pwm-ab8500.c revision 6173f8f4ed9c2bd4184908e35f46755a0d14b0f2
1f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy/* 2f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * Copyright (C) ST-Ericsson SA 2010 3f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * 4f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * Author: Arun R Murthy <arun.murthy@stericsson.com> 5f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * License terms: GNU General Public License (GPL) version 2 6f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy */ 7f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy#include <linux/err.h> 8f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy#include <linux/platform_device.h> 9f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy#include <linux/slab.h> 10f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy#include <linux/pwm.h> 11f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy#include <linux/mfd/abx500.h> 12ee66e653ca7425bc8ffca4e00f19a8057cd14e4dLinus Walleij#include <linux/mfd/abx500/ab8500.h> 13eb12a679b242c03b9eaa38a67cae9fa3e17ddea6Paul Gortmaker#include <linux/module.h> 14f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 15f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy/* 16f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * PWM Out generators 17f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * Bank: 0x10 18f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy */ 19f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy#define AB8500_PWM_OUT_CTRL1_REG 0x60 20f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy#define AB8500_PWM_OUT_CTRL2_REG 0x61 21f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy#define AB8500_PWM_OUT_CTRL7_REG 0x66 22f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 23f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy/* backlight driver constants */ 24f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy#define ENABLE_PWM 1 25f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy#define DISABLE_PWM 0 26f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 276173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Redingstruct ab8500_pwm_chip { 286173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding struct pwm_chip chip; 29f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy}; 30f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 316173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Redingstatic int ab8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, 326173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding int duty_ns, int period_ns) 33f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy{ 34f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy int ret = 0; 35f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy unsigned int higher_val, lower_val; 36f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy u8 reg; 37f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 38f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy /* 39f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * get the first 8 bits that are be written to 40f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * AB8500_PWM_OUT_CTRL1_REG[0:7] 41f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy */ 42f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy lower_val = duty_ns & 0x00FF; 43f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy /* 44f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * get bits [9:10] that are to be written to 45f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * AB8500_PWM_OUT_CTRL2_REG[0:1] 46f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy */ 47f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy higher_val = ((duty_ns & 0x0300) >> 8); 48f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 496173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding reg = AB8500_PWM_OUT_CTRL1_REG + ((chip->base - 1) * 2); 50f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 516173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC, 52f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy reg, (u8)lower_val); 53f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy if (ret < 0) 54f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy return ret; 556173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC, 56f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy (reg + 1), (u8)higher_val); 57f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 58f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy return ret; 59f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy} 60f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 616173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Redingstatic int ab8500_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) 62f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy{ 63f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy int ret; 64f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 656173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding ret = abx500_mask_and_set_register_interruptible(chip->dev, 66f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG, 676173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding 1 << (chip->base - 1), ENABLE_PWM); 68f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy if (ret < 0) 696173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n", 70f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy pwm->label, ret); 71f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy return ret; 72f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy} 73f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 746173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Redingstatic void ab8500_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) 75f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy{ 76f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy int ret; 77f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 786173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding ret = abx500_mask_and_set_register_interruptible(chip->dev, 79f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG, 806173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding 1 << (chip->base - 1), DISABLE_PWM); 81f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy if (ret < 0) 826173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n", 83f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy pwm->label, ret); 84f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy return; 85f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy} 86f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 876173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Redingstatic const struct pwm_ops ab8500_pwm_ops = { 886173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding .config = ab8500_pwm_config, 896173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding .enable = ab8500_pwm_enable, 906173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding .disable = ab8500_pwm_disable, 916173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding}; 92f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 93f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthystatic int __devinit ab8500_pwm_probe(struct platform_device *pdev) 94f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy{ 956173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding struct ab8500_pwm_chip *ab8500; 966173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding int err; 976173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding 98f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy /* 99f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * Nothing to be done in probe, this is required to get the 100f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * device which is required for ab8500 read and write 101f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy */ 1026173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding ab8500 = kzalloc(sizeof(*ab8500), GFP_KERNEL); 1036173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding if (ab8500 == NULL) { 104f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy dev_err(&pdev->dev, "failed to allocate memory\n"); 105f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy return -ENOMEM; 106f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy } 1076173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding 1086173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding ab8500->chip.dev = &pdev->dev; 1096173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding ab8500->chip.ops = &ab8500_pwm_ops; 1106173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding ab8500->chip.base = pdev->id; 1116173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding ab8500->chip.npwm = 1; 1126173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding 1136173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding err = pwmchip_add(&ab8500->chip); 1146173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding if (err < 0) { 1156173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding kfree(ab8500); 1166173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding return err; 1176173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding } 1186173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding 1196173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding dev_dbg(&pdev->dev, "pwm probe successful\n"); 1206173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding platform_set_drvdata(pdev, ab8500); 1216173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding 122f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy return 0; 123f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy} 124f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 125f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthystatic int __devexit ab8500_pwm_remove(struct platform_device *pdev) 126f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy{ 1276173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding struct ab8500_pwm_chip *ab8500 = platform_get_drvdata(pdev); 1286173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding int err; 1296173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding 1306173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding err = pwmchip_remove(&ab8500->chip); 1316173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding if (err < 0) 1326173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding return err; 1336173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding 134f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy dev_dbg(&pdev->dev, "pwm driver removed\n"); 1356173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding kfree(ab8500); 1366173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding 137f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy return 0; 138f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy} 139f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 140f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthystatic struct platform_driver ab8500_pwm_driver = { 141f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy .driver = { 142f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy .name = "ab8500-pwm", 143f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy .owner = THIS_MODULE, 144f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy }, 145f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy .probe = ab8500_pwm_probe, 146f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy .remove = __devexit_p(ab8500_pwm_remove), 147f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy}; 1486173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Redingmodule_platform_driver(ab8500_pwm_driver); 149f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 150f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun MurthyMODULE_AUTHOR("Arun MURTHY <arun.murthy@stericsson.com>"); 151f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun MurthyMODULE_DESCRIPTION("AB8500 Pulse Width Modulation Driver"); 15237b7bf67c36d3a2b426c0cb2787d948949574103Axel LinMODULE_ALIAS("platform:ab8500-pwm"); 153f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun MurthyMODULE_LICENSE("GPL v2"); 154