drivers/mfd/lochnagar-i2c.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Lochnagar I2C bus interface
0004  *
0005  * Copyright (c) 2012-2018 Cirrus Logic, Inc. and
0006  *                         Cirrus Logic International Semiconductor Ltd.
0007  *
0008  * Author: Charles Keepax <ckeepax@opensource.cirrus.com>
0009  */
0010
0011 #include <linux/delay.h>
0012 #include <linux/device.h>
0013 #include <linux/err.h>
0014 #include <linux/gpio/consumer.h>
0015 #include <linux/i2c.h>
0016 #include <linux/lockdep.h>
0017 #include <linux/mfd/core.h>
0018 #include <linux/mutex.h>
0019 #include <linux/of.h>
0020 #include <linux/of_platform.h>
0021 #include <linux/regmap.h>
0022
0023 #include <linux/mfd/lochnagar.h>
0024 #include <linux/mfd/lochnagar1_regs.h>
0025 #include <linux/mfd/lochnagar2_regs.h>
0026
0027 #define LOCHNAGAR_BOOT_RETRIES      10
0028 #define LOCHNAGAR_BOOT_DELAY_MS     350
0029
0030 #define LOCHNAGAR_CONFIG_POLL_US    10000
0031
0032 static bool lochnagar1_readable_register(struct device *dev, unsigned int reg)
0033 {
0034     switch (reg) {
0035     case LOCHNAGAR_SOFTWARE_RESET:
0036     case LOCHNAGAR_FIRMWARE_ID1...LOCHNAGAR_FIRMWARE_ID2:
0037     case LOCHNAGAR1_CDC_AIF1_SEL...LOCHNAGAR1_CDC_AIF3_SEL:
0038     case LOCHNAGAR1_CDC_MCLK1_SEL...LOCHNAGAR1_CDC_MCLK2_SEL:
0039     case LOCHNAGAR1_CDC_AIF_CTRL1...LOCHNAGAR1_CDC_AIF_CTRL2:
0040     case LOCHNAGAR1_EXT_AIF_CTRL:
0041     case LOCHNAGAR1_DSP_AIF1_SEL...LOCHNAGAR1_DSP_AIF2_SEL:
0042     case LOCHNAGAR1_DSP_CLKIN_SEL:
0043     case LOCHNAGAR1_DSP_AIF:
0044     case LOCHNAGAR1_GF_AIF1...LOCHNAGAR1_GF_AIF2:
0045     case LOCHNAGAR1_PSIA_AIF:
0046     case LOCHNAGAR1_PSIA1_SEL...LOCHNAGAR1_PSIA2_SEL:
0047     case LOCHNAGAR1_SPDIF_AIF_SEL:
0048     case LOCHNAGAR1_GF_AIF3_SEL...LOCHNAGAR1_GF_AIF4_SEL:
0049     case LOCHNAGAR1_GF_CLKOUT1_SEL:
0050     case LOCHNAGAR1_GF_AIF1_SEL...LOCHNAGAR1_GF_AIF2_SEL:
0051     case LOCHNAGAR1_GF_GPIO2...LOCHNAGAR1_GF_GPIO7:
0052     case LOCHNAGAR1_RST:
0053     case LOCHNAGAR1_LED1...LOCHNAGAR1_LED2:
0054     case LOCHNAGAR1_I2C_CTRL:
0055         return true;
0056     default:
0057         return false;
0058     }
0059 }
0060
0061 static const struct regmap_config lochnagar1_i2c_regmap = {
0062     .reg_bits = 8,
0063     .val_bits = 8,
0064     .reg_format_endian = REGMAP_ENDIAN_BIG,
0065     .val_format_endian = REGMAP_ENDIAN_BIG,
0066
0067     .max_register = 0x50,
0068     .readable_reg = lochnagar1_readable_register,
0069
0070     .use_single_read = true,
0071     .use_single_write = true,
0072
0073     .cache_type = REGCACHE_RBTREE,
0074 };
0075
0076 static const struct reg_sequence lochnagar1_patch[] = {
0077     { 0x40, 0x0083 },
0078     { 0x47, 0x0018 },
0079     { 0x50, 0x0000 },
0080 };
0081
0082 static bool lochnagar2_readable_register(struct device *dev, unsigned int reg)
0083 {
0084     switch (reg) {
