--- /dev/null
+/*
+ * Copyright (c) 2011-2016 Synaptics Incorporated
+ * Copyright (c) 2011 Unixphere
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/rmi.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+#include <linux/irq.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;
+
+ int irq;
+
+ 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_kzalloc(&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_kzalloc(&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)
+ rmi_spi_manage_pools(rmi_spi, len);
+
+ 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_usecs = spi_data->write_delay_us;
+ 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_usecs = spi_data->read_delay_us;
+ 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,
+};
+
+static irqreturn_t rmi_spi_irq(int irq, void *dev_id)
+{
+ struct rmi_spi_xport *rmi_spi = dev_id;
+ struct rmi_device *rmi_dev = rmi_spi->xport.rmi_dev;
+ int ret;
+
+ ret = rmi_process_interrupt_requests(rmi_dev);
+ if (ret)
+ rmi_dbg(RMI_DEBUG_XPORT, &rmi_dev->dev,
+ "Failed to process interrupt request: %d\n", ret);
+
+ return IRQ_HANDLED;
+}
+
+static int rmi_spi_init_irq(struct spi_device *spi)
+{
+ struct rmi_spi_xport *rmi_spi = spi_get_drvdata(spi);
+ int irq_flags = irqd_get_trigger_type(irq_get_irq_data(rmi_spi->irq));
+ int ret;
+
+ if (!irq_flags)
+ irq_flags = IRQF_TRIGGER_LOW;
+
+ ret = devm_request_threaded_irq(&spi->dev, rmi_spi->irq, NULL,
+ rmi_spi_irq, irq_flags | IRQF_ONESHOT,
+ dev_name(&spi->dev), rmi_spi);
+ if (ret < 0) {
+ dev_warn(&spi->dev, "Failed to register interrupt %d\n",
+ rmi_spi->irq);
+ return ret;
+ }
+
+ return 0;
+}
+
+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 retval;
+
+ 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_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;
+
+ retval = spi_setup(spi);
+ if (retval < 0) {
+ dev_err(&spi->dev, "spi_setup failed!\n");
+ return retval;
+ }
+
+ if (spi->irq > 0)
+ rmi_spi->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);
+
+ retval = rmi_spi_manage_pools(rmi_spi, RMI_SPI_DEFAULT_XFER_BUF_SIZE);
+ if (retval)
+ return retval;
+
+ /*
+ * 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.
+ */
+ retval = rmi_set_page(rmi_spi, 0);
+ if (retval) {
+ dev_err(&spi->dev, "Failed to set page select to 0.\n");
+ return retval;
+ }
+
+ retval = rmi_register_transport_device(&rmi_spi->xport);
+ if (retval) {
+ dev_err(&spi->dev, "failed to register transport.\n");
+ return retval;
+ }
+
+ retval = rmi_spi_init_irq(spi);
+ if (retval < 0)
+ return retval;
+
+ dev_info(&spi->dev, "registered RMI SPI driver\n");
+ return 0;
+}
+
+static int rmi_spi_remove(struct spi_device *spi)
+{
+ struct rmi_spi_xport *rmi_spi = spi_get_drvdata(spi);
+
+ rmi_unregister_transport_device(&rmi_spi->xport);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+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);
+ if (ret)
+ dev_warn(dev, "Failed to resume device: %d\n", ret);
+
+ disable_irq(rmi_spi->irq);
+ if (device_may_wakeup(&spi->dev)) {
+ ret = enable_irq_wake(rmi_spi->irq);
+ if (!ret)
+ dev_warn(dev, "Failed to enable irq for wake: %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;
+
+ enable_irq(rmi_spi->irq);
+ if (device_may_wakeup(&spi->dev)) {
+ ret = disable_irq_wake(rmi_spi->irq);
+ if (!ret)
+ dev_warn(dev, "Failed to disable irq for wake: %d\n",
+ ret);
+ }
+
+ ret = rmi_driver_resume(rmi_spi->xport.rmi_dev);
+ if (ret)
+ dev_warn(dev, "Failed to resume device: %d\n", ret);
+
+ return ret;
+}
+#endif
+
+#ifdef CONFIG_PM
+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);
+ if (ret)
+ dev_warn(dev, "Failed to resume device: %d\n", ret);
+
+ disable_irq(rmi_spi->irq);
+
+ 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;
+
+ enable_irq(rmi_spi->irq);
+
+ ret = rmi_driver_resume(rmi_spi->xport.rmi_dev);
+ if (ret)
+ dev_warn(dev, "Failed to resume device: %d\n", ret);
+
+ return 0;
+}
+#endif
+
+static const struct dev_pm_ops rmi_spi_pm = {
+ SET_SYSTEM_SLEEP_PM_OPS(rmi_spi_suspend, rmi_spi_resume)
+ SET_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 = &rmi_spi_pm,
+ },
+ .id_table = rmi_id,
+ .probe = rmi_spi_probe,
+ .remove = rmi_spi_remove,
+};
+
+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");
+MODULE_VERSION(RMI_DRIVER_VERSION);
git.samba.org / sfrench / cifs-2.6.git / commitdiff