336 lines
8.3 KiB
C
336 lines
8.3 KiB
C
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/*
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* Synaptics DSX touchscreen driver
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*
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* Copyright (C) 2012 Synaptics Incorporated
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*
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* Copyright (C) 2012 Alexandra Chin <alexandra.chin@tw.synaptics.com>
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* Copyright (C) 2012 Scott Lin <scott.lin@tw.synaptics.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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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/slab.h>
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#include <linux/spi/spi.h>
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#include <linux/delay.h>
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#include <linux/input.h>
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#include <linux/types.h>
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#include <linux/platform_device.h>
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#include <linux/input/synaptics_dsx.h>
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#include "synaptics_dsx_core.h"
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#define SPI_READ 0x80
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#define SPI_WRITE 0x00
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static int synaptics_rmi4_spi_set_page(struct synaptics_rmi4_data *rmi4_data,
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unsigned short addr)
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{
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int retval;
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unsigned int index;
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unsigned int xfer_count = PAGE_SELECT_LEN + 1;
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unsigned char txbuf[xfer_count];
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unsigned char page;
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struct spi_message msg;
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struct spi_transfer xfers[xfer_count];
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struct spi_device *spi = to_spi_device(rmi4_data->pdev->dev.parent);
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const struct synaptics_dsx_board_data *bdata =
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rmi4_data->hw_if->board_data;
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page = ((addr >> 8) & ~MASK_7BIT);
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if (page != rmi4_data->current_page) {
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spi_message_init(&msg);
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txbuf[0] = SPI_WRITE;
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txbuf[1] = MASK_8BIT;
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txbuf[2] = page;
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for (index = 0; index < xfer_count; index++) {
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memset(&xfers[index], 0, sizeof(struct spi_transfer));
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xfers[index].len = 1;
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xfers[index].delay_usecs = bdata->byte_delay_us;
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xfers[index].tx_buf = &txbuf[index];
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spi_message_add_tail(&xfers[index], &msg);
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}
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if (bdata->block_delay_us)
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xfers[index - 1].delay_usecs = bdata->block_delay_us;
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retval = spi_sync(spi, &msg);
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if (retval == 0) {
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rmi4_data->current_page = page;
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retval = PAGE_SELECT_LEN;
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} else {
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dev_err(rmi4_data->pdev->dev.parent,
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"%s: Failed to complete SPI transfer, error = %d\n",
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__func__, retval);
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}
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} else {
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retval = PAGE_SELECT_LEN;
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}
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return retval;
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}
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static int synaptics_rmi4_spi_read(struct synaptics_rmi4_data *rmi4_data,
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unsigned short addr, unsigned char *data, unsigned short length)
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{
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int retval;
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unsigned int index;
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unsigned int xfer_count = length + ADDRESS_WORD_LEN;
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unsigned char txbuf[ADDRESS_WORD_LEN];
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unsigned char *rxbuf = NULL;
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struct spi_message msg;
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struct spi_transfer *xfers = NULL;
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struct spi_device *spi = to_spi_device(rmi4_data->pdev->dev.parent);
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const struct synaptics_dsx_board_data *bdata =
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rmi4_data->hw_if->board_data;
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spi_message_init(&msg);
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xfers = kcalloc(xfer_count, sizeof(struct spi_transfer), GFP_KERNEL);
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if (!xfers) {
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dev_err(rmi4_data->pdev->dev.parent,
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"%s: Failed to allocate memory for xfers\n",
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__func__);
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retval = -ENOMEM;
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goto exit;
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}
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txbuf[0] = (addr >> 8) | SPI_READ;
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txbuf[1] = addr & MASK_8BIT;
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rxbuf = kmalloc(length, GFP_KERNEL);
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if (!rxbuf) {
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dev_err(rmi4_data->pdev->dev.parent,
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"%s: Failed to allocate memory for rxbuf\n",
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__func__);
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retval = -ENOMEM;
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goto exit;
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}
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mutex_lock(&rmi4_data->rmi4_io_ctrl_mutex);
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retval = synaptics_rmi4_spi_set_page(rmi4_data, addr);
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if (retval != PAGE_SELECT_LEN) {
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retval = -EIO;
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goto exit;
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}
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for (index = 0; index < xfer_count; index++) {
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xfers[index].len = 1;
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xfers[index].delay_usecs = bdata->byte_delay_us;
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if (index < ADDRESS_WORD_LEN)
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xfers[index].tx_buf = &txbuf[index];
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else
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xfers[index].rx_buf = &rxbuf[index - ADDRESS_WORD_LEN];
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spi_message_add_tail(&xfers[index], &msg);
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}
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if (bdata->block_delay_us)
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xfers[index - 1].delay_usecs = bdata->block_delay_us;
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retval = spi_sync(spi, &msg);
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if (retval == 0) {
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retval = length;
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memcpy(data, rxbuf, length);
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} else {
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dev_err(rmi4_data->pdev->dev.parent,
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"%s: Failed to complete SPI transfer, error = %d\n",
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__func__, retval);
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}
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mutex_unlock(&rmi4_data->rmi4_io_ctrl_mutex);
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exit:
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kfree(rxbuf);
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kfree(xfers);
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return retval;
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}
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static int synaptics_rmi4_spi_write(struct synaptics_rmi4_data *rmi4_data,
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unsigned short addr, unsigned char *data, unsigned short length)
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{
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int retval;
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unsigned int index;
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unsigned int xfer_count = length + ADDRESS_WORD_LEN;
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unsigned char *txbuf = NULL;
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struct spi_message msg;
