Linus Walleij | c7c8c78 | 2009-08-14 10:59:05 +0100 | [diff] [blame^] | 1 | /* |
| 2 | * arch/arm/mach-u300/spi.c |
| 3 | * |
| 4 | * Copyright (C) 2009 ST-Ericsson AB |
| 5 | * License terms: GNU General Public License (GPL) version 2 |
| 6 | * |
| 7 | * Author: Linus Walleij <linus.walleij@stericsson.com> |
| 8 | */ |
| 9 | #include <linux/device.h> |
| 10 | #include <linux/amba/bus.h> |
| 11 | #include <linux/spi/spi.h> |
| 12 | #include <linux/amba/pl022.h> |
| 13 | #include <linux/err.h> |
| 14 | #include "padmux.h" |
| 15 | |
| 16 | /* |
| 17 | * The following is for the actual devices on the SSP/SPI bus |
| 18 | */ |
| 19 | #ifdef CONFIG_MACH_U300_SPIDUMMY |
| 20 | static void select_dummy_chip(u32 chipselect) |
| 21 | { |
| 22 | pr_debug("CORE: %s called with CS=0x%x (%s)\n", |
| 23 | __func__, |
| 24 | chipselect, |
| 25 | chipselect ? "unselect chip" : "select chip"); |
| 26 | /* |
| 27 | * Here you would write the chip select value to the GPIO pins if |
| 28 | * this was a real chip (but this is a loopback dummy). |
| 29 | */ |
| 30 | } |
| 31 | |
| 32 | struct pl022_config_chip dummy_chip_info = { |
| 33 | /* Nominally this is LOOPBACK_DISABLED, but this is our dummy chip! */ |
| 34 | .lbm = LOOPBACK_ENABLED, |
| 35 | /* |
| 36 | * available POLLING_TRANSFER and INTERRUPT_TRANSFER, |
| 37 | * DMA_TRANSFER does not work |
| 38 | */ |
| 39 | .com_mode = INTERRUPT_TRANSFER, |
| 40 | .iface = SSP_INTERFACE_MOTOROLA_SPI, |
| 41 | /* We can only act as master but SSP_SLAVE is possible in theory */ |
| 42 | .hierarchy = SSP_MASTER, |
| 43 | /* 0 = drive TX even as slave, 1 = do not drive TX as slave */ |
| 44 | .slave_tx_disable = 0, |
| 45 | /* LSB first */ |
| 46 | .endian_tx = SSP_TX_LSB, |
| 47 | .endian_rx = SSP_RX_LSB, |
| 48 | .data_size = SSP_DATA_BITS_8, /* used to be 12 in some default */ |
| 49 | .rx_lev_trig = SSP_RX_1_OR_MORE_ELEM, |
| 50 | .tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC, |
| 51 | .clk_phase = SSP_CLK_FALLING_EDGE, |
| 52 | .clk_pol = SSP_CLK_POL_IDLE_LOW, |
| 53 | .ctrl_len = SSP_BITS_12, |
| 54 | .wait_state = SSP_MWIRE_WAIT_ZERO, |
| 55 | .duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX, |
| 56 | /* |
| 57 | * This is where you insert a call to a function to enable CS |
| 58 | * (usually GPIO) for a certain chip. |
| 59 | */ |
| 60 | .cs_control = select_dummy_chip, |
| 61 | }; |
| 62 | #endif |
| 63 | |
| 64 | static struct spi_board_info u300_spi_devices[] = { |
| 65 | #ifdef CONFIG_MACH_U300_SPIDUMMY |
| 66 | { |
| 67 | /* A dummy chip used for loopback tests */ |
| 68 | .modalias = "spi-dummy", |
| 69 | /* Really dummy, pass in additional chip config here */ |
| 70 | .platform_data = NULL, |
| 71 | /* This defines how the controller shall handle the device */ |
| 72 | .controller_data = &dummy_chip_info, |
| 73 | /* .irq - no external IRQ routed from this device */ |
| 74 | .max_speed_hz = 1000000, |
| 75 | .bus_num = 0, /* Only one bus on this chip */ |
| 76 | .chip_select = 0, |
| 77 | /* Means SPI_CS_HIGH, change if e.g low CS */ |
| 78 | .mode = 0, |
| 79 | }, |
| 80 | #endif |
| 81 | }; |
| 82 | |
| 83 | static struct pl022_ssp_controller ssp_platform_data = { |
| 84 | /* If you have several SPI buses this varies, we have only bus 0 */ |
| 85 | .bus_id = 0, |
| 86 | /* Set this to 1 when we think we got DMA working */ |
| 87 | .enable_dma = 0, |
| 88 | /* |
| 89 | * On the APP CPU GPIO 4, 5 and 6 are connected as generic |
| 90 | * chip selects for SPI. (Same on U330, U335 and U365.) |
| 91 | * TODO: make sure the GPIO driver can select these properly |
| 92 | * and do padmuxing accordingly too. |
| 93 | */ |
| 94 | .num_chipselect = 3, |
| 95 | }; |
| 96 | |
| 97 | |
| 98 | void __init u300_spi_init(struct amba_device *adev) |
| 99 | { |
| 100 | struct pmx *pmx; |
| 101 | |
| 102 | adev->dev.platform_data = &ssp_platform_data; |
| 103 | /* |
| 104 | * Setup padmuxing for SPI. Since this must always be |
| 105 | * compiled into the kernel, pmx is never released. |
| 106 | */ |
| 107 | pmx = pmx_get(&adev->dev, U300_APP_PMX_SPI_SETTING); |
| 108 | |
| 109 | if (IS_ERR(pmx)) |
| 110 | dev_warn(&adev->dev, "Could not get padmux handle\n"); |
| 111 | else { |
| 112 | int ret; |
| 113 | |
| 114 | ret = pmx_activate(&adev->dev, pmx); |
| 115 | if (IS_ERR_VALUE(ret)) |
| 116 | dev_warn(&adev->dev, "Could not activate padmuxing\n"); |
| 117 | } |
| 118 | |
| 119 | } |
| 120 | void __init u300_spi_register_board_devices(void) |
| 121 | { |
| 122 | /* Register any SPI devices */ |
| 123 | spi_register_board_info(u300_spi_devices, ARRAY_SIZE(u300_spi_devices)); |
| 124 | } |