![Dmitry Torokhov](/assets/img/avatar_default.png)
We are not registering drivers, but transport devices (AKA sensors), so let's call them that. Also let's rename "retval" to "error" in probe() functions as the variables are used to store error codes. Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
532 lines
12 KiB
C
532 lines
12 KiB
C
/*
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* Copyright (c) 2011-2016 Synaptics Incorporated
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* Copyright (c) 2011 Unixphere
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/rmi.h>
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#include <linux/slab.h>
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#include <linux/spi/spi.h>
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#include <linux/of.h>
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#include "rmi_driver.h"
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#define RMI_SPI_DEFAULT_XFER_BUF_SIZE 64
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#define RMI_PAGE_SELECT_REGISTER 0x00FF
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#define RMI_SPI_PAGE(addr) (((addr) >> 8) & 0x80)
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#define RMI_SPI_XFER_SIZE_LIMIT 255
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#define BUFFER_SIZE_INCREMENT 32
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enum rmi_spi_op {
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RMI_SPI_WRITE = 0,
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RMI_SPI_READ,
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RMI_SPI_V2_READ_UNIFIED,
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RMI_SPI_V2_READ_SPLIT,
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RMI_SPI_V2_WRITE,
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};
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struct rmi_spi_cmd {
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enum rmi_spi_op op;
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u16 addr;
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};
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struct rmi_spi_xport {
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struct rmi_transport_dev xport;
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struct spi_device *spi;
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struct mutex page_mutex;
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int page;
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u8 *rx_buf;
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u8 *tx_buf;
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int xfer_buf_size;
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struct spi_transfer *rx_xfers;
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struct spi_transfer *tx_xfers;
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int rx_xfer_count;
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int tx_xfer_count;
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};
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static int rmi_spi_manage_pools(struct rmi_spi_xport *rmi_spi, int len)
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{
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struct spi_device *spi = rmi_spi->spi;
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int buf_size = rmi_spi->xfer_buf_size
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? rmi_spi->xfer_buf_size : RMI_SPI_DEFAULT_XFER_BUF_SIZE;
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struct spi_transfer *xfer_buf;
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void *buf;
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void *tmp;
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while (buf_size < len)
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buf_size *= 2;
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if (buf_size > RMI_SPI_XFER_SIZE_LIMIT)
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buf_size = RMI_SPI_XFER_SIZE_LIMIT;
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tmp = rmi_spi->rx_buf;
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buf = devm_kzalloc(&spi->dev, buf_size * 2,
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GFP_KERNEL | GFP_DMA);
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if (!buf)
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return -ENOMEM;
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rmi_spi->rx_buf = buf;
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rmi_spi->tx_buf = &rmi_spi->rx_buf[buf_size];
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rmi_spi->xfer_buf_size = buf_size;
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if (tmp)
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devm_kfree(&spi->dev, tmp);
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if (rmi_spi->xport.pdata.spi_data.read_delay_us)
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rmi_spi->rx_xfer_count = buf_size;
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else
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rmi_spi->rx_xfer_count = 1;
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if (rmi_spi->xport.pdata.spi_data.write_delay_us)
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rmi_spi->tx_xfer_count = buf_size;
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else
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rmi_spi->tx_xfer_count = 1;
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/*
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* Allocate a pool of spi_transfer buffers for devices which need
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* per byte delays.
