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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Intel La Jolla Cove Adapter USB-SPI driver4 *5 * Copyright (c) 2023, Intel Corporation.6 */7 8#include <linux/auxiliary_bus.h>9#include <linux/bitfield.h>10#include <linux/bits.h>11#include <linux/dev_printk.h>12#include <linux/module.h>13#include <linux/spi/spi.h>14#include <linux/usb/ljca.h>15 16#define LJCA_SPI_BUS_MAX_HZ 4800000017 18#define LJCA_SPI_BUF_SIZE 60u19#define LJCA_SPI_MAX_XFER_SIZE \20 (LJCA_SPI_BUF_SIZE - sizeof(struct ljca_spi_xfer_packet))21 22#define LJCA_SPI_CLK_MODE_POLARITY BIT(0)23#define LJCA_SPI_CLK_MODE_PHASE BIT(1)24 25#define LJCA_SPI_XFER_INDICATOR_ID GENMASK(5, 0)26#define LJCA_SPI_XFER_INDICATOR_CMPL BIT(6)27#define LJCA_SPI_XFER_INDICATOR_INDEX BIT(7)28 29/* SPI commands */30enum ljca_spi_cmd {31 LJCA_SPI_INIT = 1,32 LJCA_SPI_READ,33 LJCA_SPI_WRITE,34 LJCA_SPI_WRITEREAD,35 LJCA_SPI_DEINIT,36};37 38enum {39 LJCA_SPI_BUS_SPEED_24M,40 LJCA_SPI_BUS_SPEED_12M,41 LJCA_SPI_BUS_SPEED_8M,42 LJCA_SPI_BUS_SPEED_6M,43 LJCA_SPI_BUS_SPEED_4_8M, /*4.8MHz*/44 LJCA_SPI_BUS_SPEED_MIN = LJCA_SPI_BUS_SPEED_4_8M,45};46 47enum {48 LJCA_SPI_CLOCK_LOW_POLARITY,49 LJCA_SPI_CLOCK_HIGH_POLARITY,50};51 52enum {53 LJCA_SPI_CLOCK_FIRST_PHASE,54 LJCA_SPI_CLOCK_SECOND_PHASE,55};56 57struct ljca_spi_init_packet {58 u8 index;59 u8 speed;60 u8 mode;61} __packed;62 63struct ljca_spi_xfer_packet {64 u8 indicator;65 u8 len;66 u8 data[] __counted_by(len);67} __packed;68 69struct ljca_spi_dev {70 struct ljca_client *ljca;71 struct spi_controller *controller;72 struct ljca_spi_info *spi_info;73 u8 speed;74 u8 mode;75 76 u8 obuf[LJCA_SPI_BUF_SIZE];77 u8 ibuf[LJCA_SPI_BUF_SIZE];78};79 80static int ljca_spi_read_write(struct ljca_spi_dev *ljca_spi, const u8 *w_data,81 u8 *r_data, int len, int id, int complete,82 int cmd)83{84 struct ljca_spi_xfer_packet *w_packet =85 (struct ljca_spi_xfer_packet *)ljca_spi->obuf;86 struct ljca_spi_xfer_packet *r_packet =87 (struct ljca_spi_xfer_packet *)ljca_spi->ibuf;88 int ret;89 90 w_packet->indicator = FIELD_PREP(LJCA_SPI_XFER_INDICATOR_ID, id) |91 FIELD_PREP(LJCA_SPI_XFER_INDICATOR_CMPL, complete) |92 FIELD_PREP(LJCA_SPI_XFER_INDICATOR_INDEX,93 ljca_spi->spi_info->id);94 95 if (cmd == LJCA_SPI_READ) {96 w_packet->len = sizeof(u16);97 *(__le16 *)&w_packet->data[0] = cpu_to_le16(len);98 } else {99 w_packet->len = len;100 memcpy(w_packet->data, w_data, len);101 }102 103 ret = ljca_transfer(ljca_spi->ljca, cmd, (u8 *)w_packet,104 struct_size(w_packet, data, w_packet->len),105 (u8 *)r_packet, LJCA_SPI_BUF_SIZE);106 if (ret < 0)107 return ret;108 else if (ret < sizeof(*r_packet) || r_packet->len <= 0)109 return -EIO;110 111 if (r_data)112 memcpy(r_data, r_packet->data, r_packet->len);113 114 return 0;115}116 117static int ljca_spi_init(struct ljca_spi_dev *ljca_spi, u8 div, u8 mode)118{119 struct ljca_spi_init_packet w_packet = {};120 int ret;121 122 if (ljca_spi->mode == mode && ljca_spi->speed == div)123 return 0;124 125 w_packet.index = ljca_spi->spi_info->id;126 w_packet.speed = div;127 w_packet.mode = FIELD_PREP(LJCA_SPI_CLK_MODE_POLARITY,128 (mode & SPI_CPOL) ? LJCA_SPI_CLOCK_HIGH_POLARITY :129 LJCA_SPI_CLOCK_LOW_POLARITY) |130 FIELD_PREP(LJCA_SPI_CLK_MODE_PHASE,131 (mode & SPI_CPHA) ? LJCA_SPI_CLOCK_SECOND_PHASE :132 LJCA_SPI_CLOCK_FIRST_PHASE);133 134 ret = ljca_transfer(ljca_spi->ljca, LJCA_SPI_INIT, (u8 *)&w_packet,135 sizeof(w_packet), NULL, 0);136 if (ret < 0)137 return ret;138 139 ljca_spi->mode = mode;140 ljca_spi->speed = div;141 142 return 0;143}144 145static int ljca_spi_deinit(struct ljca_spi_dev *ljca_spi)146{147 struct ljca_spi_init_packet w_packet = {};148 int ret;149 150 w_packet.index = ljca_spi->spi_info->id;151 152 ret = ljca_transfer(ljca_spi->ljca, LJCA_SPI_DEINIT, (u8 *)&w_packet,153 sizeof(w_packet), NULL, 0);154 155 return ret < 0 ? ret : 0;156}157 158static inline int ljca_spi_transfer(struct ljca_spi_dev *ljca_spi,159 const u8 *tx_data, u8 *rx_data, u16 len)160{161 int complete, cur_len;162 int remaining = len;163 int cmd, ret, i;164 int offset = 0;165 166 if (tx_data && rx_data)167 cmd = LJCA_SPI_WRITEREAD;168 else if (tx_data)169 cmd = LJCA_SPI_WRITE;170 else if (rx_data)171 cmd = LJCA_SPI_READ;172 else173 return -EINVAL;174 175 for (i = 0; remaining > 0; i++) {176 cur_len = min_t(unsigned int, remaining, LJCA_SPI_MAX_XFER_SIZE);177 complete = (cur_len == remaining);178 179 ret = ljca_spi_read_write(ljca_spi,180 tx_data ? tx_data + offset : NULL,181 rx_data ? rx_data + offset : NULL,182 cur_len, i, complete, cmd);183 if (ret)184 return ret;185 186 offset += cur_len;187 remaining -= cur_len;188 }189 190 return 0;191}192 193static int ljca_spi_transfer_one(struct spi_controller *controller,194 struct spi_device *spi,195 struct spi_transfer *xfer)196{197 u8 div = DIV_ROUND_UP(controller->max_speed_hz, xfer->speed_hz) / 2 - 1;198 struct ljca_spi_dev *ljca_spi = spi_controller_get_devdata(controller);199 int ret;200 201 div = min_t(u8, LJCA_SPI_BUS_SPEED_MIN, div);202 203 ret = ljca_spi_init(ljca_spi, div, spi->mode);204 if (ret) {205 dev_err(&ljca_spi->ljca->auxdev.dev,206 "cannot initialize transfer ret %d\n", ret);207 return ret;208 }209 210 ret = ljca_spi_transfer(ljca_spi, xfer->tx_buf, xfer->rx_buf, xfer->len);211 if (ret)212 dev_err(&ljca_spi->ljca->auxdev.dev,213 "transfer failed len: %d\n", xfer->len);214 215 return ret;216}217 218static int ljca_spi_probe(struct auxiliary_device *auxdev,219 const struct auxiliary_device_id *aux_dev_id)220{221 struct ljca_client *ljca = auxiliary_dev_to_ljca_client(auxdev);222 struct spi_controller *controller;223 struct ljca_spi_dev *ljca_spi;224 int ret;225 226 controller = devm_spi_alloc_host(&auxdev->dev, sizeof(*ljca_spi));227 if (!controller)228 return -ENOMEM;229 230 ljca_spi = spi_controller_get_devdata(controller);231 ljca_spi->ljca = ljca;232 ljca_spi->spi_info = dev_get_platdata(&auxdev->dev);233 ljca_spi->controller = controller;234 235 controller->bus_num = -1;236 controller->mode_bits = SPI_CPHA | SPI_CPOL;237 controller->transfer_one = ljca_spi_transfer_one;238 controller->auto_runtime_pm = false;239 controller->max_speed_hz = LJCA_SPI_BUS_MAX_HZ;240 241 device_set_node(&ljca_spi->controller->dev, dev_fwnode(&auxdev->dev));242 auxiliary_set_drvdata(auxdev, controller);243 244 ret = spi_register_controller(controller);245 if (ret)246 dev_err(&auxdev->dev, "Failed to register controller\n");247 248 return ret;249}250 251static void ljca_spi_dev_remove(struct auxiliary_device *auxdev)252{253 struct spi_controller *controller = auxiliary_get_drvdata(auxdev);254 struct ljca_spi_dev *ljca_spi = spi_controller_get_devdata(controller);255 256 spi_unregister_controller(controller);257 ljca_spi_deinit(ljca_spi);258}259 260static int ljca_spi_dev_suspend(struct device *dev)261{262 struct spi_controller *controller = dev_get_drvdata(dev);263 264 return spi_controller_suspend(controller);265}266 267static int ljca_spi_dev_resume(struct device *dev)268{269 struct spi_controller *controller = dev_get_drvdata(dev);270 271 return spi_controller_resume(controller);272}273 274static const struct dev_pm_ops ljca_spi_pm = {275 SYSTEM_SLEEP_PM_OPS(ljca_spi_dev_suspend, ljca_spi_dev_resume)276};277 278static const struct auxiliary_device_id ljca_spi_id_table[] = {279 { "usb_ljca.ljca-spi", 0 },280 { /* sentinel */ }281};282MODULE_DEVICE_TABLE(auxiliary, ljca_spi_id_table);283 284static struct auxiliary_driver ljca_spi_driver = {285 .driver.pm = &ljca_spi_pm,286 .probe = ljca_spi_probe,287 .remove = ljca_spi_dev_remove,288 .id_table = ljca_spi_id_table,289};290module_auxiliary_driver(ljca_spi_driver);291 292MODULE_AUTHOR("Wentong Wu <wentong.wu@intel.com>");293MODULE_AUTHOR("Zhifeng Wang <zhifeng.wang@intel.com>");294MODULE_AUTHOR("Lixu Zhang <lixu.zhang@intel.com>");295MODULE_DESCRIPTION("Intel La Jolla Cove Adapter USB-SPI driver");296MODULE_LICENSE("GPL");297MODULE_IMPORT_NS(LJCA);298