Merge branch 'x86-txt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-block.git] / drivers / ide / at91_ide.c
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1/*
2 * IDE host driver for AT91 (SAM9, CAP9, AT572D940HF) Static Memory Controller
3 * with Compact Flash True IDE logic
4 *
5 * Copyright (c) 2008, 2009 Kelvatek Ltd.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 *
21 */
22
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23#include <linux/kernel.h>
24#include <linux/module.h>
25#include <linux/clk.h>
26#include <linux/err.h>
27#include <linux/ide.h>
28#include <linux/platform_device.h>
29
30#include <mach/board.h>
31#include <mach/gpio.h>
32#include <mach/at91sam9263.h>
33#include <mach/at91sam9_smc.h>
34#include <mach/at91sam9263_matrix.h>
35
36#define DRV_NAME "at91_ide"
37
38#define perr(fmt, args...) pr_err(DRV_NAME ": " fmt, ##args)
39#define pdbg(fmt, args...) pr_debug("%s " fmt, __func__, ##args)
40
41/*
42 * Access to IDE device is possible through EBI Static Memory Controller
43 * with Compact Flash logic. For details see EBI and SMC datasheet sections
44 * of any microcontroller from AT91SAM9 family.
45 *
46 * Within SMC chip select address space, lines A[23:21] distinguish Compact
47 * Flash modes (I/O, common memory, attribute memory, True IDE). IDE modes are:
48 * 0x00c0000 - True IDE
49 * 0x00e0000 - Alternate True IDE (Alt Status Register)
50 *
51 * On True IDE mode Task File and Data Register are mapped at the same address.
52 * To distinguish access between these two different bus data width is used:
53 * 8Bit for Task File, 16Bit for Data I/O.
54 *
55 * After initialization we do 8/16 bit flipping (changes in SMC MODE register)
56 * only inside IDE callback routines which are serialized by IDE layer,
57 * so no additional locking needed.
58 */
59
60#define TASK_FILE 0x00c00000
61#define ALT_MODE 0x00e00000
62#define REGS_SIZE 8
63
64#define enter_16bit(cs, mode) do { \
65 mode = at91_sys_read(AT91_SMC_MODE(cs)); \
66 at91_sys_write(AT91_SMC_MODE(cs), mode | AT91_SMC_DBW_16); \
67} while (0)
68
69#define leave_16bit(cs, mode) at91_sys_write(AT91_SMC_MODE(cs), mode);
70
71static void set_smc_timings(const u8 chipselect, const u16 cycle,
72 const u16 setup, const u16 pulse,
73 const u16 data_float, int use_iordy)
74{
75 unsigned long mode = AT91_SMC_READMODE | AT91_SMC_WRITEMODE |
76 AT91_SMC_BAT_SELECT;
77
78 /* disable or enable waiting for IORDY signal */
79 if (use_iordy)
80 mode |= AT91_SMC_EXNWMODE_READY;
81
82 /* add data float cycles if needed */
83 if (data_float)
84 mode |= AT91_SMC_TDF_(data_float);
85
86 at91_sys_write(AT91_SMC_MODE(chipselect), mode);
87
88 /* setup timings in SMC */
89 at91_sys_write(AT91_SMC_SETUP(chipselect), AT91_SMC_NWESETUP_(setup) |
90 AT91_SMC_NCS_WRSETUP_(0) |
91 AT91_SMC_NRDSETUP_(setup) |
92 AT91_SMC_NCS_RDSETUP_(0));
93 at91_sys_write(AT91_SMC_PULSE(chipselect), AT91_SMC_NWEPULSE_(pulse) |
94 AT91_SMC_NCS_WRPULSE_(cycle) |
95 AT91_SMC_NRDPULSE_(pulse) |
96 AT91_SMC_NCS_RDPULSE_(cycle));
97 at91_sys_write(AT91_SMC_CYCLE(chipselect), AT91_SMC_NWECYCLE_(cycle) |
98 AT91_SMC_NRDCYCLE_(cycle));
99}
100
101static unsigned int calc_mck_cycles(unsigned int ns, unsigned int mck_hz)
102{
103 u64 tmp = ns;
104
105 tmp *= mck_hz;
106 tmp += 1000*1000*1000 - 1; /* round up */
107 do_div(tmp, 1000*1000*1000);
108 return (unsigned int) tmp;
109}
110
111static void apply_timings(const u8 chipselect, const u8 pio,
112 const struct ide_timing *timing, int use_iordy)
113{
114 unsigned int t0, t1, t2, t6z;
115 unsigned int cycle, setup, pulse, data_float;
116 unsigned int mck_hz;
117 struct clk *mck;
118
119 /* see table 22 of Compact Flash standard 4.1 for the meaning,
120 * we do not stretch active (t2) time, so setup (t1) + hold time (th)
121 * assure at least minimal recovery (t2i) time */