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*/
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tmp = rmi_spi->rx_xfers;
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xfer_buf = devm_kzalloc(&spi->dev,
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(rmi_spi->rx_xfer_count + rmi_spi->tx_xfer_count)
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* sizeof(struct spi_transfer), GFP_KERNEL);
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if (!xfer_buf)
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return -ENOMEM;
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rmi_spi->rx_xfers = xfer_buf;
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rmi_spi->tx_xfers = &xfer_buf[rmi_spi->rx_xfer_count];
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if (tmp)
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devm_kfree(&spi->dev, tmp);
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return 0;
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}
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static int rmi_spi_xfer(struct rmi_spi_xport *rmi_spi,
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const struct rmi_spi_cmd *cmd, const u8 *tx_buf,
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int tx_len, u8 *rx_buf, int rx_len)
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{
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struct spi_device *spi = rmi_spi->spi;
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struct rmi_device_platform_data_spi *spi_data =
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&rmi_spi->xport.pdata.spi_data;
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struct spi_message msg;
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struct spi_transfer *xfer;
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int ret = 0;
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int len;
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int cmd_len = 0;
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int total_tx_len;
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int i;
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u16 addr = cmd->addr;
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spi_message_init(&msg);
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switch (cmd->op) {
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case RMI_SPI_WRITE:
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case RMI_SPI_READ:
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cmd_len += 2;
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break;
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case RMI_SPI_V2_READ_UNIFIED:
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case RMI_SPI_V2_READ_SPLIT:
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case RMI_SPI_V2_WRITE:
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cmd_len += 4;
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break;
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}
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total_tx_len = cmd_len + tx_len;
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len = max(total_tx_len, rx_len);
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if (len > RMI_SPI_XFER_SIZE_LIMIT)
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return -EINVAL;
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if (rmi_spi->xfer_buf_size < len)
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rmi_spi_manage_pools(rmi_spi, len);
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if (addr == 0)
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/*
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* SPI needs an address. Use 0x7FF if we want to keep
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* reading from the last position of the register pointer.
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*/
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addr = 0x7FF;
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switch (cmd->op) {
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case RMI_SPI_WRITE:
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rmi_spi->tx_buf[0] = (addr >> 8);
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rmi_spi->tx_buf[1] = addr & 0xFF;
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break;
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case RMI_SPI_READ:
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rmi_spi->tx_buf[0] = (addr >> 8) | 0x80;
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rmi_spi->tx_buf[1] = addr & 0xFF;
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break;
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case RMI_SPI_V2_READ_UNIFIED:
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break;
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case RMI_SPI_V2_READ_SPLIT:
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break;
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case RMI_SPI_V2_WRITE:
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rmi_spi->tx_buf[0] = 0x40;
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rmi_spi->tx_buf[1] = (addr >> 8) & 0xFF;
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rmi_spi->tx_buf[2] = addr & 0xFF;
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rmi_spi->tx_buf[3] = tx_len;
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break;
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}
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if (tx_buf)
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memcpy(&rmi_spi->tx_buf[cmd_len], tx_buf, tx_len);
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if (rmi_spi->tx_xfer_count > 1) {
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for (i = 0; i < total_tx_len; i++) {
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xfer = &rmi_spi->tx_xfers[i];
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memset(xfer, 0, sizeof(struct spi_transfer));
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xfer->tx_buf = &rmi_spi->tx_buf[i];
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xfer->len = 1;
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xfer->delay_usecs = spi_data->write_delay_us;
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spi_message_add_tail(xfer, &msg);
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}
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} else {
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xfer = rmi_spi->tx_xfers;
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memset(xfer, 0, sizeof(struct spi_transfer));
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xfer->tx_buf = rmi_spi->tx_buf;
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xfer->len = total_tx_len;
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spi_message_add_tail(xfer, &msg);
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}
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rmi_dbg(RMI_DEBUG_XPORT, &spi->dev, "%s: cmd: %s tx_buf len: %d tx_buf: %*ph\n",
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__func__, cmd->op == RMI_SPI_WRITE ? "WRITE" : "READ",
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total_tx_len, total_tx_len, rmi_spi->tx_buf);
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if (rx_buf) {
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if (rmi_spi->rx_xfer_count > 1) {
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for (i = 0; i < rx_len; i++) {
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xfer = &rmi_spi->rx_xfers[i];
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memset(xfer, 0, sizeof(struct spi_transfer));
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xfer->rx_buf = &rmi_spi->rx_buf[i];
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xfer->len = 1;
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xfer->delay_usecs = spi_data->read_delay_us;
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spi_message_add_tail(xfer, &msg);
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}
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} else {
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xfer = rmi_spi->rx_xfers;
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memset(xfer, 0, sizeof(struct spi_transfer));
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xfer->rx_buf = rmi_spi->rx_buf;
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xfer->len = rx_len;
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spi_message_add_tail(xfer, &msg);
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}
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}
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ret = spi_sync(spi, &msg);
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if (ret < 0) {
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dev_err(&spi->dev, "spi xfer failed: %d\n", ret);
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return ret;
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}
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if (rx_buf) {
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memcpy(rx_buf, rmi_spi->rx_buf, rx_len);
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rmi_dbg(RMI_DEBUG_XPORT, &spi->dev, "%s: (%d) %*ph\n",
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__func__, rx_len, rx_len, rx_buf);
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}
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return 0;
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}
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/*
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* rmi_set_page - Set RMI page
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* @xport: The pointer to the rmi_transport_dev struct
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* @page: The new page address.
