xref: /openbmc/u-boot/drivers/i2c/ihs_i2c.c (revision e30d2bd4)
1 /*
2  * (C) Copyright 2013
3  * Dirk Eibach,  Guntermann & Drunck GmbH, eibach@gdsys.de
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  *
7  * NOTE: This driver should be converted to driver model before June 2017.
8  * Please see doc/driver-model/i2c-howto.txt for instructions.
9  */
10 
11 #include <common.h>
12 #include <i2c.h>
13 #include <gdsys_fpga.h>
14 
15 DECLARE_GLOBAL_DATA_PTR;
16 
17 #ifdef CONFIG_SYS_I2C_IHS_DUAL
18 #define I2C_SET_REG(fld, val) \
19 	do { \
20 		if (I2C_ADAP_HWNR & 0x10) \
21 			FPGA_SET_REG(I2C_ADAP_HWNR & 0xf, i2c1.fld, val); \
22 		else \
23 			FPGA_SET_REG(I2C_ADAP_HWNR, i2c0.fld, val); \
24 	} while (0)
25 #else
26 #define I2C_SET_REG(fld, val) \
27 		FPGA_SET_REG(I2C_ADAP_HWNR, i2c0.fld, val)
28 #endif
29 
30 #ifdef CONFIG_SYS_I2C_IHS_DUAL
31 #define I2C_GET_REG(fld, val) \
32 	do {					\
33 		if (I2C_ADAP_HWNR & 0x10) \
34 			FPGA_GET_REG(I2C_ADAP_HWNR & 0xf, i2c1.fld, val); \
35 		else \
36 			FPGA_GET_REG(I2C_ADAP_HWNR, i2c0.fld, val); \
37 	} while (0)
38 #else
39 #define I2C_GET_REG(fld, val) \
40 		FPGA_GET_REG(I2C_ADAP_HWNR, i2c0.fld, val)
41 #endif
42 
43 enum {
44 	I2CINT_ERROR_EV = 1 << 13,
45 	I2CINT_TRANSMIT_EV = 1 << 14,
46 	I2CINT_RECEIVE_EV = 1 << 15,
47 };
48 
49 enum {
50 	I2CMB_WRITE = 1 << 10,
51 	I2CMB_2BYTE = 1 << 11,
52 	I2CMB_HOLD_BUS = 1 << 13,
53 	I2CMB_NATIVE = 2 << 14,
54 };
55 
56 static int wait_for_int(bool read)
57 {
58 	u16 val;
59 	unsigned int ctr = 0;
60 
61 	I2C_GET_REG(interrupt_status, &val);
62 	while (!(val & (I2CINT_ERROR_EV
63 	       | (read ? I2CINT_RECEIVE_EV : I2CINT_TRANSMIT_EV)))) {
64 		udelay(10);
65 		if (ctr++ > 5000) {
66 			return 1;
67 		}
68 		I2C_GET_REG(interrupt_status, &val);
69 	}
70 
71 	return (val & I2CINT_ERROR_EV) ? 1 : 0;
72 }
73 
74 static int ihs_i2c_transfer(uchar chip, uchar *buffer, int len, bool read,
75 			    bool is_last)
76 {
77 	u16 val;
78 
79 	I2C_SET_REG(interrupt_status, I2CINT_ERROR_EV
80 		     | I2CINT_RECEIVE_EV | I2CINT_TRANSMIT_EV);
81 	I2C_GET_REG(interrupt_status, &val);
82 
83 	if (!read && len) {
84 		val = buffer[0];
85 
86 		if (len > 1)
87 			val |= buffer[1] << 8;
88 		I2C_SET_REG(write_mailbox_ext, val);
89 	}
90 
91 	I2C_SET_REG(write_mailbox,
92 		    I2CMB_NATIVE
93 		    | (read ? 0 : I2CMB_WRITE)
94 		    | (chip << 1)
95 		    | ((len > 1) ? I2CMB_2BYTE : 0)
96 		    | (is_last ? 0 : I2CMB_HOLD_BUS));
97 
98 	if (wait_for_int(read))
99 		return 1;
100 
101 	if (read) {
102 		I2C_GET_REG(read_mailbox_ext, &val);
103 		buffer[0] = val & 0xff;
104 		if (len > 1)
105 			buffer[1] = val >> 8;
106 	}
107 
108 	return 0;
109 }
110 
111 static int ihs_i2c_address(uchar chip, uint addr, int alen, bool hold_bus)
112 {
113 	int shift = (alen-1) * 8;
114 
115 	while (alen) {
116 		int transfer = min(alen, 2);
117 		uchar buf[2];
118 		bool is_last = alen <= transfer;
119 
120 		buf[0] = addr >> shift;
121 		if (alen > 1)
122 			buf[1] = addr >> (shift - 8);
123 
124 		if (ihs_i2c_transfer(chip, buf, transfer, false,
125 				     hold_bus ? false : is_last))
126 			return 1;
127 
128 		shift -= 16;
129 		alen -= transfer;
130 	}
131 
132 	return 0;
133 }
134 
135 static int ihs_i2c_access(struct i2c_adapter *adap, uchar chip, uint addr,
136 			  int alen, uchar *buffer, int len, bool read)
137 {
138 	if (len <= 0)
139 		return 1;
140 
141 	if (ihs_i2c_address(chip, addr, alen, len))
142 		return 1;
143 
144 	while (len) {
145 		int transfer = min(len, 2);
146 
147 		if (ihs_i2c_transfer(chip, buffer, transfer, read,
148 				     len <= transfer))
149 			return 1;
150 
151 		buffer += transfer;
152 		addr += transfer;
153 		len -= transfer;
154 	}
155 
156 	return 0;
157 }
158 
159 
160 static void ihs_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
161 {
162 #ifdef CONFIG_SYS_I2C_INIT_BOARD
163 	/*
164 	 * Call board specific i2c bus reset routine before accessing the
165 	 * environment, which might be in a chip on that bus. For details
166 	 * about this problem see doc/I2C_Edge_Conditions.