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struct spi_transfer *xfers = NULL;
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struct spi_device *spi = to_spi_device(rmi4_data->pdev->dev.parent);
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const struct synaptics_dsx_board_data *bdata =
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rmi4_data->hw_if->board_data;
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spi_message_init(&msg);
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xfers = kcalloc(xfer_count, sizeof(struct spi_transfer), GFP_KERNEL);
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if (!xfers) {
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dev_err(rmi4_data->pdev->dev.parent,
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"%s: Failed to allocate memory for xfers\n",
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__func__);
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retval = -ENOMEM;
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goto exit;
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}
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txbuf = kmalloc(xfer_count, GFP_KERNEL);
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if (!txbuf) {
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dev_err(rmi4_data->pdev->dev.parent,
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"%s: Failed to allocate memory for txbuf\n",
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__func__);
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retval = -ENOMEM;
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goto exit;
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}
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txbuf[0] = (addr >> 8) & ~SPI_READ;
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txbuf[1] = addr & MASK_8BIT;
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memcpy(&txbuf[ADDRESS_WORD_LEN], data, length);
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mutex_lock(&rmi4_data->rmi4_io_ctrl_mutex);
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retval = synaptics_rmi4_spi_set_page(rmi4_data, addr);
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if (retval != PAGE_SELECT_LEN) {
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retval = -EIO;
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goto exit;
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}
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for (index = 0; index < xfer_count; index++) {
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xfers[index].len = 1;
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xfers[index].delay_usecs = bdata->byte_delay_us;
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xfers[index].tx_buf = &txbuf[index];
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spi_message_add_tail(&xfers[index], &msg);
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}
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if (bdata->block_delay_us)
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xfers[index - 1].delay_usecs = bdata->block_delay_us;
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retval = spi_sync(spi, &msg);
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if (retval == 0) {
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retval = length;
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} else {
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dev_err(rmi4_data->pdev->dev.parent,
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"%s: Failed to complete SPI transfer, error = %d\n",
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__func__, retval);
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}
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mutex_unlock(&rmi4_data->rmi4_io_ctrl_mutex);
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exit:
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kfree(txbuf);
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kfree(xfers);
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return retval;
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}
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static struct synaptics_dsx_bus_access bus_access = {
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.type = BUS_SPI,
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.read = synaptics_rmi4_spi_read,
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.write = synaptics_rmi4_spi_write,
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};
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static struct synaptics_dsx_hw_interface hw_if;
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static struct platform_device *synaptics_dsx_spi_device;
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static void synaptics_rmi4_spi_dev_release(struct device *dev)
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{
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kfree(synaptics_dsx_spi_device);
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return;
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}
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static int synaptics_rmi4_spi_probe(struct spi_device *spi)
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{
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int retval;
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if (spi->master->flags & SPI_MASTER_HALF_DUPLEX) {
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dev_err(&spi->dev,
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"%s: Full duplex not supported by host\n",
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__func__);
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return -EIO;
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}
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synaptics_dsx_spi_device = kzalloc(
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sizeof(struct platform_device),
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GFP_KERNEL);
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if (!synaptics_dsx_spi_device) {
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dev_err(&spi->dev,
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"%s: Failed to allocate memory for synaptics_dsx_spi_device\n",
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__func__);
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return -ENOMEM;
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}
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spi->bits_per_word = 8;
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spi->mode = SPI_MODE_3;
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retval = spi_setup(spi);
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if (retval < 0) {
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dev_err(&spi->dev,
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"%s: Failed to perform SPI setup\n",
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__func__);
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return retval;
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}
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hw_if.board_data = spi->dev.platform_data;
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hw_if.bus_access = &bus_access;
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synaptics_dsx_spi_device->name = PLATFORM_DRIVER_NAME;
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synaptics_dsx_spi_device->id = 0;
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synaptics_dsx_spi_device->num_resources = 0;
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synaptics_dsx_spi_device->dev.parent = &spi->dev;
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synaptics_dsx_spi_device->dev.platform_data = &hw_if;
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synaptics_dsx_spi_device->dev.release = synaptics_rmi4_spi_dev_release;
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retval = platform_device_register(synaptics_dsx_spi_device);
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if (retval) {
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dev_err(&spi->dev,
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"%s: Failed to register platform device\n",
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__func__);
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return -ENODEV;
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}
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return 0;
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}
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static int synaptics_rmi4_spi_remove(struct spi_device *spi)
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{
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platform_device_unregister(synaptics_dsx_spi_device);
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return 0;
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}
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static struct spi_driver synaptics_rmi4_spi_driver = {
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.driver = {
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.name = SPI_DRIVER_NAME,
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.owner = THIS_MODULE,
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},
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.probe = synaptics_rmi4_spi_probe,
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.remove = __devexit_p(synaptics_rmi4_spi_remove),
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};
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int synaptics_rmi4_bus_init(void)
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{
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return spi_register_driver(&synaptics_rmi4_spi_driver);
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}
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EXPORT_SYMBOL(synaptics_rmi4_bus_init);
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void synaptics_rmi4_bus_exit(void)
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{
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spi_unregister_driver(&synaptics_rmi4_spi_driver);
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return;
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}
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EXPORT_SYMBOL(synaptics_rmi4_bus_exit);
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MODULE_AUTHOR("Synaptics, Inc.");
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MODULE_DESCRIPTION("Synaptics DSX SPI Bus Support Module");
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MODULE_LICENSE("GPL v2");
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