2 * Atheros AP83 board specific SPI Controller driver
4 * Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
12 #include <linux/kernel.h>
13 #include <linux/init.h>
14 #include <linux/delay.h>
15 #include <linux/spinlock.h>
16 #include <linux/workqueue.h>
17 #include <linux/platform_device.h>
19 #include <linux/spi/spi.h>
20 #include <linux/spi/spi_bitbang.h>
21 #include <linux/bitops.h>
22 #include <linux/gpio.h>
24 #include <asm/mach-ar71xx/ar71xx.h>
25 #include <asm/mach-ar71xx/platform.h>
27 #define DRV_DESC "Atheros AP83 board SPI Controller driver"
28 #define DRV_VERSION "0.1.0"
29 #define DRV_NAME "ap83-spi"
31 #define AP83_SPI_CLK_HIGH (1 << 23)
32 #define AP83_SPI_CLK_LOW 0
33 #define AP83_SPI_MOSI_HIGH (1 << 22)
34 #define AP83_SPI_MOSI_LOW 0
36 #define AP83_SPI_GPIO_CS 1
37 #define AP83_SPI_GPIO_MISO 3
40 struct spi_bitbang bitbang;
44 struct platform_device *pdev;
47 static inline u32 ap83_spi_rr(struct ap83_spi *sp, u32 reg)
49 return __raw_readl(sp->base + reg);
52 static inline struct ap83_spi *spidev_to_sp(struct spi_device *spi)
54 return spi_master_get_devdata(spi->master);
57 static inline void setsck(struct spi_device *spi, int val)
59 struct ap83_spi *sp = spidev_to_sp(spi);
62 sp->addr |= AP83_SPI_CLK_HIGH;
64 sp->addr &= ~AP83_SPI_CLK_HIGH;
66 dev_dbg(&spi->dev, "addr=%08x, SCK set to %s\n",
67 sp->addr, (val) ? "HIGH" : "LOW");
69 ap83_spi_rr(sp, sp->addr);
72 static inline void setmosi(struct spi_device *spi, int val)
74 struct ap83_spi *sp = spidev_to_sp(spi);
77 sp->addr |= AP83_SPI_MOSI_HIGH;
79 sp->addr &= ~AP83_SPI_MOSI_HIGH;
81 dev_dbg(&spi->dev, "addr=%08x, MOSI set to %s\n",
82 sp->addr, (val) ? "HIGH" : "LOW");
84 ap83_spi_rr(sp, sp->addr);
87 static inline u32 getmiso(struct spi_device *spi)
91 ret = gpio_get_value(AP83_SPI_GPIO_MISO) ? 1 : 0;
92 dev_dbg(&spi->dev, "get MISO: %d\n", ret);
97 static inline void do_spidelay(struct spi_device *spi, unsigned nsecs)
102 static void ap83_spi_chipselect(struct spi_device *spi, int on)
104 struct ap83_spi *sp = spidev_to_sp(spi);
106 dev_dbg(&spi->dev, "set CS to %d\n", (on) ? 0 : 1);
109 ar71xx_flash_acquire();
112 ap83_spi_rr(sp, sp->addr);
114 gpio_set_value(AP83_SPI_GPIO_CS, 0);
116 gpio_set_value(AP83_SPI_GPIO_CS, 1);
117 ar71xx_flash_release();
121 #define spidelay(nsecs) \
123 /* Steal the spi_device pointer from our caller. \
124 * The bitbang-API should probably get fixed here... */ \
125 do_spidelay(spi, nsecs); \
128 #define EXPAND_BITBANG_TXRX
129 #include <linux/spi/spi_bitbang.h>
130 #include "spi_bitbang_txrx.h"
132 static u32 ap83_spi_txrx_mode0(struct spi_device *spi,
133 unsigned nsecs, u32 word, u8 bits)
135 dev_dbg(&spi->dev, "TXRX0 word=%08x, bits=%u\n", word, bits);
136 return bitbang_txrx_be_cpha0(spi, nsecs, 0, 0, word, bits);
139 static u32 ap83_spi_txrx_mode1(struct spi_device *spi,
140 unsigned nsecs, u32 word, u8 bits)
142 dev_dbg(&spi->dev, "TXRX1 word=%08x, bits=%u\n", word, bits);