167 	 */
168 	i2c_init_board();
169 #endif
170 }
171 
172 static int ihs_i2c_probe(struct i2c_adapter *adap, uchar chip)
173 {
174 	uchar buffer[2];
175 
176 	if (ihs_i2c_transfer(chip, buffer, 0, true, true))
177 		return 1;
178 
179 	return 0;
180 }
181 
182 static int ihs_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
183 			int alen, uchar *buffer, int len)
184 {
185 	return ihs_i2c_access(adap, chip, addr, alen, buffer, len, true);
186 }
187 
188 static int ihs_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
189 			 int alen, uchar *buffer, int len)
190 {
191 	return ihs_i2c_access(adap, chip, addr, alen, buffer, len, false);
192 }
193 
194 static unsigned int ihs_i2c_set_bus_speed(struct i2c_adapter *adap,
195 					  unsigned int speed)
196 {
197 	if (speed != adap->speed)
198 		return 1;
199 	return speed;
200 }
201 
202 /*
203  * Register IHS i2c adapters
204  */
205 #ifdef CONFIG_SYS_I2C_IHS_CH0
206 U_BOOT_I2C_ADAP_COMPLETE(ihs0, ihs_i2c_init, ihs_i2c_probe,
207 			 ihs_i2c_read, ihs_i2c_write,
208 			 ihs_i2c_set_bus_speed,
209 			 CONFIG_SYS_I2C_IHS_SPEED_0,
210 			 CONFIG_SYS_I2C_IHS_SLAVE_0, 0)
211 #ifdef CONFIG_SYS_I2C_IHS_DUAL
212 U_BOOT_I2C_ADAP_COMPLETE(ihs0_1, ihs_i2c_init, ihs_i2c_probe,
213 			 ihs_i2c_read, ihs_i2c_write,
214 			 ihs_i2c_set_bus_speed,
215 			 CONFIG_SYS_I2C_IHS_SPEED_0_1,
216 			 CONFIG_SYS_I2C_IHS_SLAVE_0_1, 16)
217 #endif
218 #endif
219 #ifdef CONFIG_SYS_I2C_IHS_CH1
220 U_BOOT_I2C_ADAP_COMPLETE(ihs1, ihs_i2c_init, ihs_i2c_probe,
221 			 ihs_i2c_read, ihs_i2c_write,
222 			 ihs_i2c_set_bus_speed,
223 			 CONFIG_SYS_I2C_IHS_SPEED_1,
224 			 CONFIG_SYS_I2C_IHS_SLAVE_1, 1)
225 #ifdef CONFIG_SYS_I2C_IHS_DUAL
226 U_BOOT_I2C_ADAP_COMPLETE(ihs1_1, ihs_i2c_init, ihs_i2c_probe,
227 			 ihs_i2c_read, ihs_i2c_write,
228 			 ihs_i2c_set_bus_speed,
229 			 CONFIG_SYS_I2C_IHS_SPEED_1_1,
230 			 CONFIG_SYS_I2C_IHS_SLAVE_1_1, 17)
231 #endif
232 #endif
233 #ifdef CONFIG_SYS_I2C_IHS_CH2
234 U_BOOT_I2C_ADAP_COMPLETE(ihs2, ihs_i2c_init, ihs_i2c_probe,
235 			 ihs_i2c_read, ihs_i2c_write,
236 			 ihs_i2c_set_bus_speed,
237 			 CONFIG_SYS_I2C_IHS_SPEED_2,
238 			 CONFIG_SYS_I2C_IHS_SLAVE_2, 2)
239 #ifdef CONFIG_SYS_I2C_IHS_DUAL
240 U_BOOT_I2C_ADAP_COMPLETE(ihs2_1, ihs_i2c_init, ihs_i2c_probe,
241 			 ihs_i2c_read, ihs_i2c_write,
242 			 ihs_i2c_set_bus_speed,
243 			 CONFIG_SYS_I2C_IHS_SPEED_2_1,
244 			 CONFIG_SYS_I2C_IHS_SLAVE_2_1, 18)
245 #endif
246 #endif
247 #ifdef CONFIG_SYS_I2C_IHS_CH3
248 U_BOOT_I2C_ADAP_COMPLETE(ihs3, ihs_i2c_init, ihs_i2c_probe,
249 			 ihs_i2c_read, ihs_i2c_write,
250 			 ihs_i2c_set_bus_speed,
251 			 CONFIG_SYS_I2C_IHS_SPEED_3,
252 			 CONFIG_SYS_I2C_IHS_SLAVE_3, 3)
253 #ifdef CONFIG_SYS_I2C_IHS_DUAL
254 U_BOOT_I2C_ADAP_COMPLETE(ihs3_1, ihs_i2c_init, ihs_i2c_probe,
255 			 ihs_i2c_read, ihs_i2c_write,
256 			 ihs_i2c_set_bus_speed,
257 			 CONFIG_SYS_I2C_IHS_SPEED_3_1,
258 			 CONFIG_SYS_I2C_IHS_SLAVE_3_1, 19)
259 #endif
260 #endif
261