drivers/leds/leds-mt6323.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * LED driver for Mediatek MT6323 PMIC
0004  *
0005  * Copyright (C) 2017 Sean Wang <sean.wang@mediatek.com>
0006  */
0007 #include <linux/kernel.h>
0008 #include <linux/leds.h>
0009 #include <linux/mfd/mt6323/registers.h>
0010 #include <linux/mfd/mt6397/core.h>
0011 #include <linux/module.h>
0012 #include <linux/of.h>
0013 #include <linux/platform_device.h>
0014 #include <linux/regmap.h>
0015
0016 /*
0017  * Register field for MT6323_TOP_CKPDN0 to enable
0018  * 32K clock common for LED device.
0019  */
0020 #define MT6323_RG_DRV_32K_CK_PDN    BIT(11)
0021 #define MT6323_RG_DRV_32K_CK_PDN_MASK   BIT(11)
0022
0023 /*
0024  * Register field for MT6323_TOP_CKPDN2 to enable
0025  * individual clock for LED device.
0026  */
0027 #define MT6323_RG_ISINK_CK_PDN(i)   BIT(i)
0028 #define MT6323_RG_ISINK_CK_PDN_MASK(i)  BIT(i)
0029
0030 /*
0031  * Register field for MT6323_TOP_CKCON1 to select
0032  * clock source.
0033  */
0034 #define MT6323_RG_ISINK_CK_SEL_MASK(i)  (BIT(10) << (i))
0035
0036 /*
0037  * Register for MT6323_ISINK_CON0 to setup the
0038  * duty cycle of the blink.
0039  */
0040 #define MT6323_ISINK_CON0(i)        (MT6323_ISINK0_CON0 + 0x8 * (i))
0041 #define MT6323_ISINK_DIM_DUTY_MASK  (0x1f << 8)
0042 #define MT6323_ISINK_DIM_DUTY(i)    (((i) << 8) & \
0043                     MT6323_ISINK_DIM_DUTY_MASK)
0044
0045 /* Register to setup the period of the blink. */
0046 #define MT6323_ISINK_CON1(i)        (MT6323_ISINK0_CON1 + 0x8 * (i))
0047 #define MT6323_ISINK_DIM_FSEL_MASK  (0xffff)
0048 #define MT6323_ISINK_DIM_FSEL(i)    ((i) & MT6323_ISINK_DIM_FSEL_MASK)
0049
0050 /* Register to control the brightness. */
0051 #define MT6323_ISINK_CON2(i)        (MT6323_ISINK0_CON2 + 0x8 * (i))
0052 #define MT6323_ISINK_CH_STEP_SHIFT  12
0053 #define MT6323_ISINK_CH_STEP_MASK   (0x7 << 12)
0054 #define MT6323_ISINK_CH_STEP(i)     (((i) << 12) & \
0055                     MT6323_ISINK_CH_STEP_MASK)
0056 #define MT6323_ISINK_SFSTR0_TC_MASK (0x3 << 1)
0057 #define MT6323_ISINK_SFSTR0_TC(i)   (((i) << 1) & \
0058                     MT6323_ISINK_SFSTR0_TC_MASK)
0059 #define MT6323_ISINK_SFSTR0_EN_MASK BIT(0)
0060 #define MT6323_ISINK_SFSTR0_EN      BIT(0)
0061
0062 /* Register to LED channel enablement. */
0063 #define MT6323_ISINK_CH_EN_MASK(i)  BIT(i)
0064 #define MT6323_ISINK_CH_EN(i)       BIT(i)
0065
0066 #define MT6323_MAX_PERIOD       10000
0067 #define MT6323_MAX_LEDS         4
0068 #define MT6323_MAX_BRIGHTNESS       6
0069 #define MT6323_UNIT_DUTY        3125
0070 #define MT6323_CAL_HW_DUTY(o, p)    DIV_ROUND_CLOSEST((o) * 100000ul,\
0071                     (p) * MT6323_UNIT_DUTY)
0072
0073 struct mt6323_leds;
0074
0075 /**
0076  * struct mt6323_led - state container for the LED device
0077  * @id:         the identifier in MT6323 LED device
0078  * @parent:     the pointer to MT6323 LED controller
0079  * @cdev:       LED class device for this LED device
0080  * @current_brightness: current state of the LED device
0081  */
0082 struct mt6323_led {
0083     int         id;
0084     struct mt6323_leds  *parent;
0085     struct led_classdev cdev;
0086     enum led_brightness current_brightness;
0087 };
0088
0089 /**
0090  * struct mt6323_leds - state container for holding LED controller
0091  *          of the driver
0092  * @dev:        the device pointer
0093  * @hw:         the underlying hardware providing shared
0094  *          bus for the register operations
0095  * @lock:       the lock among process context
