Magnus Damm | 37e4664 | 2008-02-06 01:38:15 -0800 | [diff] [blame] | 1 | /* |
| 2 | * SH SCI SPI interface |
| 3 | * |
| 4 | * Copyright (c) 2008 Magnus Damm |
| 5 | * |
| 6 | * Based on S3C24XX GPIO based SPI driver, which is: |
| 7 | * Copyright (c) 2006 Ben Dooks |
| 8 | * Copyright (c) 2006 Simtec Electronics |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or modify |
| 11 | * it under the terms of the GNU General Public License version 2 as |
| 12 | * published by the Free Software Foundation. |
| 13 | * |
| 14 | */ |
| 15 | |
| 16 | #include <linux/kernel.h> |
Magnus Damm | 37e4664 | 2008-02-06 01:38:15 -0800 | [diff] [blame] | 17 | #include <linux/delay.h> |
| 18 | #include <linux/spinlock.h> |
| 19 | #include <linux/workqueue.h> |
| 20 | #include <linux/platform_device.h> |
| 21 | |
| 22 | #include <linux/spi/spi.h> |
| 23 | #include <linux/spi/spi_bitbang.h> |
Paul Gortmaker | d7614de | 2011-07-03 15:44:29 -0400 | [diff] [blame] | 24 | #include <linux/module.h> |
Magnus Damm | 37e4664 | 2008-02-06 01:38:15 -0800 | [diff] [blame] | 25 | |
| 26 | #include <asm/spi.h> |
| 27 | #include <asm/io.h> |
| 28 | |
| 29 | struct sh_sci_spi { |
| 30 | struct spi_bitbang bitbang; |
| 31 | |
| 32 | void __iomem *membase; |
| 33 | unsigned char val; |
| 34 | struct sh_spi_info *info; |
| 35 | struct platform_device *dev; |
| 36 | }; |
| 37 | |
| 38 | #define SCSPTR(sp) (sp->membase + 0x1c) |
| 39 | #define PIN_SCK (1 << 2) |
| 40 | #define PIN_TXD (1 << 0) |
| 41 | #define PIN_RXD PIN_TXD |
| 42 | #define PIN_INIT ((1 << 1) | (1 << 3) | PIN_SCK | PIN_TXD) |
| 43 | |
| 44 | static inline void setbits(struct sh_sci_spi *sp, int bits, int on) |
| 45 | { |
| 46 | /* |
| 47 | * We are the only user of SCSPTR so no locking is required. |
| 48 | * Reading bit 2 and 0 in SCSPTR gives pin state as input. |
| 49 | * Writing the same bits sets the output value. |
| 50 | * This makes regular read-modify-write difficult so we |
| 51 | * use sp->val to keep track of the latest register value. |
| 52 | */ |
| 53 | |
| 54 | if (on) |
| 55 | sp->val |= bits; |
| 56 | else |
| 57 | sp->val &= ~bits; |
| 58 | |
| 59 | iowrite8(sp->val, SCSPTR(sp)); |
| 60 | } |
| 61 | |
| 62 | static inline void setsck(struct spi_device *dev, int on) |
| 63 | { |
| 64 | setbits(spi_master_get_devdata(dev->master), PIN_SCK, on); |
| 65 | } |
| 66 | |
| 67 | static inline void setmosi(struct spi_device *dev, int on) |
| 68 | { |
| 69 | setbits(spi_master_get_devdata(dev->master), PIN_TXD, on); |
| 70 | } |
| 71 | |
| 72 | static inline u32 getmiso(struct spi_device *dev) |
| 73 | { |
| 74 | struct sh_sci_spi *sp = spi_master_get_devdata(dev->master); |
| 75 | |
| 76 | return (ioread8(SCSPTR(sp)) & PIN_RXD) ? 1 : 0; |
| 77 | } |
| 78 | |
| 79 | #define spidelay(x) ndelay(x) |
