Thomas Petazzoni | c296d5f | 2014-12-31 10:11:09 +0100 | [diff] [blame] | 1 | #include <linux/export.h> |
| 2 | #include <linux/errno.h> |
| 3 | #include <linux/gpio.h> |
| 4 | #include <linux/spi/spi.h> |
Thomas Petazzoni | c296d5f | 2014-12-31 10:11:09 +0100 | [diff] [blame] | 5 | #include "fbtft.h" |
| 6 | |
| 7 | int fbtft_write_spi(struct fbtft_par *par, void *buf, size_t len) |
| 8 | { |
| 9 | struct spi_transfer t = { |
| 10 | .tx_buf = buf, |
| 11 | .len = len, |
| 12 | }; |
| 13 | struct spi_message m; |
| 14 | |
| 15 | fbtft_par_dbg_hex(DEBUG_WRITE, par, par->info->device, u8, buf, len, |
| 16 | "%s(len=%d): ", __func__, len); |
| 17 | |
| 18 | if (!par->spi) { |
| 19 | dev_err(par->info->device, |
| 20 | "%s: par->spi is unexpectedly NULL\n", __func__); |
| 21 | return -1; |
| 22 | } |
| 23 | |
| 24 | spi_message_init(&m); |
| 25 | if (par->txbuf.dma && buf == par->txbuf.buf) { |
| 26 | t.tx_dma = par->txbuf.dma; |
| 27 | m.is_dma_mapped = 1; |
| 28 | } |
| 29 | spi_message_add_tail(&t, &m); |
| 30 | return spi_sync(par->spi, &m); |
| 31 | } |
| 32 | EXPORT_SYMBOL(fbtft_write_spi); |
| 33 | |
| 34 | /** |
| 35 | * fbtft_write_spi_emulate_9() - write SPI emulating 9-bit |
| 36 | * @par: Driver data |
| 37 | * @buf: Buffer to write |
| 38 | * @len: Length of buffer (must be divisible by 8) |
| 39 | * |
| 40 | * When 9-bit SPI is not available, this function can be used to emulate that. |
| 41 | * par->extra must hold a transformation buffer used for transfer. |
| 42 | */ |
| 43 | int fbtft_write_spi_emulate_9(struct fbtft_par *par, void *buf, size_t len) |
| 44 | { |
| 45 | u16 *src = buf; |
| 46 | u8 *dst = par->extra; |
| 47 | size_t size = len / 2; |
| 48 | size_t added = 0; |
| 49 | int bits, i, j; |
| 50 | u64 val, dc, tmp; |
| 51 | |
| 52 | fbtft_par_dbg_hex(DEBUG_WRITE, par, par->info->device, u8, buf, len, |
| 53 | "%s(len=%d): ", __func__, len); |
| 54 | |
| 55 | if (!par->extra) { |
| 56 | dev_err(par->info->device, "%s: error: par->extra is NULL\n", |
| 57 | __func__); |
| 58 | return -EINVAL; |
| 59 | } |
| 60 | if ((len % 8) != 0) { |
| 61 | dev_err(par->info->device, |
Haneen Mohammed | aed1c72 | 2015-03-06 21:59:04 +0300 | [diff] [blame] | 62 | "error: len=%zu must be divisible by 8\n", len); |
Thomas Petazzoni | c296d5f | 2014-12-31 10:11:09 +0100 | [diff] [blame] | 63 | return -EINVAL; |
| 64 | } |
| 65 | |
| 66 | for (i = 0; i < size; i += 8) { |
| 67 | tmp = 0; |
| 68 | bits = 63; |
| 69 | for (j = 0; j < 7; j++) { |
| 70 | dc = (*src & 0x0100) ? 1 : 0; |
| 71 | val = *src & 0x00FF; |
| 72 | tmp |= dc << bits; |
| 73 | bits -= 8; |
| 74 | tmp |= val << bits--; |
| 75 | src++; |
| 76 | } |
| 77 | tmp |= ((*src & 0x0100) ? 1 : 0); |
| 78 | *(u64 *)dst = cpu_to_be64(tmp); |
| 79 | dst += 8; |