0096  * @led:        the array that contains the state of individual
0097  *          LED device
0098  */
0099 struct mt6323_leds {
0100     struct device       *dev;
0101     struct mt6397_chip  *hw;
0102     /* protect among process context */
0103     struct mutex        lock;
0104     struct mt6323_led   *led[MT6323_MAX_LEDS];
0105 };
0106
0107 static int mt6323_led_hw_brightness(struct led_classdev *cdev,
0108                     enum led_brightness brightness)
0109 {
0110     struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
0111     struct mt6323_leds *leds = led->parent;
0112     struct regmap *regmap = leds->hw->regmap;
0113     u32 con2_mask = 0, con2_val = 0;
0114     int ret;
0115
0116     /*
0117      * Setup current output for the corresponding
0118      * brightness level.
0119      */
0120     con2_mask |= MT6323_ISINK_CH_STEP_MASK |
0121              MT6323_ISINK_SFSTR0_TC_MASK |
0122              MT6323_ISINK_SFSTR0_EN_MASK;
0123     con2_val |=  MT6323_ISINK_CH_STEP(brightness - 1) |
0124              MT6323_ISINK_SFSTR0_TC(2) |
0125              MT6323_ISINK_SFSTR0_EN;
0126
0127     ret = regmap_update_bits(regmap, MT6323_ISINK_CON2(led->id),
0128                  con2_mask, con2_val);
0129     return ret;
0130 }
0131
0132 static int mt6323_led_hw_off(struct led_classdev *cdev)
0133 {
0134     struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
0135     struct mt6323_leds *leds = led->parent;
0136     struct regmap *regmap = leds->hw->regmap;
0137     unsigned int status;
0138     int ret;
0139
0140     status = MT6323_ISINK_CH_EN(led->id);
0141     ret = regmap_update_bits(regmap, MT6323_ISINK_EN_CTRL,
0142                  MT6323_ISINK_CH_EN_MASK(led->id), ~status);
0143     if (ret < 0)
0144         return ret;
0145
0146     usleep_range(100, 300);
0147     ret = regmap_update_bits(regmap, MT6323_TOP_CKPDN2,
0148                  MT6323_RG_ISINK_CK_PDN_MASK(led->id),
0149                  MT6323_RG_ISINK_CK_PDN(led->id));
0150     if (ret < 0)
0151         return ret;
0152
0153     return 0;
0154 }
0155
0156 static enum led_brightness
0157 mt6323_get_led_hw_brightness(struct led_classdev *cdev)
0158 {
0159     struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
0160     struct mt6323_leds *leds = led->parent;
0161     struct regmap *regmap = leds->hw->regmap;
0162     unsigned int status;
0163     int ret;
0164
0165     ret = regmap_read(regmap, MT6323_TOP_CKPDN2, &status);
0166     if (ret < 0)
0167         return ret;
0168
0169     if (status & MT6323_RG_ISINK_CK_PDN_MASK(led->id))
0170         return 0;
0171
0172     ret = regmap_read(regmap, MT6323_ISINK_EN_CTRL, &status);
0173     if (ret < 0)
0174         return ret;
0175
0176     if (!(status & MT6323_ISINK_CH_EN(led->id)))
0177         return 0;
0178
0179     ret = regmap_read(regmap, MT6323_ISINK_CON2(led->id), &status);
0180     if (ret < 0)
0181         return ret;
0182
0183     return  ((status & MT6323_ISINK_CH_STEP_MASK)
0184           >> MT6323_ISINK_CH_STEP_SHIFT) + 1;
0185 }
0186
0187 static int mt6323_led_hw_on(struct led_classdev *cdev,
0188                 enum led_brightness brightness)
0189 {
0190     struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
0191     struct mt6323_leds *leds = led->parent;
0192     struct regmap *regmap = leds->hw->regmap;
0193     unsigned int status;
0194     int ret;
0195
0196     /*
0197      * Setup required clock source, enable the corresponding
0198      * clock and channel and let work with continuous blink as
0199      * the default.
