125 строки
3.5 KiB
C
125 строки
3.5 KiB
C
/*
|
|
* 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_SECOND_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));
|
|
}
|