| 80 | |
Grant Likely | ca632f5 | 2011-06-06 01:16:30 -0600 | [diff] [blame] | 81 | #include "spi-bitbang-txrx.h" |
Magnus Damm | 37e4664 | 2008-02-06 01:38:15 -0800 | [diff] [blame] | 82 | |
| 83 | static u32 sh_sci_spi_txrx_mode0(struct spi_device *spi, |
| 84 | unsigned nsecs, u32 word, u8 bits) |
| 85 | { |
Marek Szyprowski | 04bb2a0 | 2010-06-30 14:27:32 -0600 | [diff] [blame] | 86 | return bitbang_txrx_be_cpha0(spi, nsecs, 0, 0, word, bits); |
Magnus Damm | 37e4664 | 2008-02-06 01:38:15 -0800 | [diff] [blame] | 87 | } |
| 88 | |
| 89 | static u32 sh_sci_spi_txrx_mode1(struct spi_device *spi, |
| 90 | unsigned nsecs, u32 word, u8 bits) |
| 91 | { |
Marek Szyprowski | 04bb2a0 | 2010-06-30 14:27:32 -0600 | [diff] [blame] | 92 | return bitbang_txrx_be_cpha1(spi, nsecs, 0, 0, word, bits); |
Magnus Damm | 37e4664 | 2008-02-06 01:38:15 -0800 | [diff] [blame] | 93 | } |
| 94 | |
| 95 | static u32 sh_sci_spi_txrx_mode2(struct spi_device *spi, |
| 96 | unsigned nsecs, u32 word, u8 bits) |
| 97 | { |
Marek Szyprowski | 04bb2a0 | 2010-06-30 14:27:32 -0600 | [diff] [blame] | 98 | return bitbang_txrx_be_cpha0(spi, nsecs, 1, 0, word, bits); |
Magnus Damm | 37e4664 | 2008-02-06 01:38:15 -0800 | [diff] [blame] | 99 | } |
| 100 | |
| 101 | static u32 sh_sci_spi_txrx_mode3(struct spi_device *spi, |
| 102 | unsigned nsecs, u32 word, u8 bits) |
| 103 | { |
Marek Szyprowski | 04bb2a0 | 2010-06-30 14:27:32 -0600 | [diff] [blame] | 104 | return bitbang_txrx_be_cpha1(spi, nsecs, 1, 0, word, bits); |
Magnus Damm | 37e4664 | 2008-02-06 01:38:15 -0800 | [diff] [blame] | 105 | } |
| 106 | |
| 107 | static void sh_sci_spi_chipselect(struct spi_device *dev, int value) |
| 108 | { |
| 109 | struct sh_sci_spi *sp = spi_master_get_devdata(dev->master); |
| 110 | |
Axel Lin | ed8eb25 | 2014-03-13 10:32:37 +0800 | [diff] [blame] | 111 | if (sp->info->chip_select) |
Magnus Damm | 37e4664 | 2008-02-06 01:38:15 -0800 | [diff] [blame] | 112 | (sp->info->chip_select)(sp->info, dev->chip_select, value); |
| 113 | } |
| 114 | |
| 115 | static int sh_sci_spi_probe(struct platform_device *dev) |
| 116 | { |
| 117 | struct resource *r; |
| 118 | struct spi_master *master; |
| 119 | struct sh_sci_spi *sp; |
| 120 | int ret; |
| 121 | |
| 122 | master = spi_alloc_master(&dev->dev, sizeof(struct sh_sci_spi)); |
| 123 | if (master == NULL) { |
| 124 | dev_err(&dev->dev, "failed to allocate spi master\n"); |
| 125 | ret = -ENOMEM; |
| 126 | goto err0; |
| 127 | } |
| 128 | |
| 129 | sp = spi_master_get_devdata(master); |
| 130 | |
| 131 | platform_set_drvdata(dev, sp); |
Jingoo Han | 8074cf0 | 2013-07-30 16:58:59 +0900 | [diff] [blame] | 132 | sp->info = dev_get_platdata(&dev->dev); |
Axel Lin | ed8eb25 | 2014-03-13 10:32:37 +0800 | [diff] [blame] | 133 | if (!sp->info) { |