| 80 | *dst++ = (u8)(*src++ & 0x00FF); |
| 81 | added++; |
| 82 | } |
| 83 | |
| 84 | return spi_write(par->spi, par->extra, size + added); |
| 85 | } |
| 86 | EXPORT_SYMBOL(fbtft_write_spi_emulate_9); |
| 87 | |
| 88 | int fbtft_read_spi(struct fbtft_par *par, void *buf, size_t len) |
| 89 | { |
| 90 | int ret; |
| 91 | u8 txbuf[32] = { 0, }; |
| 92 | struct spi_transfer t = { |
| 93 | .speed_hz = 2000000, |
| 94 | .rx_buf = buf, |
| 95 | .len = len, |
| 96 | }; |
| 97 | struct spi_message m; |
| 98 | |
| 99 | if (!par->spi) { |
| 100 | dev_err(par->info->device, |
| 101 | "%s: par->spi is unexpectedly NULL\n", __func__); |
| 102 | return -ENODEV; |
| 103 | } |
| 104 | |
| 105 | if (par->startbyte) { |
| 106 | if (len > 32) { |
| 107 | dev_err(par->info->device, |
Haneen Mohammed | aed1c72 | 2015-03-06 21:59:04 +0300 | [diff] [blame] | 108 | "len=%zu can't be larger than 32 when using 'startbyte'\n", |
| 109 | len); |
Thomas Petazzoni | c296d5f | 2014-12-31 10:11:09 +0100 | [diff] [blame] | 110 | return -EINVAL; |
| 111 | } |
| 112 | txbuf[0] = par->startbyte | 0x3; |
| 113 | t.tx_buf = txbuf; |
| 114 | fbtft_par_dbg_hex(DEBUG_READ, par, par->info->device, u8, |
| 115 | txbuf, len, "%s(len=%d) txbuf => ", __func__, len); |
| 116 | } |
| 117 | |
| 118 | spi_message_init(&m); |
| 119 | spi_message_add_tail(&t, &m); |
| 120 | ret = spi_sync(par->spi, &m); |
| 121 | fbtft_par_dbg_hex(DEBUG_READ, par, par->info->device, u8, buf, len, |
| 122 | "%s(len=%d) buf <= ", __func__, len); |
| 123 | |
| 124 | return ret; |
| 125 | } |
| 126 | EXPORT_SYMBOL(fbtft_read_spi); |
| 127 | |
Thomas Petazzoni | c296d5f | 2014-12-31 10:11:09 +0100 | [diff] [blame] | 128 | /* |
| 129 | * Optimized use of gpiolib is twice as fast as no optimization |
| 130 | * only one driver can use the optimized version at a time |
| 131 | */ |
| 132 | int fbtft_write_gpio8_wr(struct fbtft_par *par, void *buf, size_t len) |
| 133 | { |
| 134 | u8 data; |
| 135 | int i; |
| 136 | #ifndef DO_NOT_OPTIMIZE_FBTFT_WRITE_GPIO |
| 137 | static u8 prev_data; |
| 138 | #endif |
| 139 | |
| 140 | fbtft_par_dbg_hex(DEBUG_WRITE, par, par->info->device, u8, buf, len, |
| 141 | "%s(len=%d): ", __func__, len); |
| 142 | |
| 143 | while (len--) { |
| 144 | data = *(u8 *) buf; |
| 145 | |
| 146 | /* Start writing by pulling down /WR */ |
| 147 | gpio_set_value(par->gpio.wr, 0); |
| 148 | |
| 149 | /* Set data */ |
| 150 | #ifndef DO_NOT_OPTIMIZE_FBTFT_WRITE_GPIO |
| 151 | if (data == prev_data) { |
| 152 | gpio_set_value(par->gpio.wr, 0); /* used as delay */ |
| 153 | } else { |
| 154 | for (i = 0; i < 8; i++) { |
| 155 | if ((data & 1) != (prev_data & 1)) |
| 156 | gpio_set_value(par->gpio.db[i], |
Aya Mahfouz | 248d828 | 2015-03-10 19:08:15 +0200 | [diff] [blame] | 157 | data & 1); |
