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1 | /* |
2 | * Copyright (C) 2007 Atmel Corporation | |
3 | * | |
4 | * Driver for the AT32AP700X PS/2 controller (PSIF). | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify it | |
7 | * under the terms of the GNU General Public License version 2 as published | |
8 | * by the Free Software Foundation. | |
9 | */ | |
10 | #include <linux/kernel.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/device.h> | |
13 | #include <linux/init.h> | |
14 | #include <linux/serio.h> | |
15 | #include <linux/interrupt.h> | |
16 | #include <linux/delay.h> | |
17 | #include <linux/err.h> | |
18 | #include <linux/io.h> | |
19 | #include <linux/clk.h> | |
20 | #include <linux/platform_device.h> | |
21 | ||
22 | /* PSIF register offsets */ | |
23 | #define PSIF_CR 0x00 | |
24 | #define PSIF_RHR 0x04 | |
25 | #define PSIF_THR 0x08 | |
26 | #define PSIF_SR 0x10 | |
27 | #define PSIF_IER 0x14 | |
28 | #define PSIF_IDR 0x18 | |
29 | #define PSIF_IMR 0x1c | |
30 | #define PSIF_PSR 0x24 | |
31 | ||
32 | /* Bitfields in control register. */ | |
33 | #define PSIF_CR_RXDIS_OFFSET 1 | |
34 | #define PSIF_CR_RXDIS_SIZE 1 | |
35 | #define PSIF_CR_RXEN_OFFSET 0 | |
36 | #define PSIF_CR_RXEN_SIZE 1 | |
37 | #define PSIF_CR_SWRST_OFFSET 15 | |
38 | #define PSIF_CR_SWRST_SIZE 1 | |
39 | #define PSIF_CR_TXDIS_OFFSET 9 | |
40 | #define PSIF_CR_TXDIS_SIZE 1 | |
41 | #define PSIF_CR_TXEN_OFFSET 8 | |
42 | #define PSIF_CR_TXEN_SIZE 1 | |
43 | ||
44 | /* Bitfields in interrupt disable, enable, mask and status register. */ | |
45 | #define PSIF_NACK_OFFSET 8 | |
46 | #define PSIF_NACK_SIZE 1 | |
47 | #define PSIF_OVRUN_OFFSET 5 | |
48 | #define PSIF_OVRUN_SIZE 1 | |
49 | #define PSIF_PARITY_OFFSET 9 | |
50 | #define PSIF_PARITY_SIZE 1 | |
51 | #define PSIF_RXRDY_OFFSET 4 | |
52 | #define PSIF_RXRDY_SIZE 1 | |
53 | #define PSIF_TXEMPTY_OFFSET 1 | |
54 | #define PSIF_TXEMPTY_SIZE 1 | |
55 | #define PSIF_TXRDY_OFFSET 0 | |
56 | #define PSIF_TXRDY_SIZE 1 | |
57 | ||
58 | /* Bitfields in prescale register. */ | |
59 | #define PSIF_PSR_PRSCV_OFFSET 0 | |
60 | #define PSIF_PSR_PRSCV_SIZE 12 | |
61 | ||
62 | /* Bitfields in receive hold register. */ | |
63 | #define PSIF_RHR_RXDATA_OFFSET 0 | |
64 | #define PSIF_RHR_RXDATA_SIZE 8 | |
65 | ||
66 | /* Bitfields in transmit hold register. */ | |
67 | #define PSIF_THR_TXDATA_OFFSET 0 | |
68 | #define PSIF_THR_TXDATA_SIZE 8 | |
69 | ||
70 | /* Bit manipulation macros */ | |
71 | #define PSIF_BIT(name) \ | |
72 | (1 << PSIF_##name##_OFFSET) | |
73 | ||
74 | #define PSIF_BF(name, value) \ | |
75 | (((value) & ((1 << PSIF_##name##_SIZE) - 1)) \ | |
76 | << PSIF_##name##_OFFSET) | |
77 | ||
78 | #define PSIF_BFEXT(name, value) \ | |
79 | (((value) >> PSIF_##name##_OFFSET) \ | |
80 | & ((1 << PSIF_##name##_SIZE) - 1)) | |
81 | ||
82 | #define PSIF_BFINS(name, value, old) \ | |
83 | (((old) & ~(((1 << PSIF_##name##_SIZE) - 1) \ | |
84 | << PSIF_##name##_OFFSET)) \ | |
