spi: Add AD-FMCOMMS1-EBZ I2C-SPI bridge driver
This patch adds support for the I2C-SPI bridge which can be found on the Analog Devices AD-FMCOMMS1-EBZ board. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
This commit is contained in:
Lars-Peter Clausen
Mark Brown
parent
8b17e0559f
commit
b316590043
@ -384,6 +384,13 @@ config SPI_TXX9
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help
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SPI driver for Toshiba TXx9 MIPS SoCs
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config SPI_XCOMM
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tristate "Analog Devices AD-FMCOMMS1-EBZ SPI-I2C-bridge driver"
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depends on I2C
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help
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Support for the SPI-I2C bridge found on the Analog Devices
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AD-FMCOMMS1-EBZ board.
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config SPI_XILINX
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tristate "Xilinx SPI controller common module"
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depends on HAS_IOMEM && EXPERIMENTAL
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@ -61,5 +61,6 @@ obj-$(CONFIG_SPI_TI_SSP) += spi-ti-ssp.o
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obj-$(CONFIG_SPI_TLE62X0) += spi-tle62x0.o
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obj-$(CONFIG_SPI_TOPCLIFF_PCH) += spi-topcliff-pch.o
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obj-$(CONFIG_SPI_TXX9) += spi-txx9.o
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obj-$(CONFIG_SPI_XCOMM) += spi-xcomm.o
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obj-$(CONFIG_SPI_XILINX) += spi-xilinx.o
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276
drivers/spi/spi-xcomm.c
Normal file
276
drivers/spi/spi-xcomm.c
Normal file
@ -0,0 +1,276 @@
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/*
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* Analog Devices AD-FMCOMMS1-EBZ board I2C-SPI bridge driver
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*
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* Copyright 2012 Analog Devices Inc.
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* Author: Lars-Peter Clausen <lars@metafoo.de>
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*
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* Licensed under the GPL-2 or later.
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/delay.h>
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#include <linux/i2c.h>
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#include <linux/spi/spi.h>
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#include <asm/unaligned.h>
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#define SPI_XCOMM_SETTINGS_LEN_OFFSET 10
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#define SPI_XCOMM_SETTINGS_3WIRE BIT(6)
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#define SPI_XCOMM_SETTINGS_CS_HIGH BIT(5)
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#define SPI_XCOMM_SETTINGS_SAMPLE_END BIT(4)
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#define SPI_XCOMM_SETTINGS_CPHA BIT(3)
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#define SPI_XCOMM_SETTINGS_CPOL BIT(2)
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#define SPI_XCOMM_SETTINGS_CLOCK_DIV_MASK 0x3
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#define SPI_XCOMM_SETTINGS_CLOCK_DIV_64 0x2
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#define SPI_XCOMM_SETTINGS_CLOCK_DIV_16 0x1
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#define SPI_XCOMM_SETTINGS_CLOCK_DIV_4 0x0
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#define SPI_XCOMM_CMD_UPDATE_CONFIG 0x03
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#define SPI_XCOMM_CMD_WRITE 0x04
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#define SPI_XCOMM_CLOCK 48000000
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struct spi_xcomm {
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struct i2c_client *i2c;
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uint16_t settings;
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uint16_t chipselect;
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unsigned int current_speed;
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uint8_t buf[63];
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};
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static int spi_xcomm_sync_config(struct spi_xcomm *spi_xcomm, unsigned int len)
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{
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uint16_t settings;
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uint8_t *buf = spi_xcomm->buf;
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settings = spi_xcomm->settings;
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settings |= len << SPI_XCOMM_SETTINGS_LEN_OFFSET;
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buf[0] = SPI_XCOMM_CMD_UPDATE_CONFIG;
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put_unaligned_be16(settings, &buf[1]);
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put_unaligned_be16(spi_xcomm->chipselect, &buf[3]);
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return i2c_master_send(spi_xcomm->i2c, buf, 5);
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}
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static void spi_xcomm_chipselect(struct spi_xcomm *spi_xcomm,
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struct spi_device *spi, int is_active)
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{
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unsigned long cs = spi->chip_select;
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uint16_t chipselect = spi_xcomm->chipselect;
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if (is_active)
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chipselect |= BIT(cs);
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else
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chipselect &= ~BIT(cs);
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spi_xcomm->chipselect = chipselect;
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}
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static int spi_xcomm_setup_transfer(struct spi_xcomm *spi_xcomm,
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struct spi_device *spi, struct spi_transfer *t, unsigned int *settings)
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{
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unsigned int speed;
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if ((t->bits_per_word && t->bits_per_word != 8) || t->len > 62)
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return -EINVAL;
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speed = t->speed_hz ? t->speed_hz : spi->max_speed_hz;
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if (speed != spi_xcomm->current_speed) {
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unsigned int divider = DIV_ROUND_UP(SPI_XCOMM_CLOCK, speed);
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if (divider >= 64)
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*settings |= SPI_XCOMM_SETTINGS_CLOCK_DIV_64;
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else if (divider >= 16)
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*settings |= SPI_XCOMM_SETTINGS_CLOCK_DIV_16;
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else
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*settings |= SPI_XCOMM_SETTINGS_CLOCK_DIV_4;
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spi_xcomm->current_speed = speed;
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}
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if (spi->mode & SPI_CPOL)
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*settings |= SPI_XCOMM_SETTINGS_CPOL;
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else
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*settings &= ~SPI_XCOMM_SETTINGS_CPOL;
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if (spi->mode & SPI_CPHA)
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*settings &= ~SPI_XCOMM_SETTINGS_CPHA;
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else
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*settings |= SPI_XCOMM_SETTINGS_CPHA;
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if (spi->mode & SPI_3WIRE)
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*settings |= SPI_XCOMM_SETTINGS_3WIRE;
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else
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*settings &= ~SPI_XCOMM_SETTINGS_3WIRE;
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return 0;
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}
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static int spi_xcomm_txrx_bufs(struct spi_xcomm *spi_xcomm,
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struct spi_device *spi, struct spi_transfer *t)
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{
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int ret;
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if (t->tx_buf) {
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spi_xcomm->buf[0] = SPI_XCOMM_CMD_WRITE;
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memcpy(spi_xcomm->buf + 1, t->tx_buf, t->len);
