projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| f8a6b1f4 AG |
1 | /* |
| 2 | * Coral-P(A)/Lime I2C adapter driver | |
| 3 | * | |
| 4 | * (C) 2011 DENX Software Engineering, Anatolij Gustschin <agust@denx.de> | |
| 5 | * | |
| 6 | * This program is free software; you can redistribute it and/or modify | |
| 7 | * it under the terms of the GNU General Public License version 2 as | |
| 8 | * published by the Free Software Foundation. | |
| 9 | * | |
| 10 | */ | |
| 11 | ||
| 12 | #include <linux/fb.h> | |
| 13 | #include <linux/i2c.h> | |
| 14 | #include <linux/io.h> | |
| 520fd845 | 15 | #include <linux/delay.h> |
| a8a35931 | 16 | #include <linux/export.h> |
| f8a6b1f4 AG |
17 | |
| 18 | #include "mb862xxfb.h" | |
| 19 | #include "mb862xx_reg.h" | |
| 20 | ||
| 21 | static int mb862xx_i2c_wait_event(struct i2c_adapter *adap) | |
| 22 | { | |
| 23 | struct mb862xxfb_par *par = adap->algo_data; | |
| 24 | u32 reg; | |
| 25 | ||
| 26 | do { | |
| 363d58f5 | 27 | udelay(10); |
| f8a6b1f4 AG |
28 | reg = inreg(i2c, GC_I2C_BCR); |
| 29 | if (reg & (I2C_INT | I2C_BER)) | |
| 30 | break; | |
| 31 | } while (1); | |
| 32 | ||
| 33 | return (reg & I2C_BER) ? 0 : 1; | |
| 34 | } | |
| 35 | ||
| 36 | static int mb862xx_i2c_do_address(struct i2c_adapter *adap, int addr) | |
| 37 | { | |
| 38 | struct mb862xxfb_par *par = adap->algo_data; | |
| 39 | ||
| 40 | outreg(i2c, GC_I2C_DAR, addr); | |
| 41 | outreg(i2c, GC_I2C_CCR, I2C_CLOCK_AND_ENABLE); | |
| 42 | outreg(i2c, GC_I2C_BCR, par->i2c_rs ? I2C_REPEATED_START : I2C_START); | |
| 43 | if (!mb862xx_i2c_wait_event(adap)) | |
| 44 | return -EIO; | |
| 45 | par->i2c_rs = !(inreg(i2c, GC_I2C_BSR) & I2C_LRB); | |
| 46 | return par->i2c_rs; | |
| 47 | } | |
| 48 | ||
| 49 | static int mb862xx_i2c_write_byte(struct i2c_adapter *adap, u8 byte) | |
| 50 | { | |
| 51 | struct mb862xxfb_par *par = adap->algo_data; | |
| 52 | ||
| 53 | outreg(i2c, GC_I2C_DAR, byte); | |
| 54 | outreg(i2c, GC_I2C_BCR, I2C_START); | |
| 55 | if (!mb862xx_i2c_wait_event(adap)) | |
| 56 | return -EIO; | |
| 57 | return !(inreg(i2c, GC_I2C_BSR) & I2C_LRB); | |
| 58 | } | |
| 59 | ||
| 60 | static int mb862xx_i2c_read_byte(struct i2c_adapter *adap, u8 *byte, int last) | |
| 61 | { | |
| 62 | struct mb862xxfb_par *par = adap->algo_data; | |
| 63 | ||
| 64 | outreg(i2c, GC_I2C_BCR, I2C_START | (last ? 0 : I2C_ACK)); | |
| 65 | if (!mb862xx_i2c_wait_event(adap)) | |
| 66 | return 0; | |
| 67 | *byte = inreg(i2c, GC_I2C_DAR); | |
| 68 | return 1; | |
| 69 | } | |
| 70 | ||
| 192e1276 | 71 | static void mb862xx_i2c_stop(struct i2c_adapter *adap) |
| f8a6b1f4 AG |
72 | { |
| 73 | struct mb862xxfb_par *par = adap->algo_data; | |
| 74 | ||
| 75 | outreg(i2c, GC_I2C_BCR, I2C_STOP); | |
| 76 | outreg(i2c, GC_I2C_CCR, I2C_DISABLE); | |
| 77 | par->i2c_rs = 0; | |
| 78 | } | |
| 79 | ||
| 80 | static int mb862xx_i2c_read(struct i2c_adapter *adap, struct i2c_msg *m) | |
