2 * Copyright (c) 2011-2016 Synaptics Incorporated
3 * Copyright (c) 2011 Unixphere
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 as published by
7 * the Free Software Foundation.
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/rmi.h>
13 #include <linux/slab.h>
14 #include <linux/spi/spi.h>
16 #include "rmi_driver.h"
18 #define RMI_SPI_DEFAULT_XFER_BUF_SIZE 64
20 #define RMI_PAGE_SELECT_REGISTER 0x00FF
21 #define RMI_SPI_PAGE(addr) (((addr) >> 8) & 0x80)
22 #define RMI_SPI_XFER_SIZE_LIMIT 255
24 #define BUFFER_SIZE_INCREMENT 32
29 RMI_SPI_V2_READ_UNIFIED,
30 RMI_SPI_V2_READ_SPLIT,
39 struct rmi_spi_xport {
40 struct rmi_transport_dev xport;
41 struct spi_device *spi;
43 struct mutex page_mutex;
50 struct spi_transfer *rx_xfers;
51 struct spi_transfer *tx_xfers;
56 static int rmi_spi_manage_pools(struct rmi_spi_xport *rmi_spi, int len)
58 struct spi_device *spi = rmi_spi->spi;
59 int buf_size = rmi_spi->xfer_buf_size
60 ? rmi_spi->xfer_buf_size : RMI_SPI_DEFAULT_XFER_BUF_SIZE;
61 struct spi_transfer *xfer_buf;
65 while (buf_size < len)
68 if (buf_size > RMI_SPI_XFER_SIZE_LIMIT)
69 buf_size = RMI_SPI_XFER_SIZE_LIMIT;
71 tmp = rmi_spi->rx_buf;
72 buf = devm_kzalloc(&spi->dev, buf_size * 2,
73 GFP_KERNEL | GFP_DMA);
77 rmi_spi->rx_buf = buf;
78 rmi_spi->tx_buf = &rmi_spi->rx_buf[buf_size];
79 rmi_spi->xfer_buf_size = buf_size;
82 devm_kfree(&spi->dev, tmp);
84 if (rmi_spi->xport.pdata.spi_data.read_delay_us)
85 rmi_spi->rx_xfer_count = buf_size;
87 rmi_spi->rx_xfer_count = 1;
89 if (rmi_spi->xport.pdata.spi_data.write_delay_us)
90 rmi_spi->tx_xfer_count = buf_size;
92 rmi_spi->tx_xfer_count = 1;
95 * Allocate a pool of spi_transfer buffers for devices which need
98 tmp = rmi_spi->rx_xfers;
99 xfer_buf = devm_kzalloc(&spi->dev,
100 (rmi_spi->rx_xfer_count + rmi_spi->tx_xfer_count)
101 * sizeof(struct spi_transfer), GFP_KERNEL);
105 rmi_spi->rx_xfers = xfer_buf;
106 rmi_spi->tx_xfers = &xfer_buf[rmi_spi->rx_xfer_count];
109 devm_kfree(&spi->dev, tmp);
114 static int rmi_spi_xfer(struct rmi_spi_xport *rmi_spi,
115 const struct rmi_spi_cmd *cmd, const u8 *tx_buf,
116 int tx_len, u8 *rx_buf, int rx_len)
118 struct spi_device *spi = rmi_spi->spi;
119 struct rmi_device_platform_data_spi *spi_data =
120 &rmi_spi->xport.pdata.spi_data;
121 struct spi_message msg;
122 struct spi_transfer *xfer;
128 u16 addr = cmd->addr;
130 spi_message_init(&msg);
137 case RMI_SPI_V2_READ_UNIFIED:
138 case RMI_SPI_V2_READ_SPLIT:
139 case RMI_SPI_V2_WRITE:
144 total_tx_len = cmd_len + tx_len;
145 len = max(total_tx_len, rx_len);
147 if (len > RMI_SPI_XFER_SIZE_LIMIT)
150 if (rmi_spi->xfer_buf_size < len)
151 rmi_spi_manage_pools(rmi_spi, len);
155 * SPI needs an address. Use 0x7FF if we want to keep
156 * reading from the last position of the register pointer.