122 t0 = timing->cyc8b;
123 t1 = timing->setup;
124 t2 = timing->act8b;
125 t6z = (pio < 5) ? 30 : 20;
126
127 pdbg("t0=%u t1=%u t2=%u t6z=%u\n", t0, t1, t2, t6z);
128
129 mck = clk_get(NULL, "mck");
130 BUG_ON(IS_ERR(mck));
131 mck_hz = clk_get_rate(mck);
132 pdbg("mck_hz=%u\n", mck_hz);
133
134 cycle = calc_mck_cycles(t0, mck_hz);
135 setup = calc_mck_cycles(t1, mck_hz);
136 pulse = calc_mck_cycles(t2, mck_hz);
137 data_float = calc_mck_cycles(t6z, mck_hz);
138
139 pdbg("cycle=%u setup=%u pulse=%u data_float=%u\n",
140 cycle, setup, pulse, data_float);
141
142 set_smc_timings(chipselect, cycle, setup, pulse, data_float, use_iordy);
143}
144
adb1af98 145static void at91_ide_input_data(ide_drive_t *drive, struct ide_cmd *cmd,
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146 void *buf, unsigned int len)
147{
148 ide_hwif_t *hwif = drive->hwif;
149 struct ide_io_ports *io_ports = &hwif->io_ports;
150 u8 chipselect = hwif->select_data;
151 unsigned long mode;
152
153 pdbg("cs %u buf %p len %d\n", chipselect, buf, len);
154
155 len++;
156
157 enter_16bit(chipselect, mode);
443d18c8 158 readsw((void __iomem *)io_ports->data_addr, buf, len / 2);
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159 leave_16bit(chipselect, mode);
160}
161
adb1af98 162static void at91_ide_output_data(ide_drive_t *drive, struct ide_cmd *cmd,
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163 void *buf, unsigned int len)
164{
165 ide_hwif_t *hwif = drive->hwif;
166 struct ide_io_ports *io_ports = &hwif->io_ports;
167 u8 chipselect = hwif->select_data;
168 unsigned long mode;
169
170 pdbg("cs %u buf %p len %d\n", chipselect, buf, len);
171
172 enter_16bit(chipselect, mode);
443d18c8 173 writesw((void __iomem *)io_ports->data_addr, buf, len / 2);
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174 leave_16bit(chipselect, mode);
175}
176
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177static void at91_ide_set_pio_mode(ide_drive_t *drive, const u8 pio)
178{
179 struct ide_timing *timing;
180 u8 chipselect = drive->hwif->select_data;
181 int use_iordy = 0;
182
183 pdbg("chipselect %u pio %u\n", chipselect, pio);
184
185 timing = ide_timing_find_mode(XFER_PIO_0 + pio);
186 BUG_ON(!timing);
187
c9ef59ff 188 if (ide_pio_need_iordy(drive, pio))
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189 use_iordy = 1;
190
191 apply_timings(chipselect, pio, timing, use_iordy);
192}
193
194static const struct ide_tp_ops at91_ide_tp_ops = {
195 .exec_command = ide_exec_command,
196 .read_status = ide_read_status,
197 .read_altstatus = ide_read_altstatus,
ecf3a31d 198 .write_devctl = ide_write_devctl,
6e5f1e11 199
abb596b2 200 .dev_select = ide_dev_select,
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201 .tf_load = ide_tf_load,
202 .tf_read = ide_tf_read,
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203
204 .input_data = at91_ide_input_data,
205 .output_data = at91_ide_output_data,
206};
207
208static const struct ide_port_ops at91_ide_port_ops = {
209 .set_pio_mode = at91_ide_set_pio_mode,
210};
211
212static const struct ide_port_info at91_ide_port_info __initdata = {
213 .port_ops = &at91_ide_port_ops,
214 .tp_ops = &at91_ide_tp_ops,
215 .host_flags = IDE_HFLAG_MMIO | IDE_HFLAG_NO_DMA | IDE_HFLAG_SINGLE |
216 IDE_HFLAG_NO_IO_32BIT | IDE_HFLAG_UNMASK_IRQS,
fb4252e5 217 .pio_mask = ATA_PIO6,
29e52cf7 218 .chipset = ide_generic,
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219};
220
221/*
222 * If interrupt is delivered through GPIO, IRQ are triggered on falling
223 * and rising edge of signal. Whereas IDE device request interrupt on high
224 * level (rising edge in our case). This mean we have fake interrupts, so
225 * we need to check interrupt pin and exit instantly from ISR when line
226 * is on low level.
