ((ch) * PWM_CH_SIZE))
+#define  PWM_PERIOD_MIN		0
+
+#define PWM_ON_PERIOD_MAX	0xff
+
+struct brcmstb_pwm {
+	void __iomem *base;
+	spinlock_t lock;
+	struct clk *clk;
+	struct pwm_chip chip;
+};
+
+static inline u32 brcmstb_pwm_readl(struct brcmstb_pwm *p,
+				    unsigned int offset)
+{
+	if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
+		return __raw_readl(p->base + offset);
+	else
+		return readl_relaxed(p->base + offset);
+}
+
+static inline void brcmstb_pwm_writel(struct brcmstb_pwm *p, u32 value,
+				      unsigned int offset)
+{
+	if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
+		__raw_writel(value, p->base + offset);
+	else
+		writel_relaxed(value, p->base + offset);
+}
+
+static inline struct brcmstb_pwm *to_brcmstb_pwm(struct pwm_chip *chip)
+{
+	return container_of(chip, struct brcmstb_pwm, chip);
+}
+
+/*
+ * Fv is derived from the variable frequency output. The variable frequency
+ * output is configured using this formula:
+ *
+ * W = cword, if cword < 2 ^ 15 else 16-bit 2's complement of cword
+ *
+ * Fv = W x 2 ^ -16 x 27Mhz (reference clock)
+ *
+ * The period is: (period + 1) / Fv and "on" time is on / (period + 1)
+ *
+ * The PWM core framework specifies that the "duty_ns" parameter is in fact the
+ * "on" time, so this translates directly into our HW programming here.
+ */
+static int brcmstb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+			      int duty_ns, int period_ns)
+{
+	struct brcmstb_pwm *p = to_brcmstb_pwm(chip);
+	unsigned long pc, dc, cword = CONST_VAR_F_MAX;
+	unsigned int channel = pwm->hwpwm;
+	u32 value;
+
+	/*
+	 * If asking for a duty_ns equal to period_ns, we need to substract
+	 * the period value by 1 to make it shorter than the "on" time and
+	 * produce a flat 100% duty cycle signal, and max out the "on" time
+	 */
+	if (duty_ns == period_ns) {
+		dc = PWM_ON_PERIOD_MAX;
+		pc = PWM_ON_PERIOD_MAX - 1;
+		goto done;
+	}
+
+	while (1) {
+		u64 rate, tmp;
+
+		/*
+		 * Calculate the base rate from base frequency and current
+		 * cword
+		 */
+		rate = (u64)clk_get_rate(p->clk) * (u64)cword;
+		do_div(rate, 1 << CWORD_BIT_SIZE);
+
+		tmp = period_ns * rate;
+		do_div(tmp, NSEC_PER_SEC);
+		pc = tmp;
+
+		tmp = (duty_ns + 1) * rate;
+		do_div(tmp, NSEC_PER_SEC);
+		dc = tmp;
+
+		/*
+		 * We can be called with separate duty and period updates,
+		 * so do not reject dc == 0 right away
+		 */
+		if (pc == PWM_PERIOD_MIN || (dc < PWM_ON_MIN && duty_ns))
+			return -EINVAL;
+
+		/* We converged on a calculation */
+		if (pc <= PWM_ON_PERIOD_MAX && dc <= PWM_ON_PERIOD_MAX)
+			break;
+
+		/*
+		 * The cword needs to be a power of 2 for the variable
+		 * frequency generator to output a 50% duty cycle variable
+		 * frequency which is used as input clock to the fixed
+		 * frequency generator.
+		 */
+		cword >>= 1;
+
+		/*
+		 * Desired periods are too large, we do not have a divider
+		 * for them
+		 */
+		if (cword < CONST_VAR_F_MIN)
+			return -EINVAL;
+	}
+
+done:
+	/*
+	 * Configure the defined "cword" value to have the variable frequency
+	 * generator output a base frequency for the constant frequency
+	 * generator to derive from.
