xref: /openbmc/u-boot/drivers/i2c/sh_i2c.c (revision e11ef3d2)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2011, 2013 Renesas Solutions Corp.
4  * Copyright (C) 2011, 2013 Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
5  *
6  * NOTE: This driver should be converted to driver model before June 2017.
7  * Please see doc/driver-model/i2c-howto.txt for instructions.
8  */
9 
10 #include <common.h>
11 #include <i2c.h>
12 #include <asm/io.h>
13 
14 DECLARE_GLOBAL_DATA_PTR;
15 
16 /* Every register is 32bit aligned, but only 8bits in size */
17 #define ureg(name) u8 name; u8 __pad_##name##0; u16 __pad_##name##1;
18 struct sh_i2c {
19 	ureg(icdr);
20 	ureg(iccr);
21 	ureg(icsr);
22 	ureg(icic);
23 	ureg(iccl);
24 	ureg(icch);
25 };
26 #undef ureg
27 
28 /* ICCR */
29 #define SH_I2C_ICCR_ICE		(1 << 7)
30 #define SH_I2C_ICCR_RACK	(1 << 6)
31 #define SH_I2C_ICCR_RTS		(1 << 4)
32 #define SH_I2C_ICCR_BUSY	(1 << 2)
33 #define SH_I2C_ICCR_SCP		(1 << 0)
34 
35 /* ICSR / ICIC */
36 #define SH_IC_BUSY	(1 << 4)
37 #define SH_IC_TACK	(1 << 2)
38 #define SH_IC_WAIT	(1 << 1)
39 #define SH_IC_DTE	(1 << 0)
40 
41 #ifdef CONFIG_SH_I2C_8BIT
42 /* store 8th bit of iccl and icch in ICIC register */
43 #define SH_I2C_ICIC_ICCLB8	(1 << 7)
44 #define SH_I2C_ICIC_ICCHB8	(1 << 6)
45 #endif
46 
47 static const struct sh_i2c *i2c_dev[CONFIG_SYS_I2C_SH_NUM_CONTROLLERS] = {
48 	(struct sh_i2c *)CONFIG_SYS_I2C_SH_BASE0,
49 #ifdef CONFIG_SYS_I2C_SH_BASE1
50 	(struct sh_i2c *)CONFIG_SYS_I2C_SH_BASE1,
51 #endif
52 #ifdef CONFIG_SYS_I2C_SH_BASE2
53 	(struct sh_i2c *)CONFIG_SYS_I2C_SH_BASE2,
54 #endif
55 #ifdef CONFIG_SYS_I2C_SH_BASE3
56 	(struct sh_i2c *)CONFIG_SYS_I2C_SH_BASE3,
57 #endif
58 #ifdef CONFIG_SYS_I2C_SH_BASE4
59 	(struct sh_i2c *)CONFIG_SYS_I2C_SH_BASE4,
60 #endif
61 };
62 
63 static u16 iccl, icch;
64 
65 #define IRQ_WAIT 1000
66 
67 static void sh_irq_dte(struct sh_i2c *dev)
68 {
69 	int i;
70 
71 	for (i = 0; i < IRQ_WAIT; i++) {
72 		if (SH_IC_DTE & readb(&dev->icsr))
73 			break;
74 		udelay(10);
75 	}
76 }
77 
78 static int sh_irq_dte_with_tack(struct sh_i2c *dev)
79 {
80 	int i;
81 
82 	for (i = 0; i < IRQ_WAIT; i++) {
83 		if (SH_IC_DTE & readb(&dev->icsr))
84 			break;
85 		if (SH_IC_TACK & readb(&dev->icsr))
86 			return -1;
87 		udelay(10);
88 	}
89 	return 0;
90 }
91 
92 static void sh_irq_busy(struct sh_i2c *dev)
93 {
94 	int i;
95 
96 	for (i = 0; i < IRQ_WAIT; i++) {
97 		if (!(SH_IC_BUSY & readb(&dev->icsr)))
98 			break;
99 		udelay(10);
100 	}
101 }
102 
103 static int sh_i2c_set_addr(struct sh_i2c *dev, u8 chip, u8 addr, int stop)
104 {
105 	u8 icic = SH_IC_TACK;
106 
107 	debug("%s: chip: %x, addr: %x iccl: %x, icch %x\n",
108 				__func__, chip, addr, iccl, icch);
109 	clrbits_8(&dev->iccr, SH_I2C_ICCR_ICE);
110 	setbits_8(&dev->iccr, SH_I2C_ICCR_ICE);