85 | | PSIF_BF(name, value)) | |
86 | ||
87 | /* Register access macros */ | |
88 | #define psif_readl(port, reg) \ | |
89 | __raw_readl((port)->regs + PSIF_##reg) | |
90 | ||
91 | #define psif_writel(port, reg, value) \ | |
92 | __raw_writel((value), (port)->regs + PSIF_##reg) | |
93 | ||
94 | struct psif { | |
95 | struct platform_device *pdev; | |
96 | struct clk *pclk; | |
97 | struct serio *io; | |
98 | void __iomem *regs; | |
99 | unsigned int irq; | |
100 | unsigned int open; | |
101 | /* Prevent concurrent writes to PSIF THR. */ | |
102 | spinlock_t lock; | |
103 | }; | |
104 | ||
105 | static irqreturn_t psif_interrupt(int irq, void *_ptr) | |
106 | { | |
107 | struct psif *psif = _ptr; | |
108 | int retval = IRQ_NONE; | |
109 | unsigned int io_flags = 0; | |
110 | unsigned long status; | |
111 | ||
112 | status = psif_readl(psif, SR); | |
113 | ||
114 | if (status & PSIF_BIT(RXRDY)) { | |
115 | unsigned char val = (unsigned char) psif_readl(psif, RHR); | |
116 | ||
117 | if (status & PSIF_BIT(PARITY)) | |
118 | io_flags |= SERIO_PARITY; | |
119 | if (status & PSIF_BIT(OVRUN)) | |
120 | dev_err(&psif->pdev->dev, "overrun read error\n"); | |
121 | ||
122 | serio_interrupt(psif->io, val, io_flags); | |
123 | ||
124 | retval = IRQ_HANDLED; | |
125 | } | |
126 | ||
127 | return retval; | |
128 | } | |
129 | ||
130 | static int psif_write(struct serio *io, unsigned char val) | |
131 | { | |
132 | struct psif *psif = io->port_data; | |
133 | unsigned long flags; | |
134 | int timeout = 10; | |
135 | int retval = 0; | |
136 | ||
137 | spin_lock_irqsave(&psif->lock, flags); | |
138 | ||
139 | while (!(psif_readl(psif, SR) & PSIF_BIT(TXEMPTY)) && timeout--) | |
e47c4f70 | 140 | udelay(50); |
9f9439e9 HCE |
141 | |
142 | if (timeout >= 0) { | |
143 | psif_writel(psif, THR, val); | |
144 | } else { | |
145 | dev_dbg(&psif->pdev->dev, "timeout writing to THR\n"); | |
146 | retval = -EBUSY; | |
147 | } | |
148 | ||
149 | spin_unlock_irqrestore(&psif->lock, flags); | |
150 | ||
151 | return retval; | |
152 | } | |
153 | ||
154 | static int psif_open(struct serio *io) | |
155 | { | |
156 | struct psif *psif = io->port_data; | |
157 | int retval; | |
158 | ||
159 | retval = clk_enable(psif->pclk); | |
160 | if (retval) | |
161 | goto out; | |
162 | ||
163 | psif_writel(psif, CR, PSIF_BIT(CR_TXEN) | PSIF_BIT(CR_RXEN)); | |
164 | psif_writel(psif, IER, PSIF_BIT(RXRDY)); | |
165 | ||
166 | psif->open = 1; | |
167 | out: | |
168 | return retval; | |
169 | } | |
170 | ||
171 | static void psif_close(struct serio *io) | |
172 | { | |
173 | struct psif *psif = io->port_data; | |
174 | ||
175 | psif->open = 0; | |
176 | ||
177 | psif_writel(psif, IDR, ~0UL); | |
178 | psif_writel(psif, CR, PSIF_BIT(CR_TXDIS) | PSIF_BIT(CR_RXDIS)); | |
179 | ||
180 | clk_disable(psif->pclk); | |
181 | } | |
182 | ||
183 | static void psif_set_prescaler(struct psif *psif) | |
184 | { | |
185 | unsigned long prscv; | |