0200      */
0201     ret = regmap_update_bits(regmap, MT6323_TOP_CKCON1,
0202                  MT6323_RG_ISINK_CK_SEL_MASK(led->id), 0);
0203     if (ret < 0)
0204         return ret;
0205
0206     status = MT6323_RG_ISINK_CK_PDN(led->id);
0207     ret = regmap_update_bits(regmap, MT6323_TOP_CKPDN2,
0208                  MT6323_RG_ISINK_CK_PDN_MASK(led->id),
0209                  ~status);
0210     if (ret < 0)
0211         return ret;
0212
0213     usleep_range(100, 300);
0214
0215     ret = regmap_update_bits(regmap, MT6323_ISINK_EN_CTRL,
0216                  MT6323_ISINK_CH_EN_MASK(led->id),
0217                  MT6323_ISINK_CH_EN(led->id));
0218     if (ret < 0)
0219         return ret;
0220
0221     ret = mt6323_led_hw_brightness(cdev, brightness);
0222     if (ret < 0)
0223         return ret;
0224
0225     ret = regmap_update_bits(regmap, MT6323_ISINK_CON0(led->id),
0226                  MT6323_ISINK_DIM_DUTY_MASK,
0227                  MT6323_ISINK_DIM_DUTY(31));
0228     if (ret < 0)
0229         return ret;
0230
0231     ret = regmap_update_bits(regmap, MT6323_ISINK_CON1(led->id),
0232                  MT6323_ISINK_DIM_FSEL_MASK,
0233                  MT6323_ISINK_DIM_FSEL(1000));
0234     if (ret < 0)
0235         return ret;
0236
0237     return 0;
0238 }
0239
0240 static int mt6323_led_set_blink(struct led_classdev *cdev,
0241                 unsigned long *delay_on,
0242                 unsigned long *delay_off)
0243 {
0244     struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
0245     struct mt6323_leds *leds = led->parent;
0246     struct regmap *regmap = leds->hw->regmap;
0247     unsigned long period;
0248     u8 duty_hw;
0249     int ret;
0250
0251     /*
0252      * LED subsystem requires a default user
0253      * friendly blink pattern for the LED so using
0254      * 1Hz duty cycle 50% here if without specific
0255      * value delay_on and delay off being assigned.
0256      */
0257     if (!*delay_on && !*delay_off) {
0258         *delay_on = 500;
0259         *delay_off = 500;
0260     }
0261
0262     /*
0263      * Units are in ms, if over the hardware able
0264      * to support, fallback into software blink
0265      */
0266     period = *delay_on + *delay_off;
0267
0268     if (period > MT6323_MAX_PERIOD)
0269         return -EINVAL;
0270
0271     /*
0272      * Calculate duty_hw based on the percentage of period during
0273      * which the led is ON.