111 
112 	writeb(iccl & 0xff, &dev->iccl);
113 	writeb(icch & 0xff, &dev->icch);
114 #ifdef CONFIG_SH_I2C_8BIT
115 	if (iccl > 0xff)
116 		icic |= SH_I2C_ICIC_ICCLB8;
117 	if (icch > 0xff)
118 		icic |= SH_I2C_ICIC_ICCHB8;
119 #endif
120 	writeb(icic, &dev->icic);
121 
122 	writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_RTS|SH_I2C_ICCR_BUSY), &dev->iccr);
123 	sh_irq_dte(dev);
124 
125 	clrbits_8(&dev->icsr, SH_IC_TACK);
126 	writeb(chip << 1, &dev->icdr);
127 	if (sh_irq_dte_with_tack(dev) != 0)
128 		return -1;
129 
130 	writeb(addr, &dev->icdr);
131 	if (stop)
132 		writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_RTS), &dev->iccr);
133 
134 	if (sh_irq_dte_with_tack(dev) != 0)
135 		return -1;
136 	return 0;
137 }
138 
139 static void sh_i2c_finish(struct sh_i2c *dev)
140 {
141 	writeb(0, &dev->icsr);
142 	clrbits_8(&dev->iccr, SH_I2C_ICCR_ICE);
143 }
144 
145 static int
146 sh_i2c_raw_write(struct sh_i2c *dev, u8 chip, uint addr, u8 val)
147 {
148 	int ret = -1;
149 	if (sh_i2c_set_addr(dev, chip, addr, 0) != 0)
150 		goto exit0;
151 	udelay(10);
152 
153 	writeb(val, &dev->icdr);
154 	if (sh_irq_dte_with_tack(dev) != 0)
155 		goto exit0;
156 
157 	writeb((SH_I2C_ICCR_ICE | SH_I2C_ICCR_RTS), &dev->iccr);
158 	if (sh_irq_dte_with_tack(dev) != 0)
159 		goto exit0;
160 	sh_irq_busy(dev);
161 	ret = 0;
162 
163 exit0:
164 	sh_i2c_finish(dev);
165 	return ret;
166 }
167 
168 static int sh_i2c_raw_read(struct sh_i2c *dev, u8 chip, u8 addr)
169 {
170 	int ret = -1;
171 
172 #if defined(CONFIG_SH73A0)
173 	if (sh_i2c_set_addr(dev, chip, addr, 0) != 0)
174 		goto exit0;
175 #else
176 	if (sh_i2c_set_addr(dev, chip, addr, 1) != 0)
177 		goto exit0;
178 	udelay(100);
179 #endif
180 
181 	writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_RTS|SH_I2C_ICCR_BUSY), &dev->iccr);
182 	sh_irq_dte(dev);
183 
184 	writeb(chip << 1 | 0x01, &dev->icdr);
185 	if (sh_irq_dte_with_tack(dev) != 0)
186 		goto exit0;
187 
188 	writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_SCP), &dev->iccr);
189 	if (sh_irq_dte_with_tack(dev) != 0)
190 		goto exit0;
191 
192 	ret = readb(&dev->icdr) & 0xff;
193 
194 	writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_RACK), &dev->iccr);
195 	readb(&dev->icdr); /* Dummy read */
196 	sh_irq_busy(dev);
197 
198 exit0:
199 	sh_i2c_finish(dev);
200 
201 	return ret;
202 }
203 
204 static void
205 sh_i2c_init(struct i2c_adapter *adap, int speed, int slaveadd)
206 {
207 	int num, denom, tmp;
208 
209 	/* No i2c support prior to relocation */
210 	if (!(gd->flags & GD_FLG_RELOC))
211 		return;
212 
213 	/*
214 	 * Calculate the value for iccl. From the data sheet:
215 	 * iccl = (p-clock / transfer-rate) * (L / (L + H))
216 	 * where L and H are the SCL low and high ratio.