186 | unsigned long rate = clk_get_rate(psif->pclk); | |
187 | ||
188 | /* PRSCV = Pulse length (100 us) * PSIF module frequency. */ | |
189 | prscv = 100 * (rate / 1000000UL); | |
190 | ||
191 | if (prscv > ((1<<PSIF_PSR_PRSCV_SIZE) - 1)) { | |
192 | prscv = (1<<PSIF_PSR_PRSCV_SIZE) - 1; | |
193 | dev_dbg(&psif->pdev->dev, "pclk too fast, " | |
194 | "prescaler set to max\n"); | |
195 | } | |
196 | ||
197 | clk_enable(psif->pclk); | |
198 | psif_writel(psif, PSR, prscv); | |
199 | clk_disable(psif->pclk); | |
200 | } | |
201 | ||
202 | static int __init psif_probe(struct platform_device *pdev) | |
203 | { | |
204 | struct resource *regs; | |
205 | struct psif *psif; | |
206 | struct serio *io; | |
207 | struct clk *pclk; | |
208 | int irq; | |
209 | int ret; | |
210 | ||
211 | psif = kzalloc(sizeof(struct psif), GFP_KERNEL); | |
212 | if (!psif) { | |
213 | dev_dbg(&pdev->dev, "out of memory\n"); | |
214 | ret = -ENOMEM; | |
215 | goto out; | |
216 | } | |
217 | psif->pdev = pdev; | |
218 | ||
219 | io = kzalloc(sizeof(struct serio), GFP_KERNEL); | |
220 | if (!io) { | |
221 | dev_dbg(&pdev->dev, "out of memory\n"); | |
222 | ret = -ENOMEM; | |
223 | goto out_free_psif; | |
224 | } | |
225 | psif->io = io; | |
226 | ||
227 | regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
228 | if (!regs) { | |
229 | dev_dbg(&pdev->dev, "no mmio resources defined\n"); | |
230 | ret = -ENOMEM; | |
231 | goto out_free_io; | |
232 | } | |
233 | ||
72398e4b | 234 | psif->regs = ioremap(regs->start, resource_size(regs)); |
9f9439e9 HCE |
235 | if (!psif->regs) { |
236 | ret = -ENOMEM; | |
237 | dev_dbg(&pdev->dev, "could not map I/O memory\n"); | |
238 | goto out_free_io; | |
239 | } | |
240 | ||
241 | pclk = clk_get(&pdev->dev, "pclk"); | |
242 | if (IS_ERR(pclk)) { | |
243 | dev_dbg(&pdev->dev, "could not get peripheral clock\n"); | |
244 | ret = PTR_ERR(pclk); | |
245 | goto out_iounmap; | |
246 | } | |
247 | psif->pclk = pclk; | |
248 | ||
249 | /* Reset the PSIF to enter at a known state. */ | |
250 | ret = clk_enable(pclk); | |
251 | if (ret) { | |
252 | dev_dbg(&pdev->dev, "could not enable pclk\n"); | |
253 | goto out_put_clk; | |
254 | } | |
255 | psif_writel(psif, CR, PSIF_BIT(CR_SWRST)); | |
256 | clk_disable(pclk); | |
257 | ||
258 | irq = platform_get_irq(pdev, 0); | |
259 | if (irq < 0) { | |
260 | dev_dbg(&pdev->dev, "could not get irq\n"); | |
261 | ret = -ENXIO; | |
262 | goto out_put_clk; | |
263 | } | |
264 | ret = request_irq(irq, psif_interrupt, IRQF_SHARED, "at32psif", psif); | |
265 | if (ret) { | |
266 | dev_dbg(&pdev->dev, "could not request irq %d\n", irq); | |
267 | goto out_put_clk; | |
268 | } | |
269 | psif->irq = irq; | |
270 | ||
271 | io->id.type = SERIO_8042; | |
272 | io->write = psif_write; | |
273 | io->open = psif_open; | |
274 | io->close = psif_close; | |
275 | snprintf(io->name, sizeof(io->name), "AVR32 PS/2 port%d", pdev->id); | |
276 | snprintf(io->phys, sizeof(io->phys), "at32psif/serio%d", pdev->id); | |