Thomas Petazzoni | c296d5f | 2014-12-31 10:11:09 +0100 | [diff] [blame] | 158 | data >>= 1; |
| 159 | prev_data >>= 1; |
| 160 | } |
| 161 | } |
| 162 | #else |
| 163 | for (i = 0; i < 8; i++) { |
Aya Mahfouz | 248d828 | 2015-03-10 19:08:15 +0200 | [diff] [blame] | 164 | gpio_set_value(par->gpio.db[i], data & 1); |
Thomas Petazzoni | c296d5f | 2014-12-31 10:11:09 +0100 | [diff] [blame] | 165 | data >>= 1; |
| 166 | } |
| 167 | #endif |
| 168 | |
| 169 | /* Pullup /WR */ |
| 170 | gpio_set_value(par->gpio.wr, 1); |
| 171 | |
| 172 | #ifndef DO_NOT_OPTIMIZE_FBTFT_WRITE_GPIO |
| 173 | prev_data = *(u8 *) buf; |
| 174 | #endif |
| 175 | buf++; |
| 176 | } |
| 177 | |
| 178 | return 0; |
| 179 | } |
| 180 | EXPORT_SYMBOL(fbtft_write_gpio8_wr); |
| 181 | |
| 182 | int fbtft_write_gpio16_wr(struct fbtft_par *par, void *buf, size_t len) |
| 183 | { |
| 184 | u16 data; |
| 185 | int i; |
| 186 | #ifndef DO_NOT_OPTIMIZE_FBTFT_WRITE_GPIO |
| 187 | static u16 prev_data; |
| 188 | #endif |
| 189 | |
| 190 | fbtft_par_dbg_hex(DEBUG_WRITE, par, par->info->device, u8, buf, len, |
| 191 | "%s(len=%d): ", __func__, len); |
| 192 | |
| 193 | while (len) { |
| 194 | data = *(u16 *) buf; |
| 195 | |
| 196 | /* Start writing by pulling down /WR */ |
| 197 | gpio_set_value(par->gpio.wr, 0); |
| 198 | |
| 199 | /* Set data */ |
| 200 | #ifndef DO_NOT_OPTIMIZE_FBTFT_WRITE_GPIO |
| 201 | if (data == prev_data) { |
| 202 | gpio_set_value(par->gpio.wr, 0); /* used as delay */ |
| 203 | } else { |
| 204 | for (i = 0; i < 16; i++) { |
| 205 | if ((data & 1) != (prev_data & 1)) |
| 206 | gpio_set_value(par->gpio.db[i], |
Aya Mahfouz | 248d828 | 2015-03-10 19:08:15 +0200 | [diff] [blame] | 207 | data & 1); |
Thomas Petazzoni | c296d5f | 2014-12-31 10:11:09 +0100 | [diff] [blame] | 208 | data >>= 1; |
| 209 | prev_data >>= 1; |
| 210 | } |
| 211 | } |
| 212 | #else |
| 213 | for (i = 0; i < 16; i++) { |
Aya Mahfouz | 248d828 | 2015-03-10 19:08:15 +0200 | [diff] [blame] | 214 | gpio_set_value(par->gpio.db[i], data & 1); |
Thomas Petazzoni | c296d5f | 2014-12-31 10:11:09 +0100 | [diff] [blame] | 215 | data >>= 1; |
| 216 | } |
| 217 | #endif |
| 218 | |
| 219 | /* Pullup /WR */ |
| 220 | gpio_set_value(par->gpio.wr, 1); |
| 221 | |
| 222 | #ifndef DO_NOT_OPTIMIZE_FBTFT_WRITE_GPIO |
| 223 | prev_data = *(u16 *) buf; |
| 224 | #endif |
| 225 | buf += 2; |
| 226 | len -= 2; |
| 227 | } |
| 228 | |
| 229 | return 0; |
| 230 | } |
| 231 | EXPORT_SYMBOL(fbtft_write_gpio16_wr); |
| 232 | |
| 233 | int fbtft_write_gpio16_wr_latched(struct fbtft_par *par, void *buf, size_t len) |
| 234 | { |
| 235 | dev_err(par->info->device, "%s: function not implemented\n", __func__); |
| 236 | return -1; |
| 237 | } |
| 238 | EXPORT_SYMBOL(fbtft_write_gpio16_wr_latched); |