1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Driver for Allwinner A10 PS2 host controller
4 *
5 * Author: Vishnu Patekar <vishnupatekar0510@gmail.com>
6 * Aaron.maoye <leafy.myeh@newbietech.com>
7 */
8
9 #include <linux/module.h>
10 #include <linux/serio.h>
11 #include <linux/interrupt.h>
12 #include <linux/errno.h>
13 #include <linux/slab.h>
14 #include <linux/io.h>
15 #include <linux/clk.h>
16 #include <linux/mod_devicetable.h>
17 #include <linux/platform_device.h>
18
19 #define DRIVER_NAME "sun4i-ps2"
20
21 /* register offset definitions */
22 #define PS2_REG_GCTL 0x00 /* PS2 Module Global Control Reg */
23 #define PS2_REG_DATA 0x04 /* PS2 Module Data Reg */
24 #define PS2_REG_LCTL 0x08 /* PS2 Module Line Control Reg */
25 #define PS2_REG_LSTS 0x0C /* PS2 Module Line Status Reg */
26 #define PS2_REG_FCTL 0x10 /* PS2 Module FIFO Control Reg */
27 #define PS2_REG_FSTS 0x14 /* PS2 Module FIFO Status Reg */
28 #define PS2_REG_CLKDR 0x18 /* PS2 Module Clock Divider Reg*/
29
30 /* PS2 GLOBAL CONTROL REGISTER PS2_GCTL */
31 #define PS2_GCTL_INTFLAG BIT(4)
32 #define PS2_GCTL_INTEN BIT(3)
33 #define PS2_GCTL_RESET BIT(2)
34 #define PS2_GCTL_MASTER BIT(1)
35 #define PS2_GCTL_BUSEN BIT(0)
36
37 /* PS2 LINE CONTROL REGISTER */
38 #define PS2_LCTL_NOACK BIT(18)
39 #define PS2_LCTL_TXDTOEN BIT(8)
40 #define PS2_LCTL_STOPERREN BIT(3)
41 #define PS2_LCTL_ACKERREN BIT(2)
42 #define PS2_LCTL_PARERREN BIT(1)
43 #define PS2_LCTL_RXDTOEN BIT(0)
44
45 /* PS2 LINE STATUS REGISTER */
46 #define PS2_LSTS_TXTDO BIT(8)
47 #define PS2_LSTS_STOPERR BIT(3)
48 #define PS2_LSTS_ACKERR BIT(2)
49 #define PS2_LSTS_PARERR BIT(1)
50 #define PS2_LSTS_RXTDO BIT(0)
51
52 #define PS2_LINE_ERROR_BIT \
53 (PS2_LSTS_TXTDO | PS2_LSTS_STOPERR | PS2_LSTS_ACKERR | \
54 PS2_LSTS_PARERR | PS2_LSTS_RXTDO)
55
56 /* PS2 FIFO CONTROL REGISTER */
57 #define PS2_FCTL_TXRST BIT(17)
58 #define PS2_FCTL_RXRST BIT(16)
59 #define PS2_FCTL_TXUFIEN BIT(10)
60 #define PS2_FCTL_TXOFIEN BIT(9)
61 #define PS2_FCTL_TXRDYIEN BIT(8)
62 #define PS2_FCTL_RXUFIEN BIT(2)
63 #define PS2_FCTL_RXOFIEN BIT(1)
64 #define PS2_FCTL_RXRDYIEN BIT(0)
65
66 /* PS2 FIFO STATUS REGISTER */
67 #define PS2_FSTS_TXUF BIT(10)
68 #define PS2_FSTS_TXOF BIT(9)
69 #define PS2_FSTS_TXRDY BIT(8)
70 #define PS2_FSTS_RXUF BIT(2)
71 #define PS2_FSTS_RXOF BIT(1)
72 #define PS2_FSTS_RXRDY BIT(0)
73
74 #define PS2_FIFO_ERROR_BIT \
75 (PS2_FSTS_TXUF | PS2_FSTS_TXOF | PS2_FSTS_RXUF | PS2_FSTS_RXOF)
76
77 #define PS2_SAMPLE_CLK 1000000
78 #define PS2_SCLK 125000
79
80 struct sun4i_ps2data {
81 struct serio *serio;
82 struct device *dev;
83
84 /* IO mapping base */
85 void __iomem *reg_base;
86
87 /* clock management */
88 struct clk *clk;
89
90 /* irq */
91 spinlock_t lock;
92 int irq;
93 };
94
sun4i_ps2_interrupt(int irq,void * dev_id)95 static irqreturn_t sun4i_ps2_interrupt(int irq, void *dev_id)
96 {
97 struct sun4i_ps2data *drvdata = dev_id;
98 u32 intr_status;
99 u32 fifo_status;
100 unsigned char byte;
101 unsigned int rxflags = 0;
102 u32 rval;
103
104 spin_lock(&drvdata->lock);
105
106 /* Get the PS/2 interrupts and clear them */
107 intr_status = readl(drvdata->reg_base + PS2_REG_LSTS);
108 fifo_status = readl(drvdata->reg_base + PS2_REG_FSTS);
109
110 /* Check line status register */
111 if (intr_status & PS2_LINE_ERROR_BIT) {
