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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 = { | |
c7c8c78f LW |
33 | /* |
34 | * available POLLING_TRANSFER and INTERRUPT_TRANSFER, | |
35 | * DMA_TRANSFER does not work | |
36 | */ | |
37 | .com_mode = INTERRUPT_TRANSFER, | |
38 | .iface = SSP_INTERFACE_MOTOROLA_SPI, | |
39 | /* We can only act as master but SSP_SLAVE is possible in theory */ | |
40 | .hierarchy = SSP_MASTER, | |
41 | /* 0 = drive TX even as slave, 1 = do not drive TX as slave */ | |
42 | .slave_tx_disable = 0, | |
c7c8c78f LW |
43 | .rx_lev_trig = SSP_RX_1_OR_MORE_ELEM, |
44 | .tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC, | |
c7c8c78f LW |
45 | .ctrl_len = SSP_BITS_12, |
46 | .wait_state = SSP_MWIRE_WAIT_ZERO, | |
47 | .duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX, | |
48 | /* | |
49 | * This is where you insert a call to a function to enable CS | |
50 | * (usually GPIO) for a certain chip. | |
51 | */ | |
52 | .cs_control = select_dummy_chip, | |
53 | }; | |
54 | #endif | |
55 | ||
56 | static struct spi_board_info u300_spi_devices[] = { | |
57 | #ifdef CONFIG_MACH_U300_SPIDUMMY | |
58 | { | |
59 | /* A dummy chip used for loopback tests */ | |
60 | .modalias = "spi-dummy", | |
61 | /* Really dummy, pass in additional chip config here */ | |
62 | .platform_data = NULL, | |
63 | /* This defines how the controller shall handle the device */ | |
64 | .controller_data = &dummy_chip_info, | |
65 | /* .irq - no external IRQ routed from this device */ | |
66 | .max_speed_hz = 1000000, | |
67 | .bus_num = 0, /* Only one bus on this chip */ | |
68 | .chip_select = 0, | |
69 | /* Means SPI_CS_HIGH, change if e.g low CS */ | |
65289d63 | 70 | .mode = SPI_MODE_1 | SPI_LOOP, |
c7c8c78f LW |
71 | }, |
72 | #endif | |
73 | }; | |
74 | ||
75 | static struct pl022_ssp_controller ssp_platform_data = { | |
76 | /* If you have several SPI buses this varies, we have only bus 0 */ | |
77 | .bus_id = 0, | |
78 | /* Set this to 1 when we think we got DMA working */ | |
79 | .enable_dma = 0, | |
80 | /* | |
81 | * On the APP CPU GPIO 4, 5 and 6 are connected as generic | |
82 | * chip selects for SPI. (Same on U330, U335 and U365.) | |
83 | * TODO: make sure the GPIO driver can select these properly | |
84 | * and do padmuxing accordingly too. | |
85 | */ | |
86 | .num_chipselect = 3, | |
87 | }; | |
88 | ||
89 | ||
90 | void __init u300_spi_init(struct amba_device *adev) | |
91 | { | |
92 | struct pmx *pmx; | |
93 | ||
94 | adev->dev.platform_data = &ssp_platform_data; | |
95 | /* | |
96 | * Setup padmuxing for SPI. Since this must always be | |
97 | * compiled into the kernel, pmx is never released. | |
98 | */ | |
99 | pmx = pmx_get(&adev->dev, U300_APP_PMX_SPI_SETTING); | |
100 | ||
101 | if (IS_ERR(pmx)) | |
102 | dev_warn(&adev->dev, "Could not get padmux handle\n"); | |
103 | else { | |
104 | int ret; | |
105 | ||
106 | ret = pmx_activate(&adev->dev, pmx); | |
107 | if (IS_ERR_VALUE(ret)) | |
108 | dev_warn(&adev->dev, "Could not activate padmuxing\n"); | |
109 | } | |
110 | ||
111 | } | |
112 | void __init u300_spi_register_board_devices(void) | |
113 | { | |
114 | /* Register any SPI devices */ | |
115 | spi_register_board_info(u300_spi_devices, ARRAY_SIZE(u300_spi_devices)); | |
116 | } |