| 134 | dev_err(&dev->dev, "platform data is missing\n"); |
| 135 | ret = -ENOENT; |
| 136 | goto err1; |
| 137 | } |
Magnus Damm | 37e4664 | 2008-02-06 01:38:15 -0800 | [diff] [blame] | 138 | |
| 139 | /* setup spi bitbang adaptor */ |
Axel Lin | 94c69f7 | 2013-09-10 15:43:41 +0800 | [diff] [blame] | 140 | sp->bitbang.master = master; |
Magnus Damm | 37e4664 | 2008-02-06 01:38:15 -0800 | [diff] [blame] | 141 | sp->bitbang.master->bus_num = sp->info->bus_num; |
| 142 | sp->bitbang.master->num_chipselect = sp->info->num_chipselect; |
| 143 | sp->bitbang.chipselect = sh_sci_spi_chipselect; |
| 144 | |
| 145 | sp->bitbang.txrx_word[SPI_MODE_0] = sh_sci_spi_txrx_mode0; |
| 146 | sp->bitbang.txrx_word[SPI_MODE_1] = sh_sci_spi_txrx_mode1; |
| 147 | sp->bitbang.txrx_word[SPI_MODE_2] = sh_sci_spi_txrx_mode2; |
| 148 | sp->bitbang.txrx_word[SPI_MODE_3] = sh_sci_spi_txrx_mode3; |
| 149 | |
| 150 | r = platform_get_resource(dev, IORESOURCE_MEM, 0); |
| 151 | if (r == NULL) { |
| 152 | ret = -ENOENT; |
| 153 | goto err1; |
| 154 | } |
hartleys | 76b6fdd | 2009-12-14 22:40:05 +0000 | [diff] [blame] | 155 | sp->membase = ioremap(r->start, resource_size(r)); |
Magnus Damm | 37e4664 | 2008-02-06 01:38:15 -0800 | [diff] [blame] | 156 | if (!sp->membase) { |
| 157 | ret = -ENXIO; |
| 158 | goto err1; |
| 159 | } |
| 160 | sp->val = ioread8(SCSPTR(sp)); |
| 161 | setbits(sp, PIN_INIT, 1); |
| 162 | |
| 163 | ret = spi_bitbang_start(&sp->bitbang); |
| 164 | if (!ret) |
| 165 | return 0; |
| 166 | |
| 167 | setbits(sp, PIN_INIT, 0); |
| 168 | iounmap(sp->membase); |
| 169 | err1: |
| 170 | spi_master_put(sp->bitbang.master); |
| 171 | err0: |
| 172 | return ret; |
| 173 | } |
| 174 | |
| 175 | static int sh_sci_spi_remove(struct platform_device *dev) |
| 176 | { |
| 177 | struct sh_sci_spi *sp = platform_get_drvdata(dev); |
| 178 | |
| 179 | iounmap(sp->membase); |
| 180 | setbits(sp, PIN_INIT, 0); |
| 181 | spi_bitbang_stop(&sp->bitbang); |
| 182 | spi_master_put(sp->bitbang.master); |
| 183 | return 0; |
| 184 | } |
| 185 | |
| 186 | static struct platform_driver sh_sci_spi_drv = { |
| 187 | .probe = sh_sci_spi_probe, |
| 188 | .remove = sh_sci_spi_remove, |
| 189 | .driver = { |
| 190 | .name = "spi_sh_sci", |
| 191 | .owner = THIS_MODULE, |
| 192 | }, |
| 193 | }; |
Grant Likely | 940ab88 | 2011-10-05 11:29:49 -0600 | [diff] [blame] | 194 | module_platform_driver(sh_sci_spi_drv); |
Magnus Damm | 37e4664 | 2008-02-06 01:38:15 -0800 | [diff] [blame] | 195 | |
| 196 | MODULE_DESCRIPTION("SH SCI SPI Driver"); |
| 197 | MODULE_AUTHOR("Magnus Damm <damm@opensource.se>"); |
| 198 | MODULE_LICENSE("GPL"); |
Kay Sievers | 7e38c3c | 2008-04-10 21:29:20 -0700 | [diff] [blame] | 199 | MODULE_ALIAS("platform:spi_sh_sci"); |