/* * arch/arm/mach-u300/spi.c * * Copyright (C) 2009 ST-Ericsson AB * License terms: GNU General Public License (GPL) version 2 * * Author: Linus Walleij */ #include #include #include #include #include #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)); }