pwm-ab8500.c revision a2fc1db61a651cd9b9dce2622562eadcc9e1e15c
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) 69622fc5d4452a20aab7b8f5107c2931c5610e5753Axel Lin dev_err(chip->dev, "%s: Failed to enable 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, 91fa0abee9b89e3a0bab207823bd16372de53c3896Axel Lin .owner = THIS_MODULE, 926173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding}; 93f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 943e9fe83d278cce6974f0a4d1870c0ff4a0b74ba5Bill Pembertonstatic int ab8500_pwm_probe(struct platform_device *pdev) 95f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy{ 966173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding struct ab8500_pwm_chip *ab8500; 976173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding int err; 986173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding 99f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy /* 100f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * Nothing to be done in probe, this is required to get the 101f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * device which is required for ab8500 read and write 102f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy */ 103482467ad97b633b28f57c347440d97c108dc4bfbJingoo Han ab8500 = devm_kzalloc(&pdev->dev, sizeof(*ab8500), GFP_KERNEL); 104a2fc1db61a651cd9b9dce2622562eadcc9e1e15cJingoo Han if (ab8500 == NULL) 105f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy return -ENOMEM; 1066173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding 1076173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding ab8500->chip.dev = &pdev->dev; 1086173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding ab8500->chip.ops = &ab8500_pwm_ops; 1096173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding ab8500->chip.base = pdev->id; 1106173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding ab8500->chip.npwm = 1; 1116173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding 1126173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding err = pwmchip_add(&ab8500->chip); 113482467ad97b633b28f57c347440d97c108dc4bfbJingoo Han if (err < 0) 1146173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding return err; 1156173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding 1166173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding dev_dbg(&pdev->dev, "pwm probe successful\n"); 1176173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding platform_set_drvdata(pdev, ab8500); 1186173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding 119f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy return 0; 120f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy} 121f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 12277f37917a6f2bd8635b553178bb34bdd80f08e40Bill Pembertonstatic int ab8500_pwm_remove(struct platform_device *pdev) 123f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy{ 1246173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding struct ab8500_pwm_chip *ab8500 = platform_get_drvdata(pdev); 1256173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding int err; 1266173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding 1276173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding err = pwmchip_remove(&ab8500->chip); 1286173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding if (err < 0) 1296173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding return err; 1306173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding 131f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy dev_dbg(&pdev->dev, "pwm driver removed\n"); 1326173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Reding 133f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy return 0; 134f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy} 135f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 136f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthystatic struct platform_driver ab8500_pwm_driver = { 137f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy .driver = { 138f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy .name = "ab8500-pwm", 139f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy .owner = THIS_MODULE, 140f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy }, 141f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy .probe = ab8500_pwm_probe, 142fd1091125a1d11fcc635749d0d3dec36904a7a48Bill Pemberton .remove = ab8500_pwm_remove, 143f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy}; 1446173f8f4ed9c2bd4184908e35f46755a0d14b0f2Thierry Redingmodule_platform_driver(ab8500_pwm_driver); 145f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 146f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun MurthyMODULE_AUTHOR("Arun MURTHY <arun.murthy@stericsson.com>"); 147f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun MurthyMODULE_DESCRIPTION("AB8500 Pulse Width Modulation Driver"); 14837b7bf67c36d3a2b426c0cb2787d948949574103Axel LinMODULE_ALIAS("platform:ab8500-pwm"); 149f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun MurthyMODULE_LICENSE("GPL v2"); 150