| 81 | { | |
| 82 | int i, ret = 0; | |
| 83 | int last = m->len - 1; | |
| 84 | ||
| 85 | for (i = 0; i < m->len; i++) { | |
| 86 | if (!mb862xx_i2c_read_byte(adap, &m->buf[i], i == last)) { | |
| 87 | ret = -EIO; | |
| 88 | break; | |
| 89 | } | |
| 90 | } | |
| 91 | return ret; | |
| 92 | } | |
| 93 | ||
| 94 | static int mb862xx_i2c_write(struct i2c_adapter *adap, struct i2c_msg *m) | |
| 95 | { | |
| 96 | int i, ret = 0; | |
| 97 | ||
| 98 | for (i = 0; i < m->len; i++) { | |
| 99 | if (!mb862xx_i2c_write_byte(adap, m->buf[i])) { | |
| 100 | ret = -EIO; | |
| 101 | break; | |
| 102 | } | |
| 103 | } | |
| 104 | return ret; | |
| 105 | } | |
| 106 | ||
| 107 | static int mb862xx_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, | |
| 108 | int num) | |
| 109 | { | |
| 110 | struct mb862xxfb_par *par = adap->algo_data; | |
| 111 | struct i2c_msg *m; | |
| 112 | int addr; | |
| 113 | int i = 0, err = 0; | |
| 114 | ||
| 115 | dev_dbg(par->dev, "%s: %d msgs\n", __func__, num); | |
| 116 | ||
| 117 | for (i = 0; i < num; i++) { | |
| 118 | m = &msgs[i]; | |
| 119 | if (!m->len) { | |
| 120 | dev_dbg(par->dev, "%s: null msgs\n", __func__); | |
| 121 | continue; | |
| 122 | } | |
| 123 | addr = m->addr; | |
| 124 | if (m->flags & I2C_M_RD) | |
| 125 | addr |= 1; | |
| 126 | ||
| 127 | err = mb862xx_i2c_do_address(adap, addr); | |
| 128 | if (err < 0) | |
| 129 | break; | |
| 130 | if (m->flags & I2C_M_RD) | |
| 131 | err = mb862xx_i2c_read(adap, m); | |
| 132 | else | |
| 133 | err = mb862xx_i2c_write(adap, m); | |
| 134 | } | |
| 135 | ||
| 136 | if (i) | |
| 137 | mb862xx_i2c_stop(adap); | |
| 138 | ||
| 139 | return (err < 0) ? err : i; | |
| 140 | } | |
| 141 | ||
| 142 | static u32 mb862xx_func(struct i2c_adapter *adap) | |
| 143 | { | |
| 144 | return I2C_FUNC_SMBUS_BYTE_DATA; | |
| 145 | } | |
| 146 | ||
| 147 | static const struct i2c_algorithm mb862xx_algo = { | |
| 148 | .master_xfer = mb862xx_xfer, | |
| 149 | .functionality = mb862xx_func, | |
| 150 | }; | |
| 151 | ||
| 152 | static struct i2c_adapter mb862xx_i2c_adapter = { | |
| 153 | .name = "MB862xx I2C adapter", | |
| 154 | .algo = &mb862xx_algo, | |
| 155 | .owner = THIS_MODULE, | |
| 156 | }; | |
| 157 | ||
| 158 | int mb862xx_i2c_init(struct mb862xxfb_par *par) | |
| 159 | { | |
| 160 | int ret; | |
| 161 | ||
| 162 | mb862xx_i2c_adapter.algo_data = par; | |
| 163 | par->adap = &mb862xx_i2c_adapter; | |
| 164 | ||
| 165 | ret = i2c_add_adapter(par->adap); | |
| 166 | if (ret < 0) { | |
| 167 | dev_err(par->dev, "failed to add %s\n", | |
| 168 | mb862xx_i2c_adapter.name); | |
| 169 | } | |
| 170 | return ret; | |
| 171 | } | |
| 172 | ||
| 173 | void mb862xx_i2c_exit(struct mb862xxfb_par *par) | |
| 174 | { | |
| 175 | if (par->adap) { | |
| 176 | i2c_del_adapter(par->adap); | |
| 177 | par->adap = NULL; | |
| 178 | } | |
| 179 | } |