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/*
* arch/arm/mach-u300/spi.c
*
* Copyright (C) 2009 ST-Ericsson AB
* License terms: GNU General Public License (GPL) version 2
*
* Author: Linus Walleij <linus.walleij@stericsson.com>
*/
#include <linux/device.h>
#include <linux/amba/bus.h>
#include <linux/spi/spi.h>
#include <linux/amba/pl022.h>
#include <linux/err.h>
#include "padmux.h"
/*
* The following is for the actual devices on the SSP/SPI bus
*/
#ifdef CONFIG_MACH_U300_SPIDUMMY
static void select_dummy_chip(u32 chipselect)
{
pr_debug("CORE: %s called with CS=0x%x (%s)\n",
__func__,
chipselect,
chipselect ? "unselect chip" : "select chip");
/*
* Here you would write the chip select value to the GPIO pins if
* this was a real chip (but this is a loopback dummy).
*/
}
struct pl022_config_chip dummy_chip_info = {
/* Nominally this is LOOPBACK_DISABLED, but this is our dummy chip! */
.lbm = LOOPBACK_ENABLED,
/*
* available POLLING_TRANSFER and INTERRUPT_TRANSFER,
* DMA_TRANSFER does not work
*/
.com_mode = INTERRUPT_TRANSFER,
.iface = SSP_INTERFACE_MOTOROLA_SPI,
/* We can only act as master but SSP_SLAVE is possible in theory */
.hierarchy = SSP_MASTER,
/* 0 = drive TX even as slave, 1 = do not drive TX as slave */
.slave_tx_disable = 0,
/* LSB first */
.endian_tx = SSP_TX_LSB,
.endian_rx = SSP_RX_LSB,
.data_size = SSP_DATA_BITS_8, /* used to be 12 in some default */
.rx_lev_trig = SSP_RX_1_OR_MORE_ELEM,
.tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC,
.clk_phase = SSP_CLK_FALLING_EDGE,
.clk_pol = SSP_CLK_POL_IDLE_LOW,
.ctrl_len = SSP_BITS_12,
.wait_state = SSP_MWIRE_WAIT_ZERO,
.duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX,
/*
* This is where you insert a call to a function to enable CS
* (usually GPIO) for a certain chip.
*/
.cs_control = select_dummy_chip,
};
#endif
static struct spi_board_info u300_spi_devices[] = {
#ifdef CONFIG_MACH_U300_SPIDUMMY
{
/* A dummy chip used for loopback tests */
.modalias = "spi-dummy",
/* Really dummy, pass in additional chip config here */
.platform_data = NULL,
/* This defines how the controller shall handle the device */
.controller_data = &dummy_chip_info,
/* .irq - no external IRQ routed from this device */
.max_speed_hz = 1000000,
.bus_num = 0, /* Only one bus on this chip */
.chip_select = 0,
/* Means SPI_CS_HIGH, change if e.g low CS */
.mode = 0,
},
#endif
};
static struct pl022_ssp_controller ssp_platform_data = {
/* If you have several SPI buses this varies, we have only bus 0 */
.bus_id = 0,
/* Set this to 1 when we think we got DMA working */
.enable_dma = 0,
/*
* On the APP CPU GPIO 4, 5 and 6 are connected as generic
* chip selects for SPI. (Same on U330, U335 and U365.)
* TODO: make sure the GPIO driver can select these properly
* and do padmuxing accordingly too.
*/
.num_chipselect = 3,
};
void __init u300_spi_init(struct amba_device *adev)
{
struct pmx *pmx;
adev->dev.platform_data = &ssp_platform_data;
/*
* Setup padmuxing for SPI. Since this must always be
* compiled into the kernel, pmx is never released.
*/
pmx = pmx_get(&adev->dev, U300_APP_PMX_SPI_SETTING);
if (IS_ERR(pmx))
dev_warn(&adev->dev, "Could not get padmux handle\n");
else {
int ret;
ret = pmx_activate(&adev->dev, pmx);
if (IS_ERR_VALUE(ret))
dev_warn(&adev->dev, "Could not activate padmuxing\n");
}
}
void __init u300_spi_register_board_devices(void)
{
/* Register any SPI devices */
spi_register_board_info(u300_spi_devices, ARRAY_SIZE(u300_spi_devices));
}
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