277 | io->port_data = psif; | |
278 | io->dev.parent = &pdev->dev; | |
279 | ||
280 | psif_set_prescaler(psif); | |
281 | ||
282 | spin_lock_init(&psif->lock); | |
283 | serio_register_port(psif->io); | |
284 | platform_set_drvdata(pdev, psif); | |
285 | ||
286 | dev_info(&pdev->dev, "Atmel AVR32 PSIF PS/2 driver on 0x%08x irq %d\n", | |
287 | (int)psif->regs, psif->irq); | |
288 | ||
289 | return 0; | |
290 | ||
291 | out_put_clk: | |
292 | clk_put(psif->pclk); | |
293 | out_iounmap: | |
294 | iounmap(psif->regs); | |
295 | out_free_io: | |
296 | kfree(io); | |
297 | out_free_psif: | |
298 | kfree(psif); | |
299 | out: | |
300 | return ret; | |
301 | } | |
302 | ||
303 | static int __exit psif_remove(struct platform_device *pdev) | |
304 | { | |
305 | struct psif *psif = platform_get_drvdata(pdev); | |
306 | ||
307 | psif_writel(psif, IDR, ~0UL); | |
308 | psif_writel(psif, CR, PSIF_BIT(CR_TXDIS) | PSIF_BIT(CR_RXDIS)); | |
309 | ||
310 | serio_unregister_port(psif->io); | |
311 | iounmap(psif->regs); | |
312 | free_irq(psif->irq, psif); | |
313 | clk_put(psif->pclk); | |
314 | kfree(psif); | |
315 | ||
316 | platform_set_drvdata(pdev, NULL); | |
317 | ||
318 | return 0; | |
319 | } | |
320 | ||
321 | #ifdef CONFIG_PM | |
322 | static int psif_suspend(struct platform_device *pdev, pm_message_t state) | |
323 | { | |
324 | struct psif *psif = platform_get_drvdata(pdev); | |
325 | ||
326 | if (psif->open) { | |
327 | psif_writel(psif, CR, PSIF_BIT(CR_RXDIS) | PSIF_BIT(CR_TXDIS)); | |
328 | clk_disable(psif->pclk); | |
329 | } | |
330 | ||
331 | return 0; | |
332 | } | |
333 | ||
334 | static int psif_resume(struct platform_device *pdev) | |
335 | { | |
336 | struct psif *psif = platform_get_drvdata(pdev); | |
337 | ||
338 | if (psif->open) { | |
339 | clk_enable(psif->pclk); | |
340 | psif_set_prescaler(psif); | |
341 | psif_writel(psif, CR, PSIF_BIT(CR_RXEN) | PSIF_BIT(CR_TXEN)); | |
342 | } | |
343 | ||
344 | return 0; | |
345 | } | |
346 | #else | |
347 | #define psif_suspend NULL | |
348 | #define psif_resume NULL | |
349 | #endif | |
350 | ||
351 | static struct platform_driver psif_driver = { | |
352 | .remove = __exit_p(psif_remove), | |
353 | .driver = { | |
354 | .name = "atmel_psif", | |
898d1053 | 355 | .owner = THIS_MODULE, |
9f9439e9 HCE |
356 | }, |
357 | .suspend = psif_suspend, | |
358 | .resume = psif_resume, | |
359 | }; | |
360 | ||
361 | static int __init psif_init(void) | |
362 | { | |
363 | return platform_driver_probe(&psif_driver, psif_probe); | |
364 | } | |
365 | ||
366 | static void __exit psif_exit(void) | |
367 | { | |
368 | platform_driver_unregister(&psif_driver); | |
369 | } | |
370 | ||
371 | module_init(psif_init); | |
372 | module_exit(psif_exit); | |
373 | ||
a22b4b2f | 374 | MODULE_AUTHOR("Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>"); |
9f9439e9 HCE |
375 | MODULE_DESCRIPTION("Atmel AVR32 PSIF PS/2 driver"); |
376 | MODULE_LICENSE("GPL"); |