0274      */
0275     duty_hw = MT6323_CAL_HW_DUTY(*delay_on, period);
0276
0277     /* hardware doesn't support zero duty cycle. */
0278     if (!duty_hw)
0279         return -EINVAL;
0280
0281     mutex_lock(&leds->lock);
0282     /*
0283      * Set max_brightness as the software blink behavior
0284      * when no blink brightness.
0285      */
0286     if (!led->current_brightness) {
0287         ret = mt6323_led_hw_on(cdev, cdev->max_brightness);
0288         if (ret < 0)
0289             goto out;
0290         led->current_brightness = cdev->max_brightness;
0291     }
0292
0293     ret = regmap_update_bits(regmap, MT6323_ISINK_CON0(led->id),
0294                  MT6323_ISINK_DIM_DUTY_MASK,
0295                  MT6323_ISINK_DIM_DUTY(duty_hw - 1));
0296     if (ret < 0)
0297         goto out;
0298
0299     ret = regmap_update_bits(regmap, MT6323_ISINK_CON1(led->id),
0300                  MT6323_ISINK_DIM_FSEL_MASK,
0301                  MT6323_ISINK_DIM_FSEL(period - 1));
0302 out:
0303     mutex_unlock(&leds->lock);
0304
0305     return ret;
0306 }
0307
0308 static int mt6323_led_set_brightness(struct led_classdev *cdev,
0309                      enum led_brightness brightness)
0310 {
0311     struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
0312     struct mt6323_leds *leds = led->parent;
0313     int ret;
0314
0315     mutex_lock(&leds->lock);
0316
0317     if (!led->current_brightness && brightness) {
0318         ret = mt6323_led_hw_on(cdev, brightness);
0319         if (ret < 0)
0320             goto out;
0321     } else if (brightness) {
0322         ret = mt6323_led_hw_brightness(cdev, brightness);
0323         if (ret < 0)
0324             goto out;
0325     } else {
0326         ret = mt6323_led_hw_off(cdev);
0327         if (ret < 0)
0328             goto out;
0329     }
0330
0331     led->current_brightness = brightness;
0332 out:
0333     mutex_unlock(&leds->lock);
0334
0335     return ret;
0336 }
0337
0338 static int mt6323_led_set_dt_default(struct led_classdev *cdev,
0339                      struct device_node *np)
0340 {
0341     struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
0342     const char *state;
0343     int ret = 0;
0344
0345     state = of_get_property(np, "default-state", NULL);
0346     if (state) {
0347         if (!strcmp(state, "keep")) {
0348             ret = mt6323_get_led_hw_brightness(cdev);
0349             if (ret < 0)
0350                 return ret;
0351             led->current_brightness = ret;
0352             ret = 0;
0353         } else if (!strcmp(state, "on")) {
0354             ret =
0355             mt6323_led_set_brightness(cdev, cdev->max_brightness);
0356         } else  {
0357             ret = mt6323_led_set_brightness(cdev, LED_OFF);
0358         }
0359     }
0360
0361     return ret;
0362 }
0363
0364 static int mt6323_led_probe(struct platform_device *pdev)
0365 {
0366     struct device *dev = &pdev->dev;
0367     struct device_node *np = dev_of_node(dev);
0368     struct device_node *child;
0369     struct mt6397_chip *hw = dev_get_drvdata(dev->parent);
0370     struct mt6323_leds *leds;
0371     struct mt6323_led *led;
0372     int ret;
0373     unsigned int status;
0374     u32 reg;
0375
0376     leds = devm_kzalloc(dev, sizeof(*leds), GFP_KERNEL);
0377     if (!leds)
0378         return -ENOMEM;
0379
0380     platform_set_drvdata(pdev, leds);
0381     leds->dev = dev;
0382
0383     /*
0384      * leds->hw points to the underlying bus for the register
0385      * controlled.
