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path: root/drivers/input/rmi4/rmi_spi.c
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Diffstat (limited to 'drivers/input/rmi4/rmi_spi.c')
-rw-r--r--drivers/input/rmi4/rmi_spi.c528
1 files changed, 528 insertions, 0 deletions
diff --git a/drivers/input/rmi4/rmi_spi.c b/drivers/input/rmi4/rmi_spi.c
new file mode 100644
index 0000000000..852aeb0b2c
--- /dev/null
+++ b/drivers/input/rmi4/rmi_spi.c
@@ -0,0 +1,528 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2011-2016 Synaptics Incorporated
+ * Copyright (c) 2011 Unixphere
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/rmi.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+#include <linux/of.h>
+#include "rmi_driver.h"
+
+#define RMI_SPI_DEFAULT_XFER_BUF_SIZE 64
+
+#define RMI_PAGE_SELECT_REGISTER 0x00FF
+#define RMI_SPI_PAGE(addr) (((addr) >> 8) & 0x80)
+#define RMI_SPI_XFER_SIZE_LIMIT 255
+
+#define BUFFER_SIZE_INCREMENT 32
+
+enum rmi_spi_op {
+ RMI_SPI_WRITE = 0,
+ RMI_SPI_READ,
+ RMI_SPI_V2_READ_UNIFIED,
+ RMI_SPI_V2_READ_SPLIT,
+ RMI_SPI_V2_WRITE,
+};
+
+struct rmi_spi_cmd {
+ enum rmi_spi_op op;
+ u16 addr;
+};
+
+struct rmi_spi_xport {
+ struct rmi_transport_dev xport;
+ struct spi_device *spi;
+
+ struct mutex page_mutex;
+ int page;
+
+ u8 *rx_buf;
+ u8 *tx_buf;
+ int xfer_buf_size;
+
+ struct spi_transfer *rx_xfers;
+ struct spi_transfer *tx_xfers;
+ int rx_xfer_count;
+ int tx_xfer_count;
+};
+
+static int rmi_spi_manage_pools(struct rmi_spi_xport *rmi_spi, int len)
+{
+ struct spi_device *spi = rmi_spi->spi;
+ int buf_size = rmi_spi->xfer_buf_size
+ ? rmi_spi->xfer_buf_size : RMI_SPI_DEFAULT_XFER_BUF_SIZE;
+ struct spi_transfer *xfer_buf;
+ void *buf;
+ void *tmp;
+
+ while (buf_size < len)
+ buf_size *= 2;
+
+ if (buf_size > RMI_SPI_XFER_SIZE_LIMIT)
+ buf_size = RMI_SPI_XFER_SIZE_LIMIT;
+
+ tmp = rmi_spi->rx_buf;
+ buf = devm_kcalloc(&spi->dev, buf_size, 2,
+ GFP_KERNEL | GFP_DMA);
+ if (!buf)
+ return -ENOMEM;
+
+ rmi_spi->rx_buf = buf;
+ rmi_spi->tx_buf = &rmi_spi->rx_buf[buf_size];
+ rmi_spi->xfer_buf_size = buf_size;
+
+ if (tmp)
+ devm_kfree(&spi->dev, tmp);
+
+ if (rmi_spi->xport.pdata.spi_data.read_delay_us)
+ rmi_spi->rx_xfer_count = buf_size;
+ else
+ rmi_spi->rx_xfer_count = 1;
+
+ if (rmi_spi->xport.pdata.spi_data.write_delay_us)
+ rmi_spi->tx_xfer_count = buf_size;
+ else
+ rmi_spi->tx_xfer_count = 1;
+
+ /*
+ * Allocate a pool of spi_transfer buffers for devices which need
+ * per byte delays.