227 */
228
229irqreturn_t at91_irq_handler(int irq, void *dev_id)
230{
231 int ntries = 8;
232 int pin_val1, pin_val2;
233
234 /* additional deglitch, line can be noisy in badly designed PCB */
235 do {
236 pin_val1 = at91_get_gpio_value(irq);
237 pin_val2 = at91_get_gpio_value(irq);
238 } while (pin_val1 != pin_val2 && --ntries > 0);
239
240 if (pin_val1 == 0 || ntries <= 0)
241 return IRQ_HANDLED;
242
243 return ide_intr(irq, dev_id);
244}
245
246static int __init at91_ide_probe(struct platform_device *pdev)
247{
248 int ret;
9f36d314 249 struct ide_hw hw, *hws[] = { &hw };
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250 struct ide_host *host;
251 struct resource *res;
252 unsigned long tf_base = 0, ctl_base = 0;
253 struct at91_cf_data *board = pdev->dev.platform_data;
254
255 if (!board)
256 return -ENODEV;
257
258 if (board->det_pin && at91_get_gpio_value(board->det_pin) != 0) {
259 perr("no device detected\n");
260 return -ENODEV;
261 }
262
263 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
264 if (!res) {
265 perr("can't get memory resource\n");
266 return -ENODEV;
267 }
268
269 if (!devm_request_mem_region(&pdev->dev, res->start + TASK_FILE,
270 REGS_SIZE, "ide") ||
271 !devm_request_mem_region(&pdev->dev, res->start + ALT_MODE,
272 REGS_SIZE, "alt")) {
273 perr("memory resources in use\n");
274 return -EBUSY;
275 }
276
277 pdbg("chipselect %u irq %u res %08lx\n", board->chipselect,
278 board->irq_pin, (unsigned long) res->start);
279
280 tf_base = (unsigned long) devm_ioremap(&pdev->dev, res->start + TASK_FILE,
281 REGS_SIZE);
282 ctl_base = (unsigned long) devm_ioremap(&pdev->dev, res->start + ALT_MODE,
283 REGS_SIZE);
284 if (!tf_base || !ctl_base) {
285 perr("can't map memory regions\n");
286 return -EBUSY;
287 }
288
289 memset(&hw, 0, sizeof(hw));
290
291 if (board->flags & AT91_IDE_SWAP_A0_A2) {
292 /* workaround for stupid hardware bug */
293 hw.io_ports.data_addr = tf_base + 0;
294 hw.io_ports.error_addr = tf_base + 4;
295 hw.io_ports.nsect_addr = tf_base + 2;
296 hw.io_ports.lbal_addr = tf_base + 6;
297 hw.io_ports.lbam_addr = tf_base + 1;
298 hw.io_ports.lbah_addr = tf_base + 5;
299 hw.io_ports.device_addr = tf_base + 3;
300 hw.io_ports.command_addr = tf_base + 7;
301 hw.io_ports.ctl_addr = ctl_base + 3;
302 } else
303 ide_std_init_ports(&hw, tf_base, ctl_base + 6);
304
305 hw.irq = board->irq_pin;
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306 hw.dev = &pdev->dev;
307
dca39830 308 host = ide_host_alloc(&at91_ide_port_info, hws, 1);
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309 if (!host) {
310 perr("failed to allocate ide host\n");
311 return -ENOMEM;
312 }
313
314 /* setup Static Memory Controller - PIO 0 as default */
315 apply_timings(board->chipselect, 0, ide_timing_find_mode(XFER_PIO_0), 0);
316
317 /* with GPIO interrupt we have to do quirks in handler */
318 if (board->irq_pin >= PIN_BASE)
319 host->irq_handler = at91_irq_handler;
320
321 host->ports[0]->select_data = board->chipselect;
322
323 ret = ide_host_register(host, &at91_ide_port_info, hws);
324 if (ret) {
325 perr("failed to register ide host\n");
326 goto err_free_host;
327 }
328 platform_set_drvdata(pdev, host);
329 return 0;
330
331err_free_host:
332 ide_host_free(host);
333 return ret;
334}
335
336static int __exit at91_ide_remove(struct platform_device *pdev)
337{
338 struct ide_host *host = platform_get_drvdata(pdev);
339
340 ide_host_remove(host);
341 return 0;
342}
343
344static struct platform_driver at91_ide_driver = {
345 .driver = {
346 .name = DRV_NAME,
347 .owner = THIS_MODULE,
348 },
349 .remove = __exit_p(at91_ide_remove),
350};
351
352static int __init at91_ide_init(void)
353{
354 return platform_driver_probe(&at91_ide_driver, at91_ide_probe);
355}
356
357static void __exit at91_ide_exit(void)
358{
359 platform_driver_unregister(&at91_ide_driver);
360}
361
362module_init(at91_ide_init);
363module_exit(at91_ide_exit);
364
365MODULE_LICENSE("GPL");
366MODULE_AUTHOR("Stanislaw Gruszka <stf_xl@wp.pl>");
367