0085     case LOCHNAGAR_SOFTWARE_RESET:
0086     case LOCHNAGAR_FIRMWARE_ID1...LOCHNAGAR_FIRMWARE_ID2:
0087     case LOCHNAGAR2_CDC_AIF1_CTRL...LOCHNAGAR2_CDC_AIF3_CTRL:
0088     case LOCHNAGAR2_DSP_AIF1_CTRL...LOCHNAGAR2_DSP_AIF2_CTRL:
0089     case LOCHNAGAR2_PSIA1_CTRL...LOCHNAGAR2_PSIA2_CTRL:
0090     case LOCHNAGAR2_GF_AIF3_CTRL...LOCHNAGAR2_GF_AIF4_CTRL:
0091     case LOCHNAGAR2_GF_AIF1_CTRL...LOCHNAGAR2_GF_AIF2_CTRL:
0092     case LOCHNAGAR2_SPDIF_AIF_CTRL:
0093     case LOCHNAGAR2_USB_AIF1_CTRL...LOCHNAGAR2_USB_AIF2_CTRL:
0094     case LOCHNAGAR2_ADAT_AIF_CTRL:
0095     case LOCHNAGAR2_CDC_MCLK1_CTRL...LOCHNAGAR2_CDC_MCLK2_CTRL:
0096     case LOCHNAGAR2_DSP_CLKIN_CTRL:
0097     case LOCHNAGAR2_PSIA1_MCLK_CTRL...LOCHNAGAR2_PSIA2_MCLK_CTRL:
0098     case LOCHNAGAR2_SPDIF_MCLK_CTRL:
0099     case LOCHNAGAR2_GF_CLKOUT1_CTRL...LOCHNAGAR2_GF_CLKOUT2_CTRL:
0100     case LOCHNAGAR2_ADAT_MCLK_CTRL:
0101     case LOCHNAGAR2_SOUNDCARD_MCLK_CTRL:
0102     case LOCHNAGAR2_GPIO_FPGA_GPIO1...LOCHNAGAR2_GPIO_FPGA_GPIO6:
0103     case LOCHNAGAR2_GPIO_CDC_GPIO1...LOCHNAGAR2_GPIO_CDC_GPIO8:
0104     case LOCHNAGAR2_GPIO_DSP_GPIO1...LOCHNAGAR2_GPIO_DSP_GPIO6:
0105     case LOCHNAGAR2_GPIO_GF_GPIO2...LOCHNAGAR2_GPIO_GF_GPIO7:
0106     case LOCHNAGAR2_GPIO_CDC_AIF1_BCLK...LOCHNAGAR2_GPIO_CDC_AIF3_TXDAT:
0107     case LOCHNAGAR2_GPIO_DSP_AIF1_BCLK...LOCHNAGAR2_GPIO_DSP_AIF2_TXDAT:
0108     case LOCHNAGAR2_GPIO_PSIA1_BCLK...LOCHNAGAR2_GPIO_PSIA2_TXDAT:
0109     case LOCHNAGAR2_GPIO_GF_AIF3_BCLK...LOCHNAGAR2_GPIO_GF_AIF4_TXDAT:
0110     case LOCHNAGAR2_GPIO_GF_AIF1_BCLK...LOCHNAGAR2_GPIO_GF_AIF2_TXDAT:
0111     case LOCHNAGAR2_GPIO_DSP_UART1_RX...LOCHNAGAR2_GPIO_DSP_UART2_TX:
0112     case LOCHNAGAR2_GPIO_GF_UART2_RX...LOCHNAGAR2_GPIO_GF_UART2_TX:
0113     case LOCHNAGAR2_GPIO_USB_UART_RX:
0114     case LOCHNAGAR2_GPIO_CDC_PDMCLK1...LOCHNAGAR2_GPIO_CDC_PDMDAT2:
0115     case LOCHNAGAR2_GPIO_CDC_DMICCLK1...LOCHNAGAR2_GPIO_CDC_DMICDAT4:
0116     case LOCHNAGAR2_GPIO_DSP_DMICCLK1...LOCHNAGAR2_GPIO_DSP_DMICDAT2:
0117     case LOCHNAGAR2_GPIO_I2C2_SCL...LOCHNAGAR2_GPIO_I2C4_SDA:
0118     case LOCHNAGAR2_GPIO_DSP_STANDBY:
0119     case LOCHNAGAR2_GPIO_CDC_MCLK1...LOCHNAGAR2_GPIO_CDC_MCLK2:
0120     case LOCHNAGAR2_GPIO_DSP_CLKIN:
0121     case LOCHNAGAR2_GPIO_PSIA1_MCLK...LOCHNAGAR2_GPIO_PSIA2_MCLK:
0122     case LOCHNAGAR2_GPIO_GF_GPIO1...LOCHNAGAR2_GPIO_GF_GPIO5:
0123     case LOCHNAGAR2_GPIO_DSP_GPIO20:
0124     case LOCHNAGAR2_GPIO_CHANNEL1...LOCHNAGAR2_GPIO_CHANNEL16:
0125     case LOCHNAGAR2_MINICARD_RESETS:
0126     case LOCHNAGAR2_ANALOGUE_PATH_CTRL1...LOCHNAGAR2_ANALOGUE_PATH_CTRL2:
0127     case LOCHNAGAR2_COMMS_CTRL4:
0128     case LOCHNAGAR2_SPDIF_CTRL:
0129     case LOCHNAGAR2_IMON_CTRL1...LOCHNAGAR2_IMON_CTRL4:
0130     case LOCHNAGAR2_IMON_DATA1...LOCHNAGAR2_IMON_DATA2:
0131     case LOCHNAGAR2_POWER_CTRL:
