xref: /openbmc/linux/drivers/input/serio/sun4i-ps2.c (revision 151f4e2b) 
1 /*
2  *	Driver for Allwinner A10 PS2 host controller
3  *
4  *	Author: Vishnu Patekar <vishnupatekar0510@gmail.com>
5  *		Aaron.maoye <leafy.myeh@newbietech.com>
6  */
7 
8 #include <linux/module.h>
9 #include <linux/serio.h>
10 #include <linux/interrupt.h>
11 #include <linux/errno.h>
12 #include <linux/slab.h>
13 #include <linux/io.h>
14 #include <linux/clk.h>
15 #include <linux/mod_devicetable.h>
16 #include <linux/platform_device.h>
17 
18 #define DRIVER_NAME		"sun4i-ps2"
19 
20 /* register offset definitions */
21 #define PS2_REG_GCTL		0x00	/* PS2 Module Global Control Reg */
22 #define PS2_REG_DATA		0x04	/* PS2 Module Data Reg		*/
23 #define PS2_REG_LCTL		0x08	/* PS2 Module Line Control Reg */
24 #define PS2_REG_LSTS		0x0C	/* PS2 Module Line Status Reg	*/
25 #define PS2_REG_FCTL		0x10	/* PS2 Module FIFO Control Reg */
26 #define PS2_REG_FSTS		0x14	/* PS2 Module FIFO Status Reg	*/
27 #define PS2_REG_CLKDR		0x18	/* PS2 Module Clock Divider Reg*/
28 
29 /*  PS2 GLOBAL CONTROL REGISTER PS2_GCTL */
30 #define PS2_GCTL_INTFLAG	BIT(4)
31 #define PS2_GCTL_INTEN		BIT(3)
32 #define PS2_GCTL_RESET		BIT(2)
33 #define PS2_GCTL_MASTER		BIT(1)
34 #define PS2_GCTL_BUSEN		BIT(0)
35 
36 /* PS2 LINE CONTROL REGISTER */
37 #define PS2_LCTL_NOACK		BIT(18)
38 #define PS2_LCTL_TXDTOEN	BIT(8)
39 #define PS2_LCTL_STOPERREN	BIT(3)
40 #define PS2_LCTL_ACKERREN	BIT(2)
41 #define PS2_LCTL_PARERREN	BIT(1)
42 #define PS2_LCTL_RXDTOEN	BIT(0)
43 
44 /* PS2 LINE STATUS REGISTER */
45 #define PS2_LSTS_TXTDO		BIT(8)
46 #define PS2_LSTS_STOPERR	BIT(3)
47 #define PS2_LSTS_ACKERR		BIT(2)
48 #define PS2_LSTS_PARERR		BIT(1)
49 #define PS2_LSTS_RXTDO		BIT(0)
50 
51 #define PS2_LINE_ERROR_BIT \
52 	(PS2_LSTS_TXTDO | PS2_LSTS_STOPERR | PS2_LSTS_ACKERR | \
53 	PS2_LSTS_PARERR | PS2_LSTS_RXTDO)
54 
55 /* PS2 FIFO CONTROL REGISTER */
56 #define PS2_FCTL_TXRST		BIT(17)
57 #define PS2_FCTL_RXRST		BIT(16)
58 #define PS2_FCTL_TXUFIEN	BIT(10)
59 #define PS2_FCTL_TXOFIEN	BIT(9)
60 #define PS2_FCTL_TXRDYIEN	BIT(8)
61 #define PS2_FCTL_RXUFIEN	BIT(2)
62 #define PS2_FCTL_RXOFIEN	BIT(1)
63 #define PS2_FCTL_RXRDYIEN	BIT(0)
64 
65 /* PS2 FIFO STATUS REGISTER */
66 #define PS2_FSTS_TXUF		BIT(10)
67 #define PS2_FSTS_TXOF		BIT(9)
68 #define PS2_FSTS_TXRDY		BIT(8)
69 #define PS2_FSTS_RXUF		BIT(2)
70 #define PS2_FSTS_RXOF		BIT(1)
71 #define PS2_FSTS_RXRDY		BIT(0)
72 
73 #define PS2_FIFO_ERROR_BIT \
74 	(PS2_FSTS_TXUF | PS2_FSTS_TXOF | PS2_FSTS_RXUF | PS2_FSTS_RXOF)
75 
76 #define PS2_SAMPLE_CLK		1000000
77 #define PS2_SCLK		125000
78 
79 struct sun4i_ps2data {
80 	struct serio *serio;
81 	struct device *dev;
82 
83 	/* IO mapping base */
84 	void __iomem	*reg_base;
85 
86 	/* clock management */
87 	struct clk	*clk;
88 
89 	/* irq */
90 	spinlock_t	lock;
91 	int		irq;
92 };
93 
94 static irqreturn_t sun4i_ps2_interrupt(int irq, void *dev_id)
95 {
96 	struct sun4i_ps2data *drvdata = dev_id;
97 	u32 intr_status;
