]>
Commit | Line | Data |
---|---|---|
c7c8c78f LW |
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, | |
ee2b805c | 51 | .clk_phase = SSP_CLK_SECOND_EDGE, |
c7c8c78f LW |
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 | } |