0132     case LOCHNAGAR2_MICVDD_CTRL1:
0133     case LOCHNAGAR2_MICVDD_CTRL2:
0134     case LOCHNAGAR2_VDDCORE_CDC_CTRL1:
0135     case LOCHNAGAR2_VDDCORE_CDC_CTRL2:
0136     case LOCHNAGAR2_SOUNDCARD_AIF_CTRL:
0137         return true;
0138     default:
0139         return false;
0140     }
0141 }
0142
0143 static bool lochnagar2_volatile_register(struct device *dev, unsigned int reg)
0144 {
0145     switch (reg) {
0146     case LOCHNAGAR2_GPIO_CHANNEL1...LOCHNAGAR2_GPIO_CHANNEL16:
0147     case LOCHNAGAR2_ANALOGUE_PATH_CTRL1:
0148     case LOCHNAGAR2_IMON_CTRL3...LOCHNAGAR2_IMON_CTRL4:
0149     case LOCHNAGAR2_IMON_DATA1...LOCHNAGAR2_IMON_DATA2:
0150         return true;
0151     default:
0152         return false;
0153     }
0154 }
0155
0156 static const struct regmap_config lochnagar2_i2c_regmap = {
0157     .reg_bits = 16,
0158     .val_bits = 16,
0159     .reg_format_endian = REGMAP_ENDIAN_BIG,
0160     .val_format_endian = REGMAP_ENDIAN_BIG,
0161
0162     .max_register = 0x1F1F,
0163     .readable_reg = lochnagar2_readable_register,
0164     .volatile_reg = lochnagar2_volatile_register,
0165
0166     .cache_type = REGCACHE_RBTREE,
0167 };
0168
0169 static const struct reg_sequence lochnagar2_patch[] = {
0170     { 0x00EE, 0x0000 },
0171 };
0172
0173 struct lochnagar_config {
0174     int id;
0175     const char * const name;
0176     enum lochnagar_type type;
0177     const struct regmap_config *regmap;
0178     const struct reg_sequence *patch;
0179     int npatch;
0180 };
0181
0182 static struct lochnagar_config lochnagar_configs[] = {
0183     {
0184         .id = 0x50,
0185         .name = "lochnagar1",
0186         .type = LOCHNAGAR1,
0187         .regmap = &lochnagar1_i2c_regmap,
0188         .patch = lochnagar1_patch,
0189         .npatch = ARRAY_SIZE(lochnagar1_patch),
0190     },
0191     {
0192         .id = 0xCB58,
0193         .name = "lochnagar2",
0194         .type = LOCHNAGAR2,
0195         .regmap = &lochnagar2_i2c_regmap,
0196         .patch = lochnagar2_patch,
0197         .npatch = ARRAY_SIZE(lochnagar2_patch),
0198     },
0199 };
0200
0201 static const struct of_device_id lochnagar_of_match[] = {
0202     { .compatible = "cirrus,lochnagar1", .data = &lochnagar_configs[0] },
0203     { .compatible = "cirrus,lochnagar2", .data = &lochnagar_configs[1] },
0204     {},
0205 };
0206
0207 static int lochnagar_wait_for_boot(struct regmap *regmap, unsigned int *id)
0208 {
0209     int i, ret;
0210
0211     for (i = 0; i < LOCHNAGAR_BOOT_RETRIES; ++i) {
0212         msleep(LOCHNAGAR_BOOT_DELAY_MS);
0213
0214         /* The reset register will return the device ID when read */
0215         ret = regmap_read(regmap, LOCHNAGAR_SOFTWARE_RESET, id);
0216         if (!ret)
0217             return ret;
0218     }
0219
0220     return -ETIMEDOUT;
0221 }
0222
0223 /**
0224  * lochnagar_update_config - Synchronise the boards analogue configuration to