98 	u32 fifo_status;
99 	unsigned char byte;
100 	unsigned int rxflags = 0;
101 	u32 rval;
102 
103 	spin_lock(&drvdata->lock);
104 
105 	/* Get the PS/2 interrupts and clear them */
106 	intr_status  = readl(drvdata->reg_base + PS2_REG_LSTS);
107 	fifo_status  = readl(drvdata->reg_base + PS2_REG_FSTS);
108 
109 	/* Check line status register */
110 	if (intr_status & PS2_LINE_ERROR_BIT) {
111 		rxflags = (intr_status & PS2_LINE_ERROR_BIT) ? SERIO_FRAME : 0;
112 		rxflags |= (intr_status & PS2_LSTS_PARERR) ? SERIO_PARITY : 0;
113 		rxflags |= (intr_status & PS2_LSTS_PARERR) ? SERIO_TIMEOUT : 0;
114 
115 		rval = PS2_LSTS_TXTDO | PS2_LSTS_STOPERR | PS2_LSTS_ACKERR |
116 			PS2_LSTS_PARERR | PS2_LSTS_RXTDO;
117 		writel(rval, drvdata->reg_base + PS2_REG_LSTS);
118 	}
119 
120 	/* Check FIFO status register */
121 	if (fifo_status & PS2_FIFO_ERROR_BIT) {
122 		rval = PS2_FSTS_TXUF | PS2_FSTS_TXOF | PS2_FSTS_TXRDY |
123 			PS2_FSTS_RXUF | PS2_FSTS_RXOF | PS2_FSTS_RXRDY;
124 		writel(rval, drvdata->reg_base + PS2_REG_FSTS);
125 	}
126 
127 	rval = (fifo_status >> 16) & 0x3;
128 	while (rval--) {
129 		byte = readl(drvdata->reg_base + PS2_REG_DATA) & 0xff;
130 		serio_interrupt(drvdata->serio, byte, rxflags);
131 	}
132 
133 	writel(intr_status, drvdata->reg_base + PS2_REG_LSTS);
134 	writel(fifo_status, drvdata->reg_base + PS2_REG_FSTS);
135 
136 	spin_unlock(&drvdata->lock);
137 
138 	return IRQ_HANDLED;
139 }
140 
141 static int sun4i_ps2_open(struct serio *serio)
142 {
143 	struct sun4i_ps2data *drvdata = serio->port_data;
144 	u32 src_clk = 0;
145 	u32 clk_scdf;
146 	u32 clk_pcdf;
147 	u32 rval;
148 	unsigned long flags;
149 
150 	/* Set line control and enable interrupt */
151 	rval = PS2_LCTL_STOPERREN | PS2_LCTL_ACKERREN
152 		| PS2_LCTL_PARERREN | PS2_LCTL_RXDTOEN;
153 	writel(rval, drvdata->reg_base + PS2_REG_LCTL);
154 
155 	/* Reset FIFO */
156 	rval = PS2_FCTL_TXRST | PS2_FCTL_RXRST | PS2_FCTL_TXUFIEN
157 		| PS2_FCTL_TXOFIEN | PS2_FCTL_RXUFIEN
158 		| PS2_FCTL_RXOFIEN | PS2_FCTL_RXRDYIEN;
159 
160 	writel(rval, drvdata->reg_base + PS2_REG_FCTL);
161 
162 	src_clk = clk_get_rate(drvdata->clk);
163 	/* Set clock divider register */
164 	clk_scdf = src_clk / PS2_SAMPLE_CLK - 1;
165 	clk_pcdf = PS2_SAMPLE_CLK / PS2_SCLK - 1;
166 	rval = (clk_scdf << 8) | clk_pcdf;
167 	writel(rval, drvdata->reg_base + PS2_REG_CLKDR);
168 
169 	/* Set global control register */
170 	rval = PS2_GCTL_RESET | PS2_GCTL_INTEN | PS2_GCTL_MASTER
171 		| PS2_GCTL_BUSEN;
172 
173 	spin_lock_irqsave(&drvdata->lock, flags);
174 	writel(rval, drvdata->reg_base + PS2_REG_GCTL);
175 	spin_unlock_irqrestore(&drvdata->lock, flags);
176 
177 	return 0;
178 }
179 
180 static void sun4i_ps2_close(struct serio *serio)
181 {
182 	struct sun4i_ps2data *drvdata = serio->port_data;
183 	u32 rval;
184 
185 	/* Shut off the interrupt */
186 	rval = readl(drvdata->reg_base + PS2_REG_GCTL);
187 	writel(rval & ~(PS2_GCTL_INTEN), drvdata->reg_base + PS2_REG_GCTL);