+ */
+ tmp = rmi_spi->rx_xfers;
+ xfer_buf = devm_kcalloc(&spi->dev,
+ rmi_spi->rx_xfer_count + rmi_spi->tx_xfer_count,
+ sizeof(struct spi_transfer),
+ GFP_KERNEL);
+ if (!xfer_buf)
+ return -ENOMEM;
+
+ rmi_spi->rx_xfers = xfer_buf;
+ rmi_spi->tx_xfers = &xfer_buf[rmi_spi->rx_xfer_count];
+
+ if (tmp)
+ devm_kfree(&spi->dev, tmp);
+
+ return 0;
+}
+
+static int rmi_spi_xfer(struct rmi_spi_xport *rmi_spi,
+ const struct rmi_spi_cmd *cmd, const u8 *tx_buf,
+ int tx_len, u8 *rx_buf, int rx_len)
+{
+ struct spi_device *spi = rmi_spi->spi;
+ struct rmi_device_platform_data_spi *spi_data =
+ &rmi_spi->xport.pdata.spi_data;
+ struct spi_message msg;
+ struct spi_transfer *xfer;
+ int ret = 0;
+ int len;
+ int cmd_len = 0;
+ int total_tx_len;
+ int i;
+ u16 addr = cmd->addr;
+
+ spi_message_init(&msg);
+
+ switch (cmd->op) {
+ case RMI_SPI_WRITE:
+ case RMI_SPI_READ:
+ cmd_len += 2;
+ break;
+ case RMI_SPI_V2_READ_UNIFIED:
+ case RMI_SPI_V2_READ_SPLIT:
+ case RMI_SPI_V2_WRITE:
+ cmd_len += 4;
+ break;
+ }
+
+ total_tx_len = cmd_len + tx_len;
+ len = max(total_tx_len, rx_len);
+
+ if (len > RMI_SPI_XFER_SIZE_LIMIT)
+ return -EINVAL;
+
+ if (rmi_spi->xfer_buf_size < len) {
+ ret = rmi_spi_manage_pools(rmi_spi, len);
+ if (ret < 0)
+ return ret;
+ }
+
+ if (addr == 0)
+ /*
+ * SPI needs an address. Use 0x7FF if we want to keep
+ * reading from the last position of the register pointer.
+ */
+ addr = 0x7FF;
+
+ switch (cmd->op) {
+ case RMI_SPI_WRITE:
+ rmi_spi->tx_buf[0] = (addr >> 8);
+ rmi_spi->tx_buf[1] = addr & 0xFF;
+ break;
+ case RMI_SPI_READ:
+ rmi_spi->tx_buf[0] = (addr >> 8) | 0x80;
+ rmi_spi->tx_buf[1] = addr & 0xFF;
+ break;
+ case RMI_SPI_V2_READ_UNIFIED:
+ break;
+ case RMI_SPI_V2_READ_SPLIT:
+ break;
+ case RMI_SPI_V2_WRITE:
+ rmi_spi->tx_buf[0] = 0x40;
+ rmi_spi->tx_buf[1] = (addr >> 8) & 0xFF;
+ rmi_spi->tx_buf[2] = addr & 0xFF;
+ rmi_spi->tx_buf[3] = tx_len;
+ break;
+ }
+
+ if (tx_buf)
+ memcpy(&rmi_spi->tx_buf[cmd_len], tx_buf, tx_len);
+
+ if (rmi_spi->tx_xfer_count > 1) {
+ for (i = 0; i < total_tx_len; i++) {
+ xfer = &rmi_spi->tx_xfers[i];
+ memset(xfer, 0, sizeof(struct spi_transfer));
+ xfer->tx_buf = &rmi_spi->tx_buf[i];
+ xfer->len = 1;
+ xfer->delay.value = spi_data->write_delay_us;
+ xfer->delay.unit = SPI_DELAY_UNIT_USECS;
+ spi_message_add_tail(xfer, &msg);
+ }
+ } else {
+ xfer = rmi_spi->tx_xfers;
+ memset(xfer, 0, sizeof(struct spi_transfer));
+ xfer->tx_buf = rmi_spi->tx_buf;
+ xfer->len = total_tx_len;
+ spi_message_add_tail(xfer, &msg);
+ }
+
+ rmi_dbg(RMI_DEBUG_XPORT, &spi->dev, "%s: cmd: %s tx_buf len: %d tx_buf: %*ph\n",