112 rxflags = (intr_status & PS2_LINE_ERROR_BIT) ? SERIO_FRAME : 0;
113 rxflags |= (intr_status & PS2_LSTS_PARERR) ? SERIO_PARITY : 0;
114 rxflags |= (intr_status & PS2_LSTS_PARERR) ? SERIO_TIMEOUT : 0;
115
116 rval = PS2_LSTS_TXTDO | PS2_LSTS_STOPERR | PS2_LSTS_ACKERR |
117 PS2_LSTS_PARERR | PS2_LSTS_RXTDO;
118 writel(rval, drvdata->reg_base + PS2_REG_LSTS);
119 }
120
121 /* Check FIFO status register */
122 if (fifo_status & PS2_FIFO_ERROR_BIT) {
123 rval = PS2_FSTS_TXUF | PS2_FSTS_TXOF | PS2_FSTS_TXRDY |
124 PS2_FSTS_RXUF | PS2_FSTS_RXOF | PS2_FSTS_RXRDY;
125 writel(rval, drvdata->reg_base + PS2_REG_FSTS);
126 }
127
128 rval = (fifo_status >> 16) & 0x3;
129 while (rval--) {
130 byte = readl(drvdata->reg_base + PS2_REG_DATA) & 0xff;
131 serio_interrupt(drvdata->serio, byte, rxflags);
132 }
133
134 writel(intr_status, drvdata->reg_base + PS2_REG_LSTS);
135 writel(fifo_status, drvdata->reg_base + PS2_REG_FSTS);
136
137 spin_unlock(&drvdata->lock);
138
139 return IRQ_HANDLED;
140 }
141
sun4i_ps2_open(struct serio * serio)142 static int sun4i_ps2_open(struct serio *serio)
143 {
144 struct sun4i_ps2data *drvdata = serio->port_data;
145 u32 src_clk = 0;
146 u32 clk_scdf;
147 u32 clk_pcdf;
148 u32 rval;
149 unsigned long flags;
150
151 /* Set line control and enable interrupt */
152 rval = PS2_LCTL_STOPERREN | PS2_LCTL_ACKERREN
153 | PS2_LCTL_PARERREN | PS2_LCTL_RXDTOEN;
154 writel(rval, drvdata->reg_base + PS2_REG_LCTL);
155
156 /* Reset FIFO */
157 rval = PS2_FCTL_TXRST | PS2_FCTL_RXRST | PS2_FCTL_TXUFIEN
158 | PS2_FCTL_TXOFIEN | PS2_FCTL_RXUFIEN
159 | PS2_FCTL_RXOFIEN | PS2_FCTL_RXRDYIEN;
160
161 writel(rval, drvdata->reg_base + PS2_REG_FCTL);
162
163 src_clk = clk_get_rate(drvdata->clk);
164 /* Set clock divider register */
165 clk_scdf = src_clk / PS2_SAMPLE_CLK - 1;
166 clk_pcdf = PS2_SAMPLE_CLK / PS2_SCLK - 1;
167 rval = (clk_scdf << 8) | clk_pcdf;
168 writel(rval, drvdata->reg_base + PS2_REG_CLKDR);
169
170 /* Set global control register */
171 rval = PS2_GCTL_RESET | PS2_GCTL_INTEN | PS2_GCTL_MASTER
172 | PS2_GCTL_BUSEN;
173
174 spin_lock_irqsave(&drvdata->lock, flags);
175 writel(rval, drvdata->reg_base + PS2_REG_GCTL);
176 spin_unlock_irqrestore(&drvdata->lock, flags);
177
178 return 0;
179 }
180
sun4i_ps2_close(struct serio * serio)181 static void sun4i_ps2_close(struct serio *serio)
182 {
183 struct sun4i_ps2data *drvdata = serio->port_data;
184 u32 rval;
185
186 /* Shut off the interrupt */
187 rval = readl(drvdata->reg_base + PS2_REG_GCTL);
188 writel(rval & ~(PS2_GCTL_INTEN), drvdata->reg_base + PS2_REG_GCTL);
189
190 synchronize_irq(drvdata->irq);
191 }
192
sun4i_ps2_write(struct serio * serio,unsigned char val)193 static int sun4i_ps2_write(struct serio *serio, unsigned char val)
194 {
195 unsigned long expire = jiffies + msecs_to_jiffies(10000);
196 struct sun4i_ps2data *drvdata = serio->port_data;
197
198 do {
199 if (readl(drvdata->reg_base + PS2_REG_FSTS) & PS2_FSTS_TXRDY) {
200 writel(val, drvdata->reg_base + PS2_REG_DATA);
201 return 0;
202 }
203 } while (time_before(jiffies, expire));
204
205 return SERIO_TIMEOUT;
206 }
207
sun4i_ps2_probe(struct platform_device * pdev)208 static int sun4i_ps2_probe(struct platform_device *pdev)
209 {
210 struct resource *res; /* IO mem resources */
211 struct sun4i_ps2data *drvdata;