0225  *                           the hardware.
0226  *
0227  * @lochnagar: A pointer to the primary core data structure.
0228  *
0229  * Return: Zero on success or an appropriate negative error code on failure.
0230  */
0231 int lochnagar_update_config(struct lochnagar *lochnagar)
0232 {
0233     struct regmap *regmap = lochnagar->regmap;
0234     unsigned int done = LOCHNAGAR2_ANALOGUE_PATH_UPDATE_STS_MASK;
0235     int timeout_ms = LOCHNAGAR_BOOT_DELAY_MS * LOCHNAGAR_BOOT_RETRIES;
0236     unsigned int val = 0;
0237     int ret;
0238
0239     lockdep_assert_held(&lochnagar->analogue_config_lock);
0240
0241     if (lochnagar->type != LOCHNAGAR2)
0242         return 0;
0243
0244     /*
0245      * Toggle the ANALOGUE_PATH_UPDATE bit and wait for the device to
0246      * acknowledge that any outstanding changes to the analogue
0247      * configuration have been applied.
0248      */
0249     ret = regmap_write(regmap, LOCHNAGAR2_ANALOGUE_PATH_CTRL1, 0);
0250     if (ret < 0)
0251         return ret;
0252
0253     ret = regmap_write(regmap, LOCHNAGAR2_ANALOGUE_PATH_CTRL1,
0254                LOCHNAGAR2_ANALOGUE_PATH_UPDATE_MASK);
0255     if (ret < 0)
0256         return ret;
0257
0258     ret = regmap_read_poll_timeout(regmap,
0259                        LOCHNAGAR2_ANALOGUE_PATH_CTRL1, val,
0260                        (val & done), LOCHNAGAR_CONFIG_POLL_US,
0261                        timeout_ms * 1000);
0262     if (ret < 0)
0263         return ret;
0264
0265     return 0;
0266 }
0267 EXPORT_SYMBOL_GPL(lochnagar_update_config);
0268
0269 static int lochnagar_i2c_probe(struct i2c_client *i2c)
0270 {
0271     struct device *dev = &i2c->dev;
0272     const struct lochnagar_config *config = NULL;
0273     const struct of_device_id *of_id;
0274     struct lochnagar *lochnagar;
0275     struct gpio_desc *reset, *present;
0276     unsigned int val;
0277     unsigned int firmwareid;
0278     unsigned int devid, rev;
0279     int ret;
0280
0281     lochnagar = devm_kzalloc(dev, sizeof(*lochnagar), GFP_KERNEL);
0282     if (!lochnagar)
0283         return -ENOMEM;
0284
0285     of_id = of_match_device(lochnagar_of_match, dev);
0286     if (!of_id)
0287         return -EINVAL;
0288
0289     config = of_id->data;
0290
0291     lochnagar->dev = dev;
0292     mutex_init(&lochnagar->analogue_config_lock);
0293
0294     dev_set_drvdata(dev, lochnagar);
0295
0296     reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
0297     if (IS_ERR(reset)) {
0298         ret = PTR_ERR(reset);
0299         dev_err(dev, "Failed to get reset GPIO: %d\n", ret);
0300         return ret;
0301     }
0302
0303     present = devm_gpiod_get_optional(dev, "present", GPIOD_OUT_HIGH);
0304     if (IS_ERR(present)) {
0305         ret = PTR_ERR(present);
0306         dev_err(dev, "Failed to get present GPIO: %d\n", ret);