+ __func__, cmd->op == RMI_SPI_WRITE ? "WRITE" : "READ",
+ total_tx_len, total_tx_len, rmi_spi->tx_buf);
+
+ if (rx_buf) {
+ if (rmi_spi->rx_xfer_count > 1) {
+ for (i = 0; i < rx_len; i++) {
+ xfer = &rmi_spi->rx_xfers[i];
+ memset(xfer, 0, sizeof(struct spi_transfer));
+ xfer->rx_buf = &rmi_spi->rx_buf[i];
+ xfer->len = 1;
+ xfer->delay.value = spi_data->read_delay_us;
+ xfer->delay.unit = SPI_DELAY_UNIT_USECS;
+ spi_message_add_tail(xfer, &msg);
+ }
+ } else {
+ xfer = rmi_spi->rx_xfers;
+ memset(xfer, 0, sizeof(struct spi_transfer));
+ xfer->rx_buf = rmi_spi->rx_buf;
+ xfer->len = rx_len;
+ spi_message_add_tail(xfer, &msg);
+ }
+ }
+
+ ret = spi_sync(spi, &msg);
+ if (ret < 0) {
+ dev_err(&spi->dev, "spi xfer failed: %d\n", ret);
+ return ret;
+ }
+
+ if (rx_buf) {
+ memcpy(rx_buf, rmi_spi->rx_buf, rx_len);
+ rmi_dbg(RMI_DEBUG_XPORT, &spi->dev, "%s: (%d) %*ph\n",
+ __func__, rx_len, rx_len, rx_buf);
+ }
+
+ return 0;
+}
+
+/*
+ * rmi_set_page - Set RMI page
+ * @xport: The pointer to the rmi_transport_dev struct
+ * @page: The new page address.
+ *
+ * RMI devices have 16-bit addressing, but some of the transport
+ * implementations (like SMBus) only have 8-bit addressing. So RMI implements
+ * a page address at 0xff of every page so we can reliable page addresses
+ * every 256 registers.
+ *
+ * The page_mutex lock must be held when this function is entered.
+ *
+ * Returns zero on success, non-zero on failure.
+ */
+static int rmi_set_page(struct rmi_spi_xport *rmi_spi, u8 page)
+{
+ struct rmi_spi_cmd cmd;
+ int ret;
+
+ cmd.op = RMI_SPI_WRITE;
+ cmd.addr = RMI_PAGE_SELECT_REGISTER;
+
+ ret = rmi_spi_xfer(rmi_spi, &cmd, &page, 1, NULL, 0);
+
+ if (ret)
+ rmi_spi->page = page;
+
+ return ret;
+}
+
+static int rmi_spi_write_block(struct rmi_transport_dev *xport, u16 addr,
+ const void *buf, size_t len)
+{
+ struct rmi_spi_xport *rmi_spi =
+ container_of(xport, struct rmi_spi_xport, xport);
+ struct rmi_spi_cmd cmd;
+ int ret;
+
+ mutex_lock(&rmi_spi->page_mutex);
+
+ if (RMI_SPI_PAGE(addr) != rmi_spi->page) {
+ ret = rmi_set_page(rmi_spi, RMI_SPI_PAGE(addr));
+ if (ret)
+ goto exit;
+ }
+
+ cmd.op = RMI_SPI_WRITE;
+ cmd.addr = addr;
+
+ ret = rmi_spi_xfer(rmi_spi, &cmd, buf, len, NULL, 0);
+
+exit:
+ mutex_unlock(&rmi_spi->page_mutex);
+ return ret;
+}
+
+static int rmi_spi_read_block(struct rmi_transport_dev *xport, u16 addr,
+ void *buf, size_t len)
+{
+ struct rmi_spi_xport *rmi_spi =
+ container_of(xport, struct rmi_spi_xport, xport);
+ struct rmi_spi_cmd cmd;
+ int ret;
+
+ mutex_lock(&rmi_spi->page_mutex);
+
+ if (RMI_SPI_PAGE(addr) != rmi_spi->page) {