143 return bitbang_txrx_be_cpha1(spi, nsecs, 0, 0, word, bits);
146 static u32 ap83_spi_txrx_mode2(struct spi_device *spi,
147 unsigned nsecs, u32 word, u8 bits)
149 dev_dbg(&spi->dev, "TXRX2 word=%08x, bits=%u\n", word, bits);
150 return bitbang_txrx_be_cpha0(spi, nsecs, 1, 0, word, bits);
153 static u32 ap83_spi_txrx_mode3(struct spi_device *spi,
154 unsigned nsecs, u32 word, u8 bits)
156 dev_dbg(&spi->dev, "TXRX3 word=%08x, bits=%u\n", word, bits);
157 return bitbang_txrx_be_cpha1(spi, nsecs, 1, 0, word, bits);
160 static int ap83_spi_probe(struct platform_device *pdev)
162 struct spi_master *master;
164 struct ap83_spi_platform_data *pdata;
168 ret = gpio_request(AP83_SPI_GPIO_MISO, "spi-miso");
170 dev_err(&pdev->dev, "gpio request failed for MISO\n");
174 ret = gpio_request(AP83_SPI_GPIO_CS, "spi-cs");
176 dev_err(&pdev->dev, "gpio request failed for CS\n");
180 ret = gpio_direction_input(AP83_SPI_GPIO_MISO);
182 dev_err(&pdev->dev, "unable to set direction of MISO\n");
186 ret = gpio_direction_output(AP83_SPI_GPIO_CS, 0);
188 dev_err(&pdev->dev, "unable to set direction of CS\n");
192 master = spi_alloc_master(&pdev->dev, sizeof(*sp));
193 if (master == NULL) {
194 dev_err(&pdev->dev, "failed to allocate spi master\n");
198 sp = spi_master_get_devdata(master);
199 platform_set_drvdata(pdev, sp);
201 pdata = pdev->dev.platform_data;
203 sp->bitbang.master = spi_master_get(master);
204 sp->bitbang.chipselect = ap83_spi_chipselect;
205 sp->bitbang.txrx_word[SPI_MODE_0] = ap83_spi_txrx_mode0;
206 sp->bitbang.txrx_word[SPI_MODE_1] = ap83_spi_txrx_mode1;
207 sp->bitbang.txrx_word[SPI_MODE_2] = ap83_spi_txrx_mode2;
208 sp->bitbang.txrx_word[SPI_MODE_3] = ap83_spi_txrx_mode3;
210 sp->bitbang.master->bus_num = pdev->id;
211 sp->bitbang.master->num_chipselect = 1;
213 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
219 sp->base = ioremap_nocache(r->start, r->end - r->start + 1);
225 ret = spi_bitbang_start(&sp->bitbang);
229 dev_info(&pdev->dev, "AP83 SPI adapter at %08x\n", r->start);
236 platform_set_drvdata(pdev, NULL);
237 spi_master_put(sp->bitbang.master);
240 gpio_free(AP83_SPI_GPIO_CS);
242 gpio_free(AP83_SPI_GPIO_MISO);
246 static int ap83_spi_remove(struct platform_device *pdev)
248 struct ap83_spi *sp = platform_get_drvdata(pdev);
250 spi_bitbang_stop(&sp->bitbang);
252 platform_set_drvdata(pdev, NULL);
253 spi_master_put(sp->bitbang.master);
258 static struct platform_driver ap83_spi_drv = {
259 .probe = ap83_spi_probe,
260 .remove = ap83_spi_remove,
263 .owner = THIS_MODULE,
267 static int __init ap83_spi_init(void)
269 return platform_driver_register(&ap83_spi_drv);
271 module_init(ap83_spi_init);
273 static void __exit ap83_spi_exit(void)
275 platform_driver_unregister(&ap83_spi_drv);
277 module_exit(ap83_spi_exit);
279 MODULE_ALIAS("platform:" DRV_NAME);
280 MODULE_DESCRIPTION(DRV_DESC);
281 MODULE_VERSION(DRV_VERSION);
282 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
283 MODULE_LICENSE("GPL v2");