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*
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* RMI devices have 16-bit addressing, but some of the transport
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* implementations (like SMBus) only have 8-bit addressing. So RMI implements
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* a page address at 0xff of every page so we can reliable page addresses
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* every 256 registers.
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*
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* The page_mutex lock must be held when this function is entered.
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*
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* Returns zero on success, non-zero on failure.
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*/
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static int rmi_set_page(struct rmi_spi_xport *rmi_spi, u8 page)
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{
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struct rmi_spi_cmd cmd;
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int ret;
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cmd.op = RMI_SPI_WRITE;
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cmd.addr = RMI_PAGE_SELECT_REGISTER;
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ret = rmi_spi_xfer(rmi_spi, &cmd, &page, 1, NULL, 0);
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if (ret)
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rmi_spi->page = page;
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return ret;
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}
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static int rmi_spi_write_block(struct rmi_transport_dev *xport, u16 addr,
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const void *buf, size_t len)
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{
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struct rmi_spi_xport *rmi_spi =
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container_of(xport, struct rmi_spi_xport, xport);
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struct rmi_spi_cmd cmd;
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int ret;
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mutex_lock(&rmi_spi->page_mutex);
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if (RMI_SPI_PAGE(addr) != rmi_spi->page) {
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ret = rmi_set_page(rmi_spi, RMI_SPI_PAGE(addr));
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if (ret)
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goto exit;
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}
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cmd.op = RMI_SPI_WRITE;
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cmd.addr = addr;
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ret = rmi_spi_xfer(rmi_spi, &cmd, buf, len, NULL, 0);
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exit:
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mutex_unlock(&rmi_spi->page_mutex);
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return ret;
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}
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static int rmi_spi_read_block(struct rmi_transport_dev *xport, u16 addr,
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void *buf, size_t len)
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{
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struct rmi_spi_xport *rmi_spi =
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container_of(xport, struct rmi_spi_xport, xport);
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struct rmi_spi_cmd cmd;
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int ret;
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mutex_lock(&rmi_spi->page_mutex);
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if (RMI_SPI_PAGE(addr) != rmi_spi->page) {
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ret = rmi_set_page(rmi_spi, RMI_SPI_PAGE(addr));
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if (ret)
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goto exit;
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}
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cmd.op = RMI_SPI_READ;
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cmd.addr = addr;
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ret = rmi_spi_xfer(rmi_spi, &cmd, NULL, 0, buf, len);
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exit:
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mutex_unlock(&rmi_spi->page_mutex);
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return ret;
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}
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static const struct rmi_transport_ops rmi_spi_ops = {
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.write_block = rmi_spi_write_block,
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.read_block = rmi_spi_read_block,
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};
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#ifdef CONFIG_OF
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static int rmi_spi_of_probe(struct spi_device *spi,
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struct rmi_device_platform_data *pdata)
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{
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struct device *dev = &spi->dev;
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int retval;
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retval = rmi_of_property_read_u32(dev,
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&pdata->spi_data.read_delay_us,
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"spi-rx-delay-us", 1);
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if (retval)
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return retval;
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retval = rmi_of_property_read_u32(dev,
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&pdata->spi_data.write_delay_us,
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"spi-tx-delay-us", 1);
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if (retval)
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return retval;
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return 0;
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}
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static const struct of_device_id rmi_spi_of_match[] = {
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{ .compatible = "syna,rmi4-spi" },
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{},
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};
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MODULE_DEVICE_TABLE(of, rmi_spi_of_match);
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#else
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static inline int rmi_spi_of_probe(struct spi_device *spi,
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struct rmi_device_platform_data *pdata)
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{
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return -ENODEV;
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}
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#endif
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static void rmi_spi_unregister_transport(void *data)
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{
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struct rmi_spi_xport *rmi_spi = data;
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rmi_unregister_transport_device(&rmi_spi->xport);
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}
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static int rmi_spi_probe(struct spi_device *spi)
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{
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struct rmi_spi_xport *rmi_spi;
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struct rmi_device_platform_data *pdata;