+ ret = rmi_set_page(rmi_spi, RMI_SPI_PAGE(addr));
+ if (ret)
+ goto exit;
+ }
+
+ cmd.op = RMI_SPI_READ;
+ cmd.addr = addr;
+
+ ret = rmi_spi_xfer(rmi_spi, &cmd, NULL, 0, buf, len);
+
+exit:
+ mutex_unlock(&rmi_spi->page_mutex);
+ return ret;
+}
+
+static const struct rmi_transport_ops rmi_spi_ops = {
+ .write_block = rmi_spi_write_block,
+ .read_block = rmi_spi_read_block,
+};
+
+#ifdef CONFIG_OF
+static int rmi_spi_of_probe(struct spi_device *spi,
+ struct rmi_device_platform_data *pdata)
+{
+ struct device *dev = &spi->dev;
+ int retval;
+
+ retval = rmi_of_property_read_u32(dev,
+ &pdata->spi_data.read_delay_us,
+ "spi-rx-delay-us", 1);
+ if (retval)
+ return retval;
+
+ retval = rmi_of_property_read_u32(dev,
+ &pdata->spi_data.write_delay_us,
+ "spi-tx-delay-us", 1);
+ if (retval)
+ return retval;
+
+ return 0;
+}
+
+static const struct of_device_id rmi_spi_of_match[] = {
+ { .compatible = "syna,rmi4-spi" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, rmi_spi_of_match);
+#else
+static inline int rmi_spi_of_probe(struct spi_device *spi,
+ struct rmi_device_platform_data *pdata)
+{
+ return -ENODEV;
+}
+#endif
+
+static void rmi_spi_unregister_transport(void *data)
+{
+ struct rmi_spi_xport *rmi_spi = data;
+
+ rmi_unregister_transport_device(&rmi_spi->xport);
+}
+
+static int rmi_spi_probe(struct spi_device *spi)
+{
+ struct rmi_spi_xport *rmi_spi;
+ struct rmi_device_platform_data *pdata;
+ struct rmi_device_platform_data *spi_pdata = spi->dev.platform_data;
+ int error;
+
+ if (spi->master->flags & SPI_MASTER_HALF_DUPLEX)
+ return -EINVAL;
+
+ rmi_spi = devm_kzalloc(&spi->dev, sizeof(struct rmi_spi_xport),
+ GFP_KERNEL);
+ if (!rmi_spi)
+ return -ENOMEM;
+
+ pdata = &rmi_spi->xport.pdata;
+
+ if (spi->dev.of_node) {
+ error = rmi_spi_of_probe(spi, pdata);
+ if (error)
+ return error;
+ } else if (spi_pdata) {
+ *pdata = *spi_pdata;
+ }
+
+ if (pdata->spi_data.bits_per_word)
+ spi->bits_per_word = pdata->spi_data.bits_per_word;
+
+ if (pdata->spi_data.mode)
+ spi->mode = pdata->spi_data.mode;
+
+ error = spi_setup(spi);
+ if (error < 0) {
+ dev_err(&spi->dev, "spi_setup failed!\n");
+ return error;
+ }
+
+ pdata->irq = spi->irq;
+
+ rmi_spi->spi = spi;
+ mutex_init(&rmi_spi->page_mutex);
+
+ rmi_spi->xport.dev = &spi->dev;
+ rmi_spi->xport.proto_name = "spi";
+ rmi_spi->xport.ops = &rmi_spi_ops;
+
+ spi_set_drvdata(spi, rmi_spi);
+
+ error = rmi_spi_manage_pools(rmi_spi, RMI_SPI_DEFAULT_XFER_BUF_SIZE);
+ if (error)
+ return error;
+
+ /*
+ * Setting the page to zero will (a) make sure the PSR is in a
+ * known state, and (b) make sure we can talk to the device.