217 	 */
218 	num = CONFIG_SH_I2C_CLOCK * CONFIG_SH_I2C_DATA_LOW;
219 	denom = speed * (CONFIG_SH_I2C_DATA_HIGH + CONFIG_SH_I2C_DATA_LOW);
220 	tmp = num * 10 / denom;
221 	if (tmp % 10 >= 5)
222 		iccl = (u16)((num/denom) + 1);
223 	else
224 		iccl = (u16)(num/denom);
225 
226 	/* Calculate the value for icch. From the data sheet:
227 	   icch = (p clock / transfer rate) * (H / (L + H)) */
228 	num = CONFIG_SH_I2C_CLOCK * CONFIG_SH_I2C_DATA_HIGH;
229 	tmp = num * 10 / denom;
230 	if (tmp % 10 >= 5)
231 		icch = (u16)((num/denom) + 1);
232 	else
233 		icch = (u16)(num/denom);
234 
235 	debug("clock: %d, speed %d, iccl: %x, icch: %x\n",
236 			CONFIG_SH_I2C_CLOCK, speed, iccl, icch);
237 }
238 
239 static int sh_i2c_read(struct i2c_adapter *adap, uint8_t chip,
240 				uint addr, int alen, u8 *data, int len)
241 {
242 	int ret, i;
243 	struct sh_i2c *dev = (struct sh_i2c *)i2c_dev[adap->hwadapnr];
244 
245 	for (i = 0; i < len; i++) {
246 		ret = sh_i2c_raw_read(dev, chip, addr + i);
247 		if (ret < 0)
248 			return -1;
249 
250 		data[i] = ret & 0xff;
251 		debug("%s: data[%d]: %02x\n", __func__, i, data[i]);
252 	}
253 
254 	return 0;
255 }
256 
257 static int sh_i2c_write(struct i2c_adapter *adap, uint8_t chip, uint addr,
258 				int alen, u8 *data, int len)
259 {
260 	struct sh_i2c *dev = (struct sh_i2c *)i2c_dev[adap->hwadapnr];
261 	int i;
262 
263 	for (i = 0; i < len; i++) {
264 		debug("%s: data[%d]: %02x\n", __func__, i, data[i]);
265 		if (sh_i2c_raw_write(dev, chip, addr + i, data[i]) != 0)
266 			return -1;
267 	}
268 	return 0;
269 }
270 
271 static int
272 sh_i2c_probe(struct i2c_adapter *adap, u8 dev)
273 {
274 	u8 dummy[1];
275 
276 	return sh_i2c_read(adap, dev, 0, 0, dummy, sizeof dummy);
277 }
278 
279 static unsigned int sh_i2c_set_bus_speed(struct i2c_adapter *adap,
280 			unsigned int speed)
281 {
282 	struct sh_i2c *dev = (struct sh_i2c *)i2c_dev[adap->hwadapnr];
283 
284 	sh_i2c_finish(dev);
285 	sh_i2c_init(adap, speed, 0);
286 
287 	return 0;
288 }
289 
290 /*
291  * Register RCAR i2c adapters
292  */
293 U_BOOT_I2C_ADAP_COMPLETE(sh_0, sh_i2c_init, sh_i2c_probe, sh_i2c_read,
294 	sh_i2c_write, sh_i2c_set_bus_speed, CONFIG_SYS_I2C_SH_SPEED0, 0, 0)
295 #ifdef CONFIG_SYS_I2C_SH_BASE1
296 U_BOOT_I2C_ADAP_COMPLETE(sh_1, sh_i2c_init, sh_i2c_probe, sh_i2c_read,
297 	sh_i2c_write, sh_i2c_set_bus_speed, CONFIG_SYS_I2C_SH_SPEED1, 0, 1)
298 #endif
299 #ifdef CONFIG_SYS_I2C_SH_BASE2
300 U_BOOT_I2C_ADAP_COMPLETE(sh_2, sh_i2c_init, sh_i2c_probe, sh_i2c_read,
301 	sh_i2c_write, sh_i2c_set_bus_speed, CONFIG_SYS_I2C_SH_SPEED2, 0, 2)
302 #endif
303 #ifdef CONFIG_SYS_I2C_SH_BASE3
304 U_BOOT_I2C_ADAP_COMPLETE(sh_3, sh_i2c_init, sh_i2c_probe, sh_i2c_read,
305 	sh_i2c_write, sh_i2c_set_bus_speed, CONFIG_SYS_I2C_SH_SPEED3, 0, 3)
306 #endif
307 #ifdef CONFIG_SYS_I2C_SH_BASE4
308 U_BOOT_I2C_ADAP_COMPLETE(sh_4, sh_i2c_init, sh_i2c_probe, sh_i2c_read,
309 	sh_i2c_write, sh_i2c_set_bus_speed, CONFIG_SYS_I2C_SH_SPEED4, 0, 4)
310 #endif
311