212 struct serio *serio;
213 struct device *dev = &pdev->dev;
214 int error;
215
216 drvdata = kzalloc(sizeof(*drvdata), GFP_KERNEL);
217 serio = kzalloc(sizeof(*serio), GFP_KERNEL);
218 if (!drvdata || !serio) {
219 error = -ENOMEM;
220 goto err_free_mem;
221 }
222
223 spin_lock_init(&drvdata->lock);
224
225 /* IO */
226 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
227 if (!res) {
228 dev_err(dev, "failed to locate registers\n");
229 error = -ENXIO;
230 goto err_free_mem;
231 }
232
233 drvdata->reg_base = ioremap(res->start, resource_size(res));
234 if (!drvdata->reg_base) {
235 dev_err(dev, "failed to map registers\n");
236 error = -ENOMEM;
237 goto err_free_mem;
238 }
239
240 drvdata->clk = clk_get(dev, NULL);
241 if (IS_ERR(drvdata->clk)) {
242 error = PTR_ERR(drvdata->clk);
243 dev_err(dev, "couldn't get clock %d\n", error);
244 goto err_ioremap;
245 }
246
247 error = clk_prepare_enable(drvdata->clk);
248 if (error) {
249 dev_err(dev, "failed to enable clock %d\n", error);
250 goto err_clk;
251 }
252
253 serio->id.type = SERIO_8042;
254 serio->write = sun4i_ps2_write;
255 serio->open = sun4i_ps2_open;
256 serio->close = sun4i_ps2_close;
257 serio->port_data = drvdata;
258 serio->dev.parent = dev;
259 strscpy(serio->name, dev_name(dev), sizeof(serio->name));
260 strscpy(serio->phys, dev_name(dev), sizeof(serio->phys));
261
262 /* shutoff interrupt */
263 writel(0, drvdata->reg_base + PS2_REG_GCTL);
264
265 /* Get IRQ for the device */
266 drvdata->irq = platform_get_irq(pdev, 0);
267 if (drvdata->irq < 0) {
268 error = drvdata->irq;
269 goto err_disable_clk;
270 }
271
272 drvdata->serio = serio;
273 drvdata->dev = dev;
274
275 error = request_irq(drvdata->irq, sun4i_ps2_interrupt, 0,
276 DRIVER_NAME, drvdata);
277 if (error) {
278 dev_err(drvdata->dev, "failed to allocate interrupt %d: %d\n",
279 drvdata->irq, error);
280 goto err_disable_clk;
281 }
282
283 serio_register_port(serio);
284 platform_set_drvdata(pdev, drvdata);
285
286 return 0; /* success */
287
288 err_disable_clk:
289 clk_disable_unprepare(drvdata->clk);
290 err_clk:
291 clk_put(drvdata->clk);
292 err_ioremap:
293 iounmap(drvdata->reg_base);
294 err_free_mem:
295 kfree(serio);
296 kfree(drvdata);
297 return error;
298 }
299
sun4i_ps2_remove(struct platform_device * pdev)300 static void sun4i_ps2_remove(struct platform_device *pdev)
301 {
302 struct sun4i_ps2data *drvdata = platform_get_drvdata(pdev);
303
304 serio_unregister_port(drvdata->serio);
305
306 free_irq(drvdata->irq, drvdata);
307
308 clk_disable_unprepare(drvdata->clk);
309 clk_put(drvdata->clk);
310
311 iounmap(drvdata->reg_base);
312
313 kfree(drvdata);
314 }
315
316 static const struct of_device_id sun4i_ps2_match[] = {
317 { .compatible = "allwinner,sun4i-a10-ps2", },
318 { },
319 };
320
321 MODULE_DEVICE_TABLE(of, sun4i_ps2_match);
322
323 static struct platform_driver sun4i_ps2_driver = {
324 .probe = sun4i_ps2_probe,
325 .remove_new = sun4i_ps2_remove,
326 .driver = {
327 .name = DRIVER_NAME,
328 .of_match_table = sun4i_ps2_match,
329 },
330 };
331 module_platform_driver(sun4i_ps2_driver);
332
333 MODULE_AUTHOR("Vishnu Patekar <vishnupatekar0510@gmail.com>");
334 MODULE_AUTHOR("Aaron.maoye <leafy.myeh@newbietech.com>");
335 MODULE_DESCRIPTION("Allwinner A10/Sun4i PS/2 driver");
336 MODULE_LICENSE("GPL v2");
337