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ret = i2c_master_send(spi_xcomm->i2c, spi_xcomm->buf, t->len + 1);
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if (ret < 0)
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return ret;
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else if (ret != t->len + 1)
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return -EIO;
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} else if (t->rx_buf) {
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ret = i2c_master_recv(spi_xcomm->i2c, t->rx_buf, t->len);
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if (ret < 0)
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return ret;
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else if (ret != t->len)
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return -EIO;
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}
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return t->len;
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}
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static int spi_xcomm_transfer_one(struct spi_master *master,
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struct spi_message *msg)
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{
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struct spi_xcomm *spi_xcomm = spi_master_get_devdata(master);
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unsigned int settings = spi_xcomm->settings;
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struct spi_device *spi = msg->spi;
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unsigned cs_change = 0;
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struct spi_transfer *t;
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bool is_first = true;
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int status = 0;
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bool is_last;
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is_first = true;
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spi_xcomm_chipselect(spi_xcomm, spi, true);
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list_for_each_entry(t, &msg->transfers, transfer_list) {
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if (!t->tx_buf && !t->rx_buf && t->len) {
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status = -EINVAL;
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break;
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}
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status = spi_xcomm_setup_transfer(spi_xcomm, spi, t, &settings);
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if (status < 0)
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break;
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is_last = list_is_last(&t->transfer_list, &msg->transfers);
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cs_change = t->cs_change;
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if (cs_change ^ is_last)
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settings |= BIT(5);
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else
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settings &= ~BIT(5);
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if (t->rx_buf) {
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spi_xcomm->settings = settings;
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status = spi_xcomm_sync_config(spi_xcomm, t->len);
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if (status < 0)
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break;
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} else if (settings != spi_xcomm->settings || is_first) {
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spi_xcomm->settings = settings;
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status = spi_xcomm_sync_config(spi_xcomm, 0);
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if (status < 0)
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break;
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}
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if (t->len) {
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status = spi_xcomm_txrx_bufs(spi_xcomm, spi, t);
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if (status < 0)
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break;
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if (status > 0)
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msg->actual_length += status;
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}
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status = 0;
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if (t->delay_usecs)
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udelay(t->delay_usecs);
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is_first = false;
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}
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if (status != 0 || !cs_change)
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spi_xcomm_chipselect(spi_xcomm, spi, false);
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msg->status = status;
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spi_finalize_current_message(master);
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return status;
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}
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static int spi_xcomm_setup(struct spi_device *spi)
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{
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if (spi->bits_per_word != 8)
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return -EINVAL;
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return 0;
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}
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static int __devinit spi_xcomm_probe(struct i2c_client *i2c,
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const struct i2c_device_id *id)
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{
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struct spi_xcomm *spi_xcomm;
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struct spi_master *master;
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int ret;
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master = spi_alloc_master(&i2c->dev, sizeof(*spi_xcomm));
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if (!master)
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return -ENOMEM;
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spi_xcomm = spi_master_get_devdata(master);
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spi_xcomm->i2c = i2c;
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master->num_chipselect = 16;
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master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_3WIRE;
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master->flags = SPI_MASTER_HALF_DUPLEX;
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master->setup = spi_xcomm_setup;
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master->transfer_one_message = spi_xcomm_transfer_one;
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master->dev.of_node = i2c->dev.of_node;
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i2c_set_clientdata(i2c, master);
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ret = spi_register_master(master);
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if (ret < 0)
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spi_master_put(master);
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return ret;
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}
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static int __devexit spi_xcomm_remove(struct i2c_client *i2c)
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{
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struct spi_master *master = i2c_get_clientdata(i2c);
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spi_unregister_master(master);
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return 0;
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}
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static const struct i2c_device_id spi_xcomm_ids[] = {
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{ "spi-xcomm" },
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{ },
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};
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static struct i2c_driver spi_xcomm_driver = {
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.driver = {
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.name = "spi-xcomm",
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.owner = THIS_MODULE,
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},
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.id_table = spi_xcomm_ids,
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.probe = spi_xcomm_probe,
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.remove = __devexit_p(spi_xcomm_remove),
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};
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module_i2c_driver(spi_xcomm_driver);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
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MODULE_DESCRIPTION("Analog Devices AD-FMCOMMS1-EBZ board I2C-SPI bridge driver");
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