162 rmi_spi->tx_buf[0] = (addr >> 8);
163 rmi_spi->tx_buf[1] = addr & 0xFF;
166 rmi_spi->tx_buf[0] = (addr >> 8) | 0x80;
167 rmi_spi->tx_buf[1] = addr & 0xFF;
169 case RMI_SPI_V2_READ_UNIFIED:
171 case RMI_SPI_V2_READ_SPLIT:
173 case RMI_SPI_V2_WRITE:
174 rmi_spi->tx_buf[0] = 0x40;
175 rmi_spi->tx_buf[1] = (addr >> 8) & 0xFF;
176 rmi_spi->tx_buf[2] = addr & 0xFF;
177 rmi_spi->tx_buf[3] = tx_len;
182 memcpy(&rmi_spi->tx_buf[cmd_len], tx_buf, tx_len);
184 if (rmi_spi->tx_xfer_count > 1) {
185 for (i = 0; i < total_tx_len; i++) {
186 xfer = &rmi_spi->tx_xfers[i];
187 memset(xfer, 0, sizeof(struct spi_transfer));
188 xfer->tx_buf = &rmi_spi->tx_buf[i];
190 xfer->delay_usecs = spi_data->write_delay_us;
191 spi_message_add_tail(xfer, &msg);
194 xfer = rmi_spi->tx_xfers;
195 memset(xfer, 0, sizeof(struct spi_transfer));
196 xfer->tx_buf = rmi_spi->tx_buf;
197 xfer->len = total_tx_len;
198 spi_message_add_tail(xfer, &msg);
201 rmi_dbg(RMI_DEBUG_XPORT, &spi->dev, "%s: cmd: %s tx_buf len: %d tx_buf: %*ph\n",
202 __func__, cmd->op == RMI_SPI_WRITE ? "WRITE" : "READ",
203 total_tx_len, total_tx_len, rmi_spi->tx_buf);
206 if (rmi_spi->rx_xfer_count > 1) {
207 for (i = 0; i < rx_len; i++) {
208 xfer = &rmi_spi->rx_xfers[i];
209 memset(xfer, 0, sizeof(struct spi_transfer));
210 xfer->rx_buf = &rmi_spi->rx_buf[i];
212 xfer->delay_usecs = spi_data->read_delay_us;
213 spi_message_add_tail(xfer, &msg);
216 xfer = rmi_spi->rx_xfers;
217 memset(xfer, 0, sizeof(struct spi_transfer));
218 xfer->rx_buf = rmi_spi->rx_buf;
220 spi_message_add_tail(xfer, &msg);
224 ret = spi_sync(spi, &msg);
226 dev_err(&spi->dev, "spi xfer failed: %d\n", ret);
231 memcpy(rx_buf, rmi_spi->rx_buf, rx_len);
232 rmi_dbg(RMI_DEBUG_XPORT, &spi->dev, "%s: (%d) %*ph\n",
233 __func__, rx_len, rx_len, rx_buf);
240 * rmi_set_page - Set RMI page
241 * @xport: The pointer to the rmi_transport_dev struct
242 * @page: The new page address.
244 * RMI devices have 16-bit addressing, but some of the transport
245 * implementations (like SMBus) only have 8-bit addressing. So RMI implements
246 * a page address at 0xff of every page so we can reliable page addresses
247 * every 256 registers.
249 * The page_mutex lock must be held when this function is entered.
251 * Returns zero on success, non-zero on failure.
253 static int rmi_set_page(struct rmi_spi_xport *rmi_spi, u8 page)
255 struct rmi_spi_cmd cmd;
258 cmd.op = RMI_SPI_WRITE;
259 cmd.addr = RMI_PAGE_SELECT_REGISTER;
261 ret = rmi_spi_xfer(rmi_spi, &cmd, &page, 1, NULL, 0);
264 rmi_spi->page = page;
269 static int rmi_spi_write_block(struct rmi_transport_dev *xport, u16 addr,
270 const void *buf, size_t len)
272 struct rmi_spi_xport *rmi_spi =
273 container_of(xport, struct rmi_spi_xport, xport);
274 struct rmi_spi_cmd cmd;
277 mutex_lock(&rmi_spi->page_mutex);
279 if (RMI_SPI_PAGE(addr) != rmi_spi->page) {
280 ret = rmi_set_page(rmi_spi, RMI_SPI_PAGE(addr));
285 cmd.op = RMI_SPI_WRITE;
288 ret = rmi_spi_xfer(rmi_spi, &cmd, buf, len, NULL, 0);
291 mutex_unlock(&rmi_spi->page_mutex);
295 static int rmi_spi_read_block(struct rmi_transport_dev *xport, u16 addr,
296 void *buf, size_t len)
298 struct rmi_spi_xport *rmi_spi =
299 container_of(xport, struct rmi_spi_xport, xport);
300 struct rmi_spi_cmd cmd;
303 mutex_lock(&rmi_spi->page_mutex);
305 if (RMI_SPI_PAGE(addr) != rmi_spi->page) {
306 ret = rmi_set_page(rmi_spi, RMI_SPI_PAGE(addr));
311 cmd.op = RMI_SPI_READ;
314 ret = rmi_spi_xfer(rmi_spi, &cmd, NULL, 0, buf, len);
317 mutex_unlock(&rmi_spi->page_mutex);
321 static const struct rmi_transport_ops rmi_spi_ops = {
322 .write_block = rmi_spi_write_block,
323 .read_block = rmi_spi_read_block,
327 static int rmi_spi_of_probe(struct spi_device *spi,
328 struct rmi_device_platform_data *pdata)
330 struct device *dev = &spi->dev;
333 retval = rmi_of_property_read_u32(dev,