188 
189 	synchronize_irq(drvdata->irq);
190 }
191 
192 static int sun4i_ps2_write(struct serio *serio, unsigned char val)
193 {
194 	unsigned long expire = jiffies + msecs_to_jiffies(10000);
195 	struct sun4i_ps2data *drvdata = serio->port_data;
196 
197 	do {
198 		if (readl(drvdata->reg_base + PS2_REG_FSTS) & PS2_FSTS_TXRDY) {
199 			writel(val, drvdata->reg_base + PS2_REG_DATA);
200 			return 0;
201 		}
202 	} while (time_before(jiffies, expire));
203 
204 	return SERIO_TIMEOUT;
205 }
206 
207 static int sun4i_ps2_probe(struct platform_device *pdev)
208 {
209 	struct resource *res; /* IO mem resources */
210 	struct sun4i_ps2data *drvdata;
211 	struct serio *serio;
212 	struct device *dev = &pdev->dev;
213 	unsigned int irq;
214 	int error;
215 
216 	drvdata = kzalloc(sizeof(struct sun4i_ps2data), GFP_KERNEL);
217 	serio = kzalloc(sizeof(struct 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 	strlcpy(serio->name, dev_name(dev), sizeof(serio->name));
260 	strlcpy(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 	irq = platform_get_irq(pdev, 0);
267 	if (!irq) {
268 		dev_err(dev, "no IRQ found\n");
269 		error = -ENXIO;
270 		goto err_disable_clk;
271 	}
272 
273 	drvdata->irq = irq;
274 	drvdata->serio = serio;
275 	drvdata->dev = dev;
276 
277 	error = request_irq(drvdata->irq, sun4i_ps2_interrupt, 0,
278 			    DRIVER_NAME, drvdata);
279 	if (error) {
280 		dev_err(drvdata->dev, "failed to allocate interrupt %d: %d\n",
281 			drvdata->irq, error);
282 		goto err_disable_clk;
283 	}
284 
285 	serio_register_port(serio);
286 	platform_set_drvdata(pdev, drvdata);
287 
288 	return 0;	/* success */
289 
290 err_disable_clk:
291 	clk_disable_unprepare(drvdata->clk);
292 err_clk:
293 	clk_put(drvdata->clk);
294 err_ioremap:
295 	iounmap(drvdata->reg_base);
296 err_free_mem:
297 	kfree(serio);
298 	kfree(drvdata);
299 	return error;
300 }
301 
302 static int sun4i_ps2_remove(struct platform_device *pdev)
303 {
304 	struct sun4i_ps2data *drvdata = platform_get_drvdata(pdev);
305 
306 	serio_unregister_port(drvdata->serio);
307 
308 	free_irq(drvdata->irq, drvdata);
309 
310 	clk_disable_unprepare(drvdata->clk);
311 	clk_put(drvdata->clk);
312 
313 	iounmap(drvdata->reg_base);
314 
315 	kfree(drvdata);
316 
317 	return 0;
318 }
319 
320 static const struct of_device_id sun4i_ps2_match[] = {
321 	{ .compatible = "allwinner,sun4i-a10-ps2", },
322 	{ },
323 };
324 
325 MODULE_DEVICE_TABLE(of, sun4i_ps2_match);
326 
327 static struct platform_driver sun4i_ps2_driver = {
328 	.probe		= sun4i_ps2_probe,
329 	.remove		= sun4i_ps2_remove,
330 	.driver = {
331 		.name = DRIVER_NAME,
332 		.of_match_table = sun4i_ps2_match,
333 	},
334 };
335 module_platform_driver(sun4i_ps2_driver);
336 
337 MODULE_AUTHOR("Vishnu Patekar <vishnupatekar0510@gmail.com>");
338 MODULE_AUTHOR("Aaron.maoye <leafy.myeh@newbietech.com>");
339 MODULE_DESCRIPTION("Allwinner A10/Sun4i PS/2 driver");
340 MODULE_LICENSE("GPL v2");
341