diff options
author | 2016-04-11 10:41:07 +0300 | |
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committer | 2016-04-13 08:17:18 +0300 | |
commit | e09b41010ba33a20a87472ee821fa407a5b8da36 (patch) | |
tree | d10dc367189862e7ca5c592f033dc3726e1df4e3 /kernel/drivers/pwm/pwm-crc.c | |
parent | f93b97fd65072de626c074dbe099a1fff05ce060 (diff) |
These changes are the raw update to linux-4.4.6-rt14. Kernel sources
are taken from kernel.org, and rt patch from the rt wiki download page.
During the rebasing, the following patch collided:
Force tick interrupt and get rid of softirq magic(I70131fb85).
Collisions have been removed because its logic was found on the
source already.
Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769
Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>
Diffstat (limited to 'kernel/drivers/pwm/pwm-crc.c')
-rw-r--r-- | kernel/drivers/pwm/pwm-crc.c | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/kernel/drivers/pwm/pwm-crc.c b/kernel/drivers/pwm/pwm-crc.c new file mode 100644 index 000000000..7101c7020 --- /dev/null +++ b/kernel/drivers/pwm/pwm-crc.c @@ -0,0 +1,143 @@ +/* + * Copyright (C) 2015 Intel Corporation. All rights reserved. + * + * 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. + * + * 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. + * + * Author: Shobhit Kumar <shobhit.kumar@intel.com> + */ + +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/mfd/intel_soc_pmic.h> +#include <linux/pwm.h> + +#define PWM0_CLK_DIV 0x4B +#define PWM_OUTPUT_ENABLE BIT(7) +#define PWM_DIV_CLK_0 0x00 /* DIVIDECLK = BASECLK */ +#define PWM_DIV_CLK_100 0x63 /* DIVIDECLK = BASECLK/100 */ +#define PWM_DIV_CLK_128 0x7F /* DIVIDECLK = BASECLK/128 */ + +#define PWM0_DUTY_CYCLE 0x4E +#define BACKLIGHT_EN 0x51 + +#define PWM_MAX_LEVEL 0xFF + +#define PWM_BASE_CLK 6000000 /* 6 MHz */ +#define PWM_MAX_PERIOD_NS 21333 /* 46.875KHz */ + +/** + * struct crystalcove_pwm - Crystal Cove PWM controller + * @chip: the abstract pwm_chip structure. + * @regmap: the regmap from the parent device. + */ +struct crystalcove_pwm { + struct pwm_chip chip; + struct regmap *regmap; +}; + +static inline struct crystalcove_pwm *to_crc_pwm(struct pwm_chip *pc) +{ + return container_of(pc, struct crystalcove_pwm, chip); +} + +static int crc_pwm_enable(struct pwm_chip *c, struct pwm_device *pwm) +{ + struct crystalcove_pwm *crc_pwm = to_crc_pwm(c); + + regmap_write(crc_pwm->regmap, BACKLIGHT_EN, 1); + + return 0; +} + +static void crc_pwm_disable(struct pwm_chip *c, struct pwm_device *pwm) +{ + struct crystalcove_pwm *crc_pwm = to_crc_pwm(c); + + regmap_write(crc_pwm->regmap, BACKLIGHT_EN, 0); +} + +static int crc_pwm_config(struct pwm_chip *c, struct pwm_device *pwm, + int duty_ns, int period_ns) +{ + struct crystalcove_pwm *crc_pwm = to_crc_pwm(c); + struct device *dev = crc_pwm->chip.dev; + int level; + + if (period_ns > PWM_MAX_PERIOD_NS) { + dev_err(dev, "un-supported period_ns\n"); + return -EINVAL; + } + + if (pwm->period != period_ns) { + int clk_div; + + /* changing the clk divisor, need to disable fisrt */ + crc_pwm_disable(c, pwm); + clk_div = PWM_BASE_CLK * period_ns / NSEC_PER_SEC; + + regmap_write(crc_pwm->regmap, PWM0_CLK_DIV, + clk_div | PWM_OUTPUT_ENABLE); + + /* enable back */ + crc_pwm_enable(c, pwm); + } + + /* change the pwm duty cycle */ + level = duty_ns * PWM_MAX_LEVEL / period_ns; + regmap_write(crc_pwm->regmap, PWM0_DUTY_CYCLE, level); + + return 0; +} + +static const struct pwm_ops crc_pwm_ops = { + .config = crc_pwm_config, + .enable = crc_pwm_enable, + .disable = crc_pwm_disable, +}; + +static int crystalcove_pwm_probe(struct platform_device *pdev) +{ + struct crystalcove_pwm *pwm; + struct device *dev = pdev->dev.parent; + struct intel_soc_pmic *pmic = dev_get_drvdata(dev); + + pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL); + if (!pwm) + return -ENOMEM; + + pwm->chip.dev = &pdev->dev; + pwm->chip.ops = &crc_pwm_ops; + pwm->chip.base = -1; + pwm->chip.npwm = 1; + + /* get the PMIC regmap */ + pwm->regmap = pmic->regmap; + + platform_set_drvdata(pdev, pwm); + + return pwmchip_add(&pwm->chip); +} + +static int crystalcove_pwm_remove(struct platform_device *pdev) +{ + struct crystalcove_pwm *pwm = platform_get_drvdata(pdev); + + return pwmchip_remove(&pwm->chip); +} + +static struct platform_driver crystalcove_pwm_driver = { + .probe = crystalcove_pwm_probe, + .remove = crystalcove_pwm_remove, + .driver = { + .name = "crystal_cove_pwm", + }, +}; + +builtin_platform_driver(crystalcove_pwm_driver); |