334 &pdata->spi_data.read_delay_us,
335 "spi-rx-delay-us", 1);
339 retval = rmi_of_property_read_u32(dev,
340 &pdata->spi_data.write_delay_us,
341 "spi-tx-delay-us", 1);
348 static const struct of_device_id rmi_spi_of_match[] = {
349 { .compatible = "syna,rmi4-spi" },
352 MODULE_DEVICE_TABLE(of, rmi_spi_of_match);
354 static inline int rmi_spi_of_probe(struct spi_device *spi,
355 struct rmi_device_platform_data *pdata)
361 static void rmi_spi_unregister_transport(void *data)
363 struct rmi_spi_xport *rmi_spi = data;
365 rmi_unregister_transport_device(&rmi_spi->xport);
368 static int rmi_spi_probe(struct spi_device *spi)
370 struct rmi_spi_xport *rmi_spi;
371 struct rmi_device_platform_data *pdata;
372 struct rmi_device_platform_data *spi_pdata = spi->dev.platform_data;
375 if (spi->master->flags & SPI_MASTER_HALF_DUPLEX)
378 rmi_spi = devm_kzalloc(&spi->dev, sizeof(struct rmi_spi_xport),
383 pdata = &rmi_spi->xport.pdata;
385 if (spi->dev.of_node) {
386 retval = rmi_spi_of_probe(spi, pdata);
389 } else if (spi_pdata) {
393 if (pdata->spi_data.bits_per_word)
394 spi->bits_per_word = pdata->spi_data.bits_per_word;
396 if (pdata->spi_data.mode)
397 spi->mode = pdata->spi_data.mode;
399 retval = spi_setup(spi);
401 dev_err(&spi->dev, "spi_setup failed!\n");
405 pdata->irq = spi->irq;
408 mutex_init(&rmi_spi->page_mutex);
410 rmi_spi->xport.dev = &spi->dev;
411 rmi_spi->xport.proto_name = "spi";
412 rmi_spi->xport.ops = &rmi_spi_ops;
414 spi_set_drvdata(spi, rmi_spi);
416 retval = rmi_spi_manage_pools(rmi_spi, RMI_SPI_DEFAULT_XFER_BUF_SIZE);
421 * Setting the page to zero will (a) make sure the PSR is in a
422 * known state, and (b) make sure we can talk to the device.
424 retval = rmi_set_page(rmi_spi, 0);
426 dev_err(&spi->dev, "Failed to set page select to 0.\n");
430 retval = rmi_register_transport_device(&rmi_spi->xport);
432 dev_err(&spi->dev, "failed to register transport.\n");
435 retval = devm_add_action_or_reset(&spi->dev,
436 rmi_spi_unregister_transport,
441 dev_info(&spi->dev, "registered RMI SPI driver\n");
445 #ifdef CONFIG_PM_SLEEP
446 static int rmi_spi_suspend(struct device *dev)
448 struct spi_device *spi = to_spi_device(dev);
449 struct rmi_spi_xport *rmi_spi = spi_get_drvdata(spi);
452 ret = rmi_driver_suspend(rmi_spi->xport.rmi_dev, true);
454 dev_warn(dev, "Failed to resume device: %d\n", ret);
459 static int rmi_spi_resume(struct device *dev)
461 struct spi_device *spi = to_spi_device(dev);
462 struct rmi_spi_xport *rmi_spi = spi_get_drvdata(spi);
465 ret = rmi_driver_resume(rmi_spi->xport.rmi_dev, true);
467 dev_warn(dev, "Failed to resume device: %d\n", ret);
474 static int rmi_spi_runtime_suspend(struct device *dev)
476 struct spi_device *spi = to_spi_device(dev);
477 struct rmi_spi_xport *rmi_spi = spi_get_drvdata(spi);
480 ret = rmi_driver_suspend(rmi_spi->xport.rmi_dev, false);
482 dev_warn(dev, "Failed to resume device: %d\n", ret);
487 static int rmi_spi_runtime_resume(struct device *dev)
489 struct spi_device *spi = to_spi_device(dev);
490 struct rmi_spi_xport *rmi_spi = spi_get_drvdata(spi);
493 ret = rmi_driver_resume(rmi_spi->xport.rmi_dev, false);
495 dev_warn(dev, "Failed to resume device: %d\n", ret);
501 static const struct dev_pm_ops rmi_spi_pm = {
502 SET_SYSTEM_SLEEP_PM_OPS(rmi_spi_suspend, rmi_spi_resume)
503 SET_RUNTIME_PM_OPS(rmi_spi_runtime_suspend, rmi_spi_runtime_resume,
507 static const struct spi_device_id rmi_id[] = {
511 MODULE_DEVICE_TABLE(spi, rmi_id);
513 static struct spi_driver rmi_spi_driver = {
517 .of_match_table = of_match_ptr(rmi_spi_of_match),
520 .probe = rmi_spi_probe,
523 module_spi_driver(rmi_spi_driver);
525 MODULE_AUTHOR("Christopher Heiny <cheiny@synaptics.com>");
526 MODULE_AUTHOR("Andrew Duggan <aduggan@synaptics.com>");
527 MODULE_DESCRIPTION("RMI SPI driver");
528 MODULE_LICENSE("GPL");
529 MODULE_VERSION(RMI_DRIVER_VERSION);