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authorLinus Torvalds <torvalds@linux-foundation.org>2015-11-11 09:16:10 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2015-11-11 09:16:10 -0800
commitc8fff3ed321abf11bea7464884b0876c46ff2491 (patch)
tree0275ed769371ba07451b14c41d4c0760efa1b8e1 /drivers/pwm/pwm-berlin.c
parentbaf51c43926ec9aa42ef9d33ca6ee9e3e043aebe (diff)
parent5dcd7b42f1d06c62b5589441e69cc77c26c8b725 (diff)
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 ...
Diffstat (limited to 'drivers/pwm/pwm-berlin.c')
-rw-r--r--drivers/pwm/pwm-berlin.c219
1 files changed, 219 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-berlin.c b/drivers/pwm/pwm-berlin.c
new file mode 100644
index 000000000000..65108129d505
--- /dev/null
+++ b/drivers/pwm/pwm-berlin.c
@@ -0,0 +1,219 @@
+/*
+ * Marvell Berlin PWM driver
+ *
+ * Copyright (C) 2015 Marvell Technology Group Ltd.
+ *
+ * Author: Antoine Tenart <antoine.tenart@free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+
+#define BERLIN_PWM_EN 0x0
+#define BERLIN_PWM_ENABLE BIT(0)
+#define BERLIN_PWM_CONTROL 0x4
+#define BERLIN_PWM_PRESCALE_MASK 0x7
+#define BERLIN_PWM_PRESCALE_MAX 4096
+#define BERLIN_PWM_INVERT_POLARITY BIT(3)
+#define BERLIN_PWM_DUTY 0x8
+#define BERLIN_PWM_TCNT 0xc
+#define BERLIN_PWM_MAX_TCNT 65535
+
+struct berlin_pwm_chip {
+ struct pwm_chip chip;
+ struct clk *clk;
+ void __iomem *base;
+};
+
+static inline struct berlin_pwm_chip *to_berlin_pwm_chip(struct pwm_chip *chip)
+{
+ return container_of(chip, struct berlin_pwm_chip, chip);
+}
+
+static const u32 prescaler_table[] = {
+ 1, 4, 8, 16, 64, 256, 1024, 4096
+};
+
+static inline u32 berlin_pwm_readl(struct berlin_pwm_chip *chip,
+ unsigned int channel, unsigned long offset)
+{
+ return readl_relaxed(chip->base + channel * 0x10 + offset);
+}
+
+static inline void berlin_pwm_writel(struct berlin_pwm_chip *chip,
+ unsigned int channel, u32 value,
+ unsigned long offset)
+{
+ writel_relaxed(value, chip->base + channel * 0x10 + offset);
+}
+
+static int berlin_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm_dev,
+ int duty_ns, int period_ns)
+{
+ struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
+ unsigned int prescale;
+ u32 value, duty, period;
+ u64 cycles, tmp;
+
+ cycles = clk_get_rate(pwm->clk);
+ cycles *= period_ns;
+ do_div(cycles, NSEC_PER_SEC);
+
+ for (prescale = 0; prescale < ARRAY_SIZE(prescaler_table); prescale++) {
+ tmp = cycles;
+ do_div(tmp, prescaler_table[prescale]);
+
+ if (tmp <= BERLIN_PWM_MAX_TCNT)
+ break;
+ }
+
+ if (tmp > BERLIN_PWM_MAX_TCNT)
+ return -ERANGE;
+
+ period = tmp;
+ cycles = tmp * duty_ns;
+ do_div(cycles, period_ns);
+ duty = cycles;
+
+ value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL);
+ value &= ~BERLIN_PWM_PRESCALE_MASK;
+ value |= prescale;
+ berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_CONTROL);
+
+ berlin_pwm_writel(pwm, pwm_dev->hwpwm, duty, BERLIN_PWM_DUTY);
+ berlin_pwm_writel(pwm, pwm_dev->hwpwm, period, BERLIN_PWM_TCNT);
+
+ return 0;
+}
+
+static int berlin_pwm_set_polarity(struct pwm_chip *chip,
+ struct pwm_device *pwm_dev,
+ enum pwm_polarity polarity)
+{
+ struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
+ u32 value;
+
+ value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL);
+
+ if (polarity == PWM_POLARITY_NORMAL)
+ value &= ~BERLIN_PWM_INVERT_POLARITY;
+ else
+ value |= BERLIN_PWM_INVERT_POLARITY;
+
+ berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_CONTROL);
+
+ return 0;
+}
+
+static int berlin_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm_dev)
+{
+ struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
+ u32 value;
+
+ value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_EN);
+ value |= BERLIN_PWM_ENABLE;
+ berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_EN);
+
+ return 0;
+}
+
+static void berlin_pwm_disable(struct pwm_chip *chip,
+ struct pwm_device *pwm_dev)
+{
+ struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
+ u32 value;
+
+ value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_EN);
+ value &= ~BERLIN_PWM_ENABLE;
+ berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_EN);
+}
+
+static const struct pwm_ops berlin_pwm_ops = {
+ .config = berlin_pwm_config,
+ .set_polarity = berlin_pwm_set_polarity,
+ .enable = berlin_pwm_enable,
+ .disable = berlin_pwm_disable,
+ .owner = THIS_MODULE,
+};
+
+static const struct of_device_id berlin_pwm_match[] = {
+ { .compatible = "marvell,berlin-pwm" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, berlin_pwm_match);
+
+static int berlin_pwm_probe(struct platform_device *pdev)
+{
+ struct berlin_pwm_chip *pwm;
+ struct resource *res;
+ int ret;
+
+ pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
+ if (!pwm)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ pwm->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(pwm->base))
+ return PTR_ERR(pwm->base);
+
+ pwm->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(pwm->clk))
+ return PTR_ERR(pwm->clk);
+
+ ret = clk_prepare_enable(pwm->clk);
+ if (ret)
+ return ret;
+
+ pwm->chip.dev = &pdev->dev;
+ pwm->chip.ops = &berlin_pwm_ops;
+ pwm->chip.base = -1;
+ pwm->chip.npwm = 4;
+ pwm->chip.can_sleep = true;
+ pwm->chip.of_xlate = of_pwm_xlate_with_flags;
+ pwm->chip.of_pwm_n_cells = 3;
+
+ ret = pwmchip_add(&pwm->chip);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
+ clk_disable_unprepare(pwm->clk);
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, pwm);
+
+ return 0;
+}
+
+static int berlin_pwm_remove(struct platform_device *pdev)
+{
+ struct berlin_pwm_chip *pwm = platform_get_drvdata(pdev);
+ int ret;
+
+ ret = pwmchip_remove(&pwm->chip);
+ clk_disable_unprepare(pwm->clk);
+
+ return ret;
+}
+
+static struct platform_driver berlin_pwm_driver = {
+ .probe = berlin_pwm_probe,
+ .remove = berlin_pwm_remove,
+ .driver = {
+ .name = "berlin-pwm",
+ .of_match_table = berlin_pwm_match,
+ },
+};
+module_platform_driver(berlin_pwm_driver);
+
+MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>");
+MODULE_DESCRIPTION("Marvell Berlin PWM driver");
+MODULE_LICENSE("GPL v2");