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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Analog Devices AD-FMCOMMS1-EBZ board I2C-SPI bridge driver4 *5 * Copyright 2012 Analog Devices Inc.6 * Author: Lars-Peter Clausen <lars@metafoo.de>7 */8 9#include <linux/kernel.h>10#include <linux/module.h>11#include <linux/delay.h>12#include <linux/i2c.h>13#include <linux/gpio/driver.h>14#include <linux/spi/spi.h>15#include <linux/unaligned.h>16 17#define SPI_XCOMM_SETTINGS_LEN_OFFSET 1018#define SPI_XCOMM_SETTINGS_3WIRE BIT(6)19#define SPI_XCOMM_SETTINGS_CS_HIGH BIT(5)20#define SPI_XCOMM_SETTINGS_SAMPLE_END BIT(4)21#define SPI_XCOMM_SETTINGS_CPHA BIT(3)22#define SPI_XCOMM_SETTINGS_CPOL BIT(2)23#define SPI_XCOMM_SETTINGS_CLOCK_DIV_MASK 0x324#define SPI_XCOMM_SETTINGS_CLOCK_DIV_64 0x225#define SPI_XCOMM_SETTINGS_CLOCK_DIV_16 0x126#define SPI_XCOMM_SETTINGS_CLOCK_DIV_4 0x027 28#define SPI_XCOMM_CMD_UPDATE_CONFIG 0x0329#define SPI_XCOMM_CMD_WRITE 0x0430#define SPI_XCOMM_CMD_GPIO_SET 0x0531 32#define SPI_XCOMM_CLOCK 4800000033 34struct spi_xcomm {35 struct i2c_client *i2c;36 37 struct gpio_chip gc;38 39 u16 settings;40 u16 chipselect;41 42 unsigned int current_speed;43 44 u8 buf[63];45};46 47static void spi_xcomm_gpio_set_value(struct gpio_chip *chip,48 unsigned int offset, int val)49{50 struct spi_xcomm *spi_xcomm = gpiochip_get_data(chip);51 unsigned char buf[2];52 53 buf[0] = SPI_XCOMM_CMD_GPIO_SET;54 buf[1] = !!val;55 56 i2c_master_send(spi_xcomm->i2c, buf, 2);57}58 59static int spi_xcomm_gpio_get_direction(struct gpio_chip *chip,60 unsigned int offset)61{62 return GPIO_LINE_DIRECTION_OUT;63}64 65static int spi_xcomm_gpio_add(struct spi_xcomm *spi_xcomm)66{67 struct device *dev = &spi_xcomm->i2c->dev;68 69 if (!IS_ENABLED(CONFIG_GPIOLIB))70 return 0;71 72 spi_xcomm->gc.get_direction = spi_xcomm_gpio_get_direction;73 spi_xcomm->gc.set = spi_xcomm_gpio_set_value;74 spi_xcomm->gc.can_sleep = 1;75 spi_xcomm->gc.base = -1;76 spi_xcomm->gc.ngpio = 1;77 spi_xcomm->gc.label = spi_xcomm->i2c->name;78 spi_xcomm->gc.owner = THIS_MODULE;79 80 return devm_gpiochip_add_data(dev, &spi_xcomm->gc, spi_xcomm);81}82 83static int spi_xcomm_sync_config(struct spi_xcomm *spi_xcomm, unsigned int len)84{85 u16 settings;86 u8 *buf = spi_xcomm->buf;87 88 settings = spi_xcomm->settings;89 settings |= len << SPI_XCOMM_SETTINGS_LEN_OFFSET;90 91 buf[0] = SPI_XCOMM_CMD_UPDATE_CONFIG;92 put_unaligned_be16(settings, &buf[1]);93 put_unaligned_be16(spi_xcomm->chipselect, &buf[3]);94 95 return i2c_master_send(spi_xcomm->i2c, buf, 5);96}97 98static void spi_xcomm_chipselect(struct spi_xcomm *spi_xcomm,99 struct spi_device *spi, int is_active)100{101 unsigned long cs = spi_get_chipselect(spi, 0);102 u16 chipselect = spi_xcomm->chipselect;103 104 if (is_active)105 chipselect |= BIT(cs);106 else107 chipselect &= ~BIT(cs);108 109 spi_xcomm->chipselect = chipselect;110}111 112static int spi_xcomm_setup_transfer(struct spi_xcomm *spi_xcomm,113 struct spi_device *spi, struct spi_transfer *t,114 unsigned int *settings)115{116 if (t->len > 62)117 return -EINVAL;118 119 if (t->speed_hz != spi_xcomm->current_speed) {120 unsigned int divider;121 122 divider = DIV_ROUND_UP(SPI_XCOMM_CLOCK, t->speed_hz);123 if (divider >= 64)124 *settings |= SPI_XCOMM_SETTINGS_CLOCK_DIV_64;125 else if (divider >= 16)126 *settings |= SPI_XCOMM_SETTINGS_CLOCK_DIV_16;127 else128 *settings |= SPI_XCOMM_SETTINGS_CLOCK_DIV_4;129 130 spi_xcomm->current_speed = t->speed_hz;131 }132 133 if (spi->mode & SPI_CPOL)134 *settings |= SPI_XCOMM_SETTINGS_CPOL;135 else136 *settings &= ~SPI_XCOMM_SETTINGS_CPOL;137 138 if (spi->mode & SPI_CPHA)139 *settings &= ~SPI_XCOMM_SETTINGS_CPHA;140 else141 *settings |= SPI_XCOMM_SETTINGS_CPHA;142 143 if (spi->mode & SPI_3WIRE)144 *settings |= SPI_XCOMM_SETTINGS_3WIRE;145 else146 *settings &= ~SPI_XCOMM_SETTINGS_3WIRE;147 148 return 0;149}150 151static int spi_xcomm_txrx_bufs(struct spi_xcomm *spi_xcomm,152 struct spi_device *spi, struct spi_transfer *t)153{154 int ret;155 156 if (t->tx_buf) {157 spi_xcomm->buf[0] = SPI_XCOMM_CMD_WRITE;158 memcpy(spi_xcomm->buf + 1, t->tx_buf, t->len);159 160 ret = i2c_master_send(spi_xcomm->i2c, spi_xcomm->buf, t->len + 1);161 if (ret < 0)162 return ret;163 if (ret != t->len + 1)164 return -EIO;165 } else if (t->rx_buf) {166 ret = i2c_master_recv(spi_xcomm->i2c, t->rx_buf, t->len);167 if (ret < 0)168 return ret;169 if (ret != t->len)170 return -EIO;171 }172 173 return t->len;174}175 176static int spi_xcomm_transfer_one(struct spi_controller *host,177 struct spi_message *msg)178{179 struct spi_xcomm *spi_xcomm = spi_controller_get_devdata(host);180 unsigned int settings = spi_xcomm->settings;181 struct spi_device *spi = msg->spi;182 unsigned int cs_change = 0;183 struct spi_transfer *t;184 bool is_first = true;185 int status = 0;186 bool is_last;187 188 spi_xcomm_chipselect(spi_xcomm, spi, true);189 190 list_for_each_entry(t, &msg->transfers, transfer_list) {191 if (!t->tx_buf && !t->rx_buf && t->len) {192 status = -EINVAL;193 break;194 }195 196 status = spi_xcomm_setup_transfer(spi_xcomm, spi, t, &settings);197 if (status < 0)198 break;199 200 is_last = list_is_last(&t->transfer_list, &msg->transfers);201 cs_change = t->cs_change;202 203 if (cs_change ^ is_last)204 settings |= BIT(5);205 else206 settings &= ~BIT(5);207 208 if (t->rx_buf) {209 spi_xcomm->settings = settings;210 status = spi_xcomm_sync_config(spi_xcomm, t->len);211 if (status < 0)212 break;213 } else if (settings != spi_xcomm->settings || is_first) {214 spi_xcomm->settings = settings;215 status = spi_xcomm_sync_config(spi_xcomm, 0);216 if (status < 0)217 break;218 }219 220 if (t->len) {221 status = spi_xcomm_txrx_bufs(spi_xcomm, spi, t);222 223 if (status < 0)224 break;225 226 if (status > 0)227 msg->actual_length += status;228 }229 status = 0;230 231 spi_transfer_delay_exec(t);232 233 is_first = false;234 }235 236 if (status != 0 || !cs_change)237 spi_xcomm_chipselect(spi_xcomm, spi, false);238 239 msg->status = status;240 spi_finalize_current_message(host);241 242 return status;243}244 245static int spi_xcomm_probe(struct i2c_client *i2c)246{247 struct spi_xcomm *spi_xcomm;248 struct spi_controller *host;249 int ret;250 251 host = devm_spi_alloc_host(&i2c->dev, sizeof(*spi_xcomm));252 if (!host)253 return -ENOMEM;254 255 spi_xcomm = spi_controller_get_devdata(host);256 spi_xcomm->i2c = i2c;257 258 host->num_chipselect = 16;259 host->mode_bits = SPI_CPHA | SPI_CPOL | SPI_3WIRE;260 host->bits_per_word_mask = SPI_BPW_MASK(8);261 host->flags = SPI_CONTROLLER_HALF_DUPLEX;262 host->transfer_one_message = spi_xcomm_transfer_one;263 host->dev.of_node = i2c->dev.of_node;264 265 ret = devm_spi_register_controller(&i2c->dev, host);266 if (ret < 0)267 return ret;268 269 return spi_xcomm_gpio_add(spi_xcomm);270}271 272static const struct i2c_device_id spi_xcomm_ids[] = {273 { "spi-xcomm" },274 { },275};276MODULE_DEVICE_TABLE(i2c, spi_xcomm_ids);277 278static struct i2c_driver spi_xcomm_driver = {279 .driver = {280 .name = "spi-xcomm",281 },282 .id_table = spi_xcomm_ids,283 .probe = spi_xcomm_probe,284};285module_i2c_driver(spi_xcomm_driver);286 287MODULE_LICENSE("GPL");288MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");289MODULE_DESCRIPTION("Analog Devices AD-FMCOMMS1-EBZ board I2C-SPI bridge driver");290