+	 */
+	spin_lock(&p->lock);
+	brcmstb_pwm_writel(p, cword >> 8, PWM_CWORD_MSB(channel));
+	brcmstb_pwm_writel(p, cword & 0xff, PWM_CWORD_LSB(channel));
+
+	/* Select constant frequency signal output */
+	value = brcmstb_pwm_readl(p, PWM_CTRL2);
+	value |= CTRL2_OUT_SELECT << (channel * CTRL_CHAN_OFFS);
+	brcmstb_pwm_writel(p, value, PWM_CTRL2);
+
+	/* Configure on and period value */
+	brcmstb_pwm_writel(p, pc, PWM_PERIOD(channel));
+	brcmstb_pwm_writel(p, dc, PWM_ON(channel));
+	spin_unlock(&p->lock);
+
+	return 0;
+}
+
+static inline void brcmstb_pwm_enable_set(struct brcmstb_pwm *p,
+					  unsigned int channel, bool enable)
+{
+	unsigned int shift = channel * CTRL_CHAN_OFFS;
+	u32 value;
+
+	spin_lock(&p->lock);
+	value = brcmstb_pwm_readl(p, PWM_CTRL);
+
+	if (enable) {
+		value &= ~(CTRL_OEB << shift);
+		value |= (CTRL_START | CTRL_OPENDRAIN) << shift;
+	} else {
+		value &= ~((CTRL_START | CTRL_OPENDRAIN) << shift);
+		value |= CTRL_OEB << shift;
+	}
+
+	brcmstb_pwm_writel(p, value, PWM_CTRL);
+	spin_unlock(&p->lock);
+}
+
+static int brcmstb_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct brcmstb_pwm *p = to_brcmstb_pwm(chip);
+
+	brcmstb_pwm_enable_set(p, pwm->hwpwm, true);
+
+	return 0;
+}
+
+static void brcmstb_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct brcmstb_pwm *p = to_brcmstb_pwm(chip);
+
+	brcmstb_pwm_enable_set(p, pwm->hwpwm, false);
+}
+
+static const struct pwm_ops brcmstb_pwm_ops = {
+	.config = brcmstb_pwm_config,
+	.enable = brcmstb_pwm_enable,
+	.disable = brcmstb_pwm_disable,
+	.owner = THIS_MODULE,
+};
+
+static const struct of_device_id brcmstb_pwm_of_match[] = {
+	{ .compatible = "brcm,bcm7038-pwm", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, brcmstb_pwm_of_match);
+
+static int brcmstb_pwm_probe(struct platform_device *pdev)
+{
+	struct brcmstb_pwm *p;
+	struct resource *res;
+	int ret;
+
+	p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);
+	if (!p)
+		return -ENOMEM;
+
+	spin_lock_init(&p->lock);
+
+	p->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(p->clk)) {
+		dev_err(&pdev->dev, "failed to obtain clock\n");
+		return PTR_ERR(p->clk);
+	}
+
+	ret = clk_prepare_enable(p->clk);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to enable clock: %d\n", ret);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, p);
+
+	p->chip.dev = &pdev->dev;
+	p->chip.ops = &brcmstb_pwm_ops;
+	p->chip.base = -1;
+	p->chip.npwm = 2;
+	p->chip.can_sleep = true;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	p->base = devm_ioremap_resource(&pdev->dev, res);
+	if (!p->base) {
+		ret = -ENOMEM;
+		goto out_clk;
+	}
+
+	ret = pwmchip_add(&p->chip);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
+		goto out_clk;
+	}
+
+	return 0;
+
+out_clk:
+	clk_disable_unprepare(p->clk);
+	return ret;
+}
+
+static int brcmstb_pwm_remove(struct platform_device *pdev)
+{
+	struct brcmstb_pwm *p = platform_get_drvdata(pdev);
+	int ret;
+
+	ret = pwmchip_remove(&p->chip);
+	clk_disable_unprepare(p->clk);
+
+	return ret;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int brcmstb_pwm_suspend(struct device *dev)
+{
+	struct brcmstb_pwm *p = dev_get_drvdata(dev);
+
+	clk_disable(p->clk);
+
+	return 0;
+}
+
+static int brcmstb_pwm_resume(struct device *dev)
+{
+	struct brcmstb_pwm *p = dev_get_drvdata(dev);
+
+	clk_enable(p->clk);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(brcmstb_pwm_pm_ops, brcmstb_pwm_suspend,
+			 brcmstb_pwm_resume);
+
+static struct platform_driver brcmstb_pwm_driver = {
+	.probe = brcmstb_pwm_probe,
+	.remove = brcmstb_pwm_remove,
+	.driver = {
+		.name = "pwm-brcmstb",
+		.of_match_table = brcmstb_pwm_of_match,
+		.pm = &brcmstb_pwm_pm_ops,
+	},
+};
+module_platform_driver(brcmstb_pwm_driver);
+
+MODULE_AUTHOR("Florian Fainelli <f.fainelli@gmail.com>");
+MODULE_DESCRIPTION("Broadcom STB PWM driver");
+MODULE_ALIAS("platform:pwm-brcmstb");
+MODULE_LICENSE("GPL");