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struct rmi_device_platform_data *spi_pdata = spi->dev.platform_data;
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int error;
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if (spi->master->flags & SPI_MASTER_HALF_DUPLEX)
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return -EINVAL;
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rmi_spi = devm_kzalloc(&spi->dev, sizeof(struct rmi_spi_xport),
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GFP_KERNEL);
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if (!rmi_spi)
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return -ENOMEM;
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pdata = &rmi_spi->xport.pdata;
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if (spi->dev.of_node) {
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error = rmi_spi_of_probe(spi, pdata);
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if (error)
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return error;
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} else if (spi_pdata) {
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*pdata = *spi_pdata;
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}
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if (pdata->spi_data.bits_per_word)
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spi->bits_per_word = pdata->spi_data.bits_per_word;
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if (pdata->spi_data.mode)
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spi->mode = pdata->spi_data.mode;
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error = spi_setup(spi);
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if (error < 0) {
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dev_err(&spi->dev, "spi_setup failed!\n");
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return error;
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}
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pdata->irq = spi->irq;
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rmi_spi->spi = spi;
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mutex_init(&rmi_spi->page_mutex);
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rmi_spi->xport.dev = &spi->dev;
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rmi_spi->xport.proto_name = "spi";
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rmi_spi->xport.ops = &rmi_spi_ops;
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spi_set_drvdata(spi, rmi_spi);
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error = rmi_spi_manage_pools(rmi_spi, RMI_SPI_DEFAULT_XFER_BUF_SIZE);
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if (error)
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return error;
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/*
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* Setting the page to zero will (a) make sure the PSR is in a
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* known state, and (b) make sure we can talk to the device.
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*/
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error = rmi_set_page(rmi_spi, 0);
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if (error) {
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dev_err(&spi->dev, "Failed to set page select to 0.\n");
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return error;
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}
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dev_info(&spi->dev, "registering SPI-connected sensor\n");
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error = rmi_register_transport_device(&rmi_spi->xport);
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if (error) {
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dev_err(&spi->dev, "failed to register sensor: %d\n", error);
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return error;
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}
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error = devm_add_action_or_reset(&spi->dev,
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rmi_spi_unregister_transport,
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rmi_spi);
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if (error)
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return error;
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return 0;
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}
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#ifdef CONFIG_PM_SLEEP
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static int rmi_spi_suspend(struct device *dev)
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{
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struct spi_device *spi = to_spi_device(dev);
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struct rmi_spi_xport *rmi_spi = spi_get_drvdata(spi);
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int ret;
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ret = rmi_driver_suspend(rmi_spi->xport.rmi_dev, true);
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if (ret)
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dev_warn(dev, "Failed to resume device: %d\n", ret);
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return ret;
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}
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static int rmi_spi_resume(struct device *dev)
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{
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struct spi_device *spi = to_spi_device(dev);
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struct rmi_spi_xport *rmi_spi = spi_get_drvdata(spi);
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int ret;
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ret = rmi_driver_resume(rmi_spi->xport.rmi_dev, true);
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if (ret)
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dev_warn(dev, "Failed to resume device: %d\n", ret);
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return ret;
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}
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#endif
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#ifdef CONFIG_PM
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static int rmi_spi_runtime_suspend(struct device *dev)
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{
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struct spi_device *spi = to_spi_device(dev);
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struct rmi_spi_xport *rmi_spi = spi_get_drvdata(spi);
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int ret;
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ret = rmi_driver_suspend(rmi_spi->xport.rmi_dev, false);
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if (ret)
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dev_warn(dev, "Failed to resume device: %d\n", ret);
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return 0;
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}
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static int rmi_spi_runtime_resume(struct device *dev)
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{
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struct spi_device *spi = to_spi_device(dev);
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struct rmi_spi_xport *rmi_spi = spi_get_drvdata(spi);
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int ret;
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ret = rmi_driver_resume(rmi_spi->xport.rmi_dev, false);
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if (ret)
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dev_warn(dev, "Failed to resume device: %d\n", ret);
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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,
|
|
.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");
|
|
MODULE_VERSION(RMI_DRIVER_VERSION);
|