From c7c8c78fdf6e9bd65d8ee879115dc2cd5d9fd0dc Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Fri, 14 Aug 2009 10:59:05 +0100 Subject: ARM: 5667/3: U300 SSP/SPI board setup and test This adds a U300 board configuration for the PL022 SSP/SPI PrimeCell driver recently merged to the 2.6.31-rc series. Further it adds a dummy loopback SPI chip that can be used for testing the SPI functionality on a running system using the loopback mode of PL022. Signed-off-by: Linus Walleij Signed-off-by: Russell King --- arch/arm/mach-u300/spi.c | 124 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 124 insertions(+) create mode 100644 arch/arm/mach-u300/spi.c (limited to 'arch/arm/mach-u300/spi.c') diff --git a/arch/arm/mach-u300/spi.c b/arch/arm/mach-u300/spi.c new file mode 100644 index 000000000000..307d007ea7f3 --- /dev/null +++ b/arch/arm/mach-u300/spi.c @@ -0,0 +1,124 @@ +/* + * 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_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)); +} -- cgit v1.2.3