+ */
+ error = rmi_set_page(rmi_spi, 0);
+ if (error) {
+ dev_err(&spi->dev, "Failed to set page select to 0.\n");
+ return error;
+ }
+
+ dev_info(&spi->dev, "registering SPI-connected sensor\n");
+
+ error = rmi_register_transport_device(&rmi_spi->xport);
+ if (error) {
+ dev_err(&spi->dev, "failed to register sensor: %d\n", error);
+ return error;
+ }
+
+ error = devm_add_action_or_reset(&spi->dev,
+ rmi_spi_unregister_transport,
+ rmi_spi);
+ if (error)
+ return error;
+
+ return 0;
+}
+
+static int rmi_spi_suspend(struct device *dev)
+{
+ struct spi_device *spi = to_spi_device(dev);
+ struct rmi_spi_xport *rmi_spi = spi_get_drvdata(spi);
+ int ret;
+
+ ret = rmi_driver_suspend(rmi_spi->xport.rmi_dev, true);
+ if (ret)
+ dev_warn(dev, "Failed to resume device: %d\n", ret);
+
+ return ret;
+}
+
+static int rmi_spi_resume(struct device *dev)
+{
+ struct spi_device *spi = to_spi_device(dev);
+ struct rmi_spi_xport *rmi_spi = spi_get_drvdata(spi);
+ int ret;
+
+ ret = rmi_driver_resume(rmi_spi->xport.rmi_dev, true);
+ if (ret)
+ dev_warn(dev, "Failed to resume device: %d\n", ret);
+
+ return ret;
+}
+
+static int rmi_spi_runtime_suspend(struct device *dev)
+{
+ struct spi_device *spi = to_spi_device(dev);
+ struct rmi_spi_xport *rmi_spi = spi_get_drvdata(spi);
+ int ret;
+
+ ret = rmi_driver_suspend(rmi_spi->xport.rmi_dev, false);
+ if (ret)
+ dev_warn(dev, "Failed to resume device: %d\n", ret);
+
+ return 0;
+}
+
+static int rmi_spi_runtime_resume(struct device *dev)
+{
+ struct spi_device *spi = to_spi_device(dev);
+ struct rmi_spi_xport *rmi_spi = spi_get_drvdata(spi);
+ int ret;
+
+ ret = rmi_driver_resume(rmi_spi->xport.rmi_dev, false);
+ if (ret)
+ dev_warn(dev, "Failed to resume device: %d\n", ret);
+
+ return 0;
+}
+
+static const struct dev_pm_ops rmi_spi_pm = {
+ SYSTEM_SLEEP_PM_OPS(rmi_spi_suspend, rmi_spi_resume)
+ RUNTIME_PM_OPS(rmi_spi_runtime_suspend, rmi_spi_runtime_resume, NULL)
+};
+
+static const struct spi_device_id rmi_id[] = {
+ { "rmi4-spi", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, rmi_id);
+
+static struct spi_driver rmi_spi_driver = {
+ .driver = {
+ .name = "rmi4_spi",
+ .pm = pm_ptr(&rmi_spi_pm),
+ .of_match_table = of_match_ptr(rmi_spi_of_match),
+ },
+ .id_table = rmi_id,
+ .probe = rmi_spi_probe,
+};
+
+module_spi_driver(rmi_spi_driver);
+
+MODULE_AUTHOR("Christopher Heiny <cheiny@synaptics.com>");
+MODULE_AUTHOR("Andrew Duggan <aduggan@synaptics.com>");
+MODULE_DESCRIPTION("RMI SPI driver");
+MODULE_LICENSE("GPL");