0307         return ret;
0308     }
0309
0310     /* Leave the Lochnagar in reset for a reasonable amount of time */
0311     msleep(20);
0312
0313     /* Bring Lochnagar out of reset */
0314     gpiod_set_value_cansleep(reset, 1);
0315
0316     /* Identify Lochnagar */
0317     lochnagar->type = config->type;
0318
0319     lochnagar->regmap = devm_regmap_init_i2c(i2c, config->regmap);
0320     if (IS_ERR(lochnagar->regmap)) {
0321         ret = PTR_ERR(lochnagar->regmap);
0322         dev_err(dev, "Failed to allocate register map: %d\n", ret);
0323         return ret;
0324     }
0325
0326     /* Wait for Lochnagar to boot */
0327     ret = lochnagar_wait_for_boot(lochnagar->regmap, &val);
0328     if (ret < 0) {
0329         dev_err(dev, "Failed to read device ID: %d\n", ret);
0330         return ret;
0331     }
0332
0333     devid = val & LOCHNAGAR_DEVICE_ID_MASK;
0334     rev = val & LOCHNAGAR_REV_ID_MASK;
0335
0336     if (devid != config->id) {
0337         dev_err(dev,
0338             "ID does not match %s (expected 0x%x got 0x%x)\n",
0339             config->name, config->id, devid);
0340         return -ENODEV;
0341     }
0342
0343     /* Identify firmware */
0344     ret = regmap_read(lochnagar->regmap, LOCHNAGAR_FIRMWARE_ID1, &val);
0345     if (ret < 0) {
0346         dev_err(dev, "Failed to read firmware id 1: %d\n", ret);
0347         return ret;
0348     }
0349
0350     firmwareid = val;
0351
0352     ret = regmap_read(lochnagar->regmap, LOCHNAGAR_FIRMWARE_ID2, &val);
0353     if (ret < 0) {
0354         dev_err(dev, "Failed to read firmware id 2: %d\n", ret);
0355         return ret;
0356     }
0357
0358     firmwareid |= (val << config->regmap->val_bits);
0359
0360     dev_info(dev, "Found %s (0x%x) revision %u firmware 0x%.6x\n",
0361          config->name, devid, rev + 1, firmwareid);
0362
0363     ret = regmap_register_patch(lochnagar->regmap, config->patch,
0364                     config->npatch);
0365     if (ret < 0) {
0366         dev_err(dev, "Failed to register patch: %d\n", ret);
0367         return ret;
0368     }
0369
0370     ret = devm_of_platform_populate(dev);
0371     if (ret < 0) {
0372         dev_err(dev, "Failed to populate child nodes: %d\n", ret);
0373         return ret;
0374     }
0375
0376     return ret;
0377 }
0378
0379 static struct i2c_driver lochnagar_i2c_driver = {
0380     .driver = {
0381         .name = "lochnagar",
0382         .of_match_table = of_match_ptr(lochnagar_of_match),
0383         .suppress_bind_attrs = true,
0384     },
0385     .probe_new = lochnagar_i2c_probe,
0386 };
0387
0388 static int __init lochnagar_i2c_init(void)
0389 {
0390     int ret;
0391
0392     ret = i2c_add_driver(&lochnagar_i2c_driver);
0393     if (ret)
0394         pr_err("Failed to register Lochnagar driver: %d\n", ret);
0395
0396     return ret;
0397 }
0398 subsys_initcall(lochnagar_i2c_init);