diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-11-11 09:16:10 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-11-11 09:16:10 -0800 |
commit | c8fff3ed321abf11bea7464884b0876c46ff2491 (patch) | |
tree | 0275ed769371ba07451b14c41d4c0760efa1b8e1 /drivers/pwm/pwm-rcar.c | |
parent | baf51c43926ec9aa42ef9d33ca6ee9e3e043aebe (diff) | |
parent | 5dcd7b42f1d06c62b5589441e69cc77c26c8b725 (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-rcar.c')
-rw-r--r-- | drivers/pwm/pwm-rcar.c | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-rcar.c b/drivers/pwm/pwm-rcar.c new file mode 100644 index 000000000000..6e99a63ffa29 --- /dev/null +++ b/drivers/pwm/pwm-rcar.c @@ -0,0 +1,274 @@ +/* + * R-Car PWM Timer driver + * + * Copyright (C) 2015 Renesas Electronics Corporation + * + * This is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + */ + +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/pwm.h> +#include <linux/slab.h> + +#define RCAR_PWM_MAX_DIVISION 24 +#define RCAR_PWM_MAX_CYCLE 1023 + +#define RCAR_PWMCR 0x00 +#define RCAR_PWMCR_CC0_MASK 0x000f0000 +#define RCAR_PWMCR_CC0_SHIFT 16 +#define RCAR_PWMCR_CCMD BIT(15) +#define RCAR_PWMCR_SYNC BIT(11) +#define RCAR_PWMCR_SS0 BIT(4) +#define RCAR_PWMCR_EN0 BIT(0) + +#define RCAR_PWMCNT 0x04 +#define RCAR_PWMCNT_CYC0_MASK 0x03ff0000 +#define RCAR_PWMCNT_CYC0_SHIFT 16 +#define RCAR_PWMCNT_PH0_MASK 0x000003ff +#define RCAR_PWMCNT_PH0_SHIFT 0 + +struct rcar_pwm_chip { + struct pwm_chip chip; + void __iomem *base; + struct clk *clk; +}; + +static inline struct rcar_pwm_chip *to_rcar_pwm_chip(struct pwm_chip *chip) +{ + return container_of(chip, struct rcar_pwm_chip, chip); +} + +static void rcar_pwm_write(struct rcar_pwm_chip *rp, u32 data, + unsigned int offset) +{ + writel(data, rp->base + offset); +} + +static u32 rcar_pwm_read(struct rcar_pwm_chip *rp, unsigned int offset) +{ + return readl(rp->base + offset); +} + +static void rcar_pwm_update(struct rcar_pwm_chip *rp, u32 mask, u32 data, + unsigned int offset) +{ + u32 value; + + value = rcar_pwm_read(rp, offset); + value &= ~mask; + value |= data & mask; + rcar_pwm_write(rp, value, offset); +} + +static int rcar_pwm_get_clock_division(struct rcar_pwm_chip *rp, int period_ns) +{ + unsigned long clk_rate = clk_get_rate(rp->clk); + unsigned long long max; /* max cycle / nanoseconds */ + unsigned int div; + + if (clk_rate == 0) + return -EINVAL; + + for (div = 0; div <= RCAR_PWM_MAX_DIVISION; div++) { + max = (unsigned long long)NSEC_PER_SEC * RCAR_PWM_MAX_CYCLE * + (1 << div); + do_div(max, clk_rate); + if (period_ns < max) + break; + } + + return (div <= RCAR_PWM_MAX_DIVISION) ? div : -ERANGE; +} + +static void rcar_pwm_set_clock_control(struct rcar_pwm_chip *rp, + unsigned int div) +{ + u32 value; + + value = rcar_pwm_read(rp, RCAR_PWMCR); + value &= ~(RCAR_PWMCR_CCMD | RCAR_PWMCR_CC0_MASK); + + if (div & 1) + value |= RCAR_PWMCR_CCMD; + + div >>= 1; + + value |= div << RCAR_PWMCR_CC0_SHIFT; + rcar_pwm_write(rp, value, RCAR_PWMCR); +} + +static int rcar_pwm_set_counter(struct rcar_pwm_chip *rp, int div, int duty_ns, + int period_ns) +{ + unsigned long long one_cycle, tmp; /* 0.01 nanoseconds */ + unsigned long clk_rate = clk_get_rate(rp->clk); + u32 cyc, ph; + + one_cycle = (unsigned long long)NSEC_PER_SEC * 100ULL * (1 << div); + do_div(one_cycle, clk_rate); + + tmp = period_ns * 100ULL; + do_div(tmp, one_cycle); + cyc = (tmp << RCAR_PWMCNT_CYC0_SHIFT) & RCAR_PWMCNT_CYC0_MASK; + + tmp = duty_ns * 100ULL; + do_div(tmp, one_cycle); + ph = tmp & RCAR_PWMCNT_PH0_MASK; + + /* Avoid prohibited setting */ + if (cyc == 0 || ph == 0) + return -EINVAL; + + rcar_pwm_write(rp, cyc | ph, RCAR_PWMCNT); + + return 0; +} + +static int rcar_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct rcar_pwm_chip *rp = to_rcar_pwm_chip(chip); + + return clk_prepare_enable(rp->clk); +} + +static void rcar_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct rcar_pwm_chip *rp = to_rcar_pwm_chip(chip); + + clk_disable_unprepare(rp->clk); +} + +static int rcar_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, + int duty_ns, int period_ns) +{ + struct rcar_pwm_chip *rp = to_rcar_pwm_chip(chip); + int div, ret; + + div = rcar_pwm_get_clock_division(rp, period_ns); + if (div < 0) + return div; + + /* Let the core driver set pwm->period if disabled and duty_ns == 0 */ + if (!test_bit(PWMF_ENABLED, &pwm->flags) && !duty_ns) + return 0; + + rcar_pwm_update(rp, RCAR_PWMCR_SYNC, RCAR_PWMCR_SYNC, RCAR_PWMCR); + + ret = rcar_pwm_set_counter(rp, div, duty_ns, period_ns); + if (!ret) + rcar_pwm_set_clock_control(rp, div); + + /* The SYNC should be set to 0 even if rcar_pwm_set_counter failed */ + rcar_pwm_update(rp, RCAR_PWMCR_SYNC, 0, RCAR_PWMCR); + + return ret; +} + +static int rcar_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct rcar_pwm_chip *rp = to_rcar_pwm_chip(chip); + u32 value; + + /* Don't enable the PWM device if CYC0 or PH0 is 0 */ + value = rcar_pwm_read(rp, RCAR_PWMCNT); + if ((value & RCAR_PWMCNT_CYC0_MASK) == 0 || + (value & RCAR_PWMCNT_PH0_MASK) == 0) + return -EINVAL; + + rcar_pwm_update(rp, RCAR_PWMCR_EN0, RCAR_PWMCR_EN0, RCAR_PWMCR); + + return 0; +} + +static void rcar_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct rcar_pwm_chip *rp = to_rcar_pwm_chip(chip); + + rcar_pwm_update(rp, RCAR_PWMCR_EN0, 0, RCAR_PWMCR); +} + +static const struct pwm_ops rcar_pwm_ops = { + .request = rcar_pwm_request, + .free = rcar_pwm_free, + .config = rcar_pwm_config, + .enable = rcar_pwm_enable, + .disable = rcar_pwm_disable, + .owner = THIS_MODULE, +}; + +static int rcar_pwm_probe(struct platform_device *pdev) +{ + struct rcar_pwm_chip *rcar_pwm; + struct resource *res; + int ret; + + rcar_pwm = devm_kzalloc(&pdev->dev, sizeof(*rcar_pwm), GFP_KERNEL); + if (rcar_pwm == NULL) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + rcar_pwm->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(rcar_pwm->base)) + return PTR_ERR(rcar_pwm->base); + + rcar_pwm->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(rcar_pwm->clk)) { + dev_err(&pdev->dev, "cannot get clock\n"); + return PTR_ERR(rcar_pwm->clk); + } + + platform_set_drvdata(pdev, rcar_pwm); + + rcar_pwm->chip.dev = &pdev->dev; + rcar_pwm->chip.ops = &rcar_pwm_ops; + rcar_pwm->chip.base = -1; + rcar_pwm->chip.npwm = 1; + + ret = pwmchip_add(&rcar_pwm->chip); + if (ret < 0) { + dev_err(&pdev->dev, "failed to register PWM chip: %d\n", ret); + return ret; + } + + pm_runtime_enable(&pdev->dev); + + return 0; +} + +static int rcar_pwm_remove(struct platform_device *pdev) +{ + struct rcar_pwm_chip *rcar_pwm = platform_get_drvdata(pdev); + + pm_runtime_disable(&pdev->dev); + + return pwmchip_remove(&rcar_pwm->chip); +} + +static const struct of_device_id rcar_pwm_of_table[] = { + { .compatible = "renesas,pwm-rcar", }, + { }, +}; +MODULE_DEVICE_TABLE(of, rcar_pwm_of_table); + +static struct platform_driver rcar_pwm_driver = { + .probe = rcar_pwm_probe, + .remove = rcar_pwm_remove, + .driver = { + .name = "pwm-rcar", + .of_match_table = of_match_ptr(rcar_pwm_of_table), + } +}; +module_platform_driver(rcar_pwm_driver); + +MODULE_AUTHOR("Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>"); +MODULE_DESCRIPTION("Renesas PWM Timer Driver"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:pwm-rcar"); |