0386      */
0387     leds->hw = hw;
0388     mutex_init(&leds->lock);
0389
0390     status = MT6323_RG_DRV_32K_CK_PDN;
0391     ret = regmap_update_bits(leds->hw->regmap, MT6323_TOP_CKPDN0,
0392                  MT6323_RG_DRV_32K_CK_PDN_MASK, ~status);
0393     if (ret < 0) {
0394         dev_err(leds->dev,
0395             "Failed to update MT6323_TOP_CKPDN0 Register\n");
0396         return ret;
0397     }
0398
0399     for_each_available_child_of_node(np, child) {
0400         struct led_init_data init_data = {};
0401
0402         ret = of_property_read_u32(child, "reg", &reg);
0403         if (ret) {
0404             dev_err(dev, "Failed to read led 'reg' property\n");
0405             goto put_child_node;
0406         }
0407
0408         if (reg >= MT6323_MAX_LEDS || leds->led[reg]) {
0409             dev_err(dev, "Invalid led reg %u\n", reg);
0410             ret = -EINVAL;
0411             goto put_child_node;
0412         }
0413
0414         led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
0415         if (!led) {
0416             ret = -ENOMEM;
0417             goto put_child_node;
0418         }
0419
0420         leds->led[reg] = led;
0421         leds->led[reg]->id = reg;
0422         leds->led[reg]->cdev.max_brightness = MT6323_MAX_BRIGHTNESS;
0423         leds->led[reg]->cdev.brightness_set_blocking =
0424                     mt6323_led_set_brightness;
0425         leds->led[reg]->cdev.blink_set = mt6323_led_set_blink;
0426         leds->led[reg]->cdev.brightness_get =
0427                     mt6323_get_led_hw_brightness;
0428         leds->led[reg]->parent = leds;
0429
0430         ret = mt6323_led_set_dt_default(&leds->led[reg]->cdev, child);
0431         if (ret < 0) {
0432             dev_err(leds->dev,
0433                 "Failed to LED set default from devicetree\n");
0434             goto put_child_node;
0435         }
0436
0437         init_data.fwnode = of_fwnode_handle(child);
0438
0439         ret = devm_led_classdev_register_ext(dev, &leds->led[reg]->cdev,
0440                              &init_data);
0441         if (ret) {
0442             dev_err(dev, "Failed to register LED: %d\n", ret);
0443             goto put_child_node;
0444         }
0445     }
0446
0447     return 0;
0448
0449 put_child_node:
0450     of_node_put(child);
0451     return ret;
0452 }
0453
0454 static int mt6323_led_remove(struct platform_device *pdev)
0455 {
0456     struct mt6323_leds *leds = platform_get_drvdata(pdev);
0457     int i;
0458
0459     /* Turn the LEDs off on driver removal. */
0460     for (i = 0 ; leds->led[i] ; i++)
0461         mt6323_led_hw_off(&leds->led[i]->cdev);
0462
0463     regmap_update_bits(leds->hw->regmap, MT6323_TOP_CKPDN0,
0464                MT6323_RG_DRV_32K_CK_PDN_MASK,
0465                MT6323_RG_DRV_32K_CK_PDN);
0466
0467     mutex_destroy(&leds->lock);
0468
0469     return 0;
0470 }
0471
0472 static const struct of_device_id mt6323_led_dt_match[] = {
0473     { .compatible = "mediatek,mt6323-led" },
0474     {},
0475 };
0476 MODULE_DEVICE_TABLE(of, mt6323_led_dt_match);
0477
0478 static struct platform_driver mt6323_led_driver = {
0479     .probe      = mt6323_led_probe,
0480     .remove     = mt6323_led_remove,
0481     .driver     = {
0482         .name   = "mt6323-led",
0483         .of_match_table = mt6323_led_dt_match,
0484     },
0485 };
0486
0487 module_platform_driver(mt6323_led_driver);
0488
0489 MODULE_DESCRIPTION("LED driver for Mediatek MT6323 PMIC");
0490 MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>");
0491 MODULE_LICENSE("GPL");