drivers/staging/fbtft/fbtft-bus.c

   1 #include <linux/export.h>
   2 #include <linux/errno.h>
   3 #include <linux/gpio.h>
   4 #include <linux/spi/spi.h>
   5 #include "fbtft.h"
   6
   7 /*****************************************************************************
   8  *
   9  *   void (*write_reg)(struct fbtft_par *par, int len, ...);
  10  *
  11  *****************************************************************************/
  12
  13 #define define_fbtft_write_reg(func, type, modifier)                          \
  14 void func(struct fbtft_par *par, int len, ...)                                \
  15 {                                                                             \
  16         va_list args;                                                         \
  17         int i, ret;                                                           \
  18         int offset = 0;                                                       \
  19         type *buf = (type *)par->buf;                                         \
  20                                                                               \
  21         if (unlikely(par->debug & DEBUG_WRITE_REGISTER)) {                    \
  22                 va_start(args, len);                                          \
  23                 for (i = 0; i < len; i++) {                                   \
  24                         buf[i] = (type)va_arg(args, unsigned int);            \
  25                 }                                                             \
  26                 va_end(args);                                                 \
  27                 fbtft_par_dbg_hex(DEBUG_WRITE_REGISTER, par, par->info->device, type, buf, len, "%s: ", __func__);   \
  28         }                                                                     \
  29                                                                               \
  30         va_start(args, len);                                                  \
  31                                                                               \
  32         if (par->startbyte) {                                                 \
  33                 *(u8 *)par->buf = par->startbyte;                             \
  34                 buf = (type *)(par->buf + 1);                                 \
  35                 offset = 1;                                                   \
  36         }                                                                     \
  37                                                                               \
  38         *buf = modifier((type)va_arg(args, unsigned int));                    \
  39         if (par->gpio.dc != -1)                                               \
  40                 gpio_set_value(par->gpio.dc, 0);                              \
  41         ret = par->fbtftops.write(par, par->buf, sizeof(type) + offset);      \
  42         if (ret < 0) {                                                        \
  43                 va_end(args);                                                 \
  44                 dev_err(par->info->device, "%s: write() failed and returned %d\n", __func__, ret); \
  45                 return;                                                       \
  46         }                                                                     \
  47         len--;                                                                \
  48                                                                               \
  49         if (par->startbyte)                                                   \
  50                 *(u8 *)par->buf = par->startbyte | 0x2;                       \
  51                                                                               \
  52         if (len) {                                                            \
  53                 i = len;                                                      \
  54                 while (i--) {                                                 \
  55                         *buf++ = modifier((type)va_arg(args, unsigned int));  \
  56                 }                                                             \
  57                 if (par->gpio.dc != -1)                                       \
  58                         gpio_set_value(par->gpio.dc, 1);                      \
  59                 ret = par->fbtftops.write(par, par->buf,                      \
  60                                           len * (sizeof(type) + offset));     \
  61                 if (ret < 0) {                                                \
  62                         va_end(args);                                         \
  63                         dev_err(par->info->device, "%s: write() failed and returned %d\n", __func__, ret); \
  64                         return;                                               \
  65                 }                                                             \
  66         }                                                                     \
  67         va_end(args);                                                         \
  68 }                                                                             \
  69 EXPORT_SYMBOL(func);
  70
  71 define_fbtft_write_reg(fbtft_write_reg8_bus8, u8, )
  72 define_fbtft_write_reg(fbtft_write_reg16_bus8, u16, cpu_to_be16)
  73 define_fbtft_write_reg(fbtft_write_reg16_bus16, u16, )
  74
  75 void fbtft_write_reg8_bus9(struct fbtft_par *par, int len, ...)
  76 {
  77         va_list args;
  78         int i, ret;
  79         int pad = 0;
  80         u16 *buf = (u16 *)par->buf;
  81
  82         if (unlikely(par->debug & DEBUG_WRITE_REGISTER)) {
  83                 va_start(args, len);
  84                 for (i = 0; i < len; i++)
  85                         *(((u8 *)buf) + i) = (u8)va_arg(args, unsigned int);
  86                 va_end(args);
  87                 fbtft_par_dbg_hex(DEBUG_WRITE_REGISTER, par,
  88                         par->info->device, u8, buf, len, "%s: ", __func__);
  89         }
  90         if (len <= 0)
  91                 return;
  92
  93         if (par->spi && (par->spi->bits_per_word == 8)) {
  94                 /* we're emulating 9-bit, pad start of buffer with no-ops
  95                  * (assuming here that zero is a no-op)
  96                  */
  97                 pad = (len % 4) ? 4 - (len % 4) : 0;
  98                 for (i = 0; i < pad; i++)
  99                         *buf++ = 0x000;
 100         }
 101
 102         va_start(args, len);
 103         *buf++ = (u8)va_arg(args, unsigned int);
 104         i = len - 1;
 105         while (i--) {
 106                 *buf = (u8)va_arg(args, unsigned int);
 107                 *buf++ |= 0x100; /* dc=1 */
 108         }
 109         va_end(args);
 110         ret = par->fbtftops.write(par, par->buf, (len + pad) * sizeof(u16));
 111         if (ret < 0) {
 112                 dev_err(par->info->device,
 113                         "write() failed and returned %d\n", ret);
 114                 return;
 115         }
 116 }
 117 EXPORT_SYMBOL(fbtft_write_reg8_bus9);
 118
 119 /*****************************************************************************
 120  *
 121  *   int (*write_vmem)(struct fbtft_par *par);
 122  *
 123  *****************************************************************************/
 124
 125 /* 16 bit pixel over 8-bit databus */
 126 int fbtft_write_vmem16_bus8(struct fbtft_par *par, size_t offset, size_t len)
 127 {
 128         u16 *vmem16;
 129         u16 *txbuf16 = par->txbuf.buf;
 130         size_t remain;
 131         size_t to_copy;
 132         size_t tx_array_size;
 133         int i;
 134         int ret = 0;
 135         size_t startbyte_size = 0;
 136
 137         fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s(offset=%zu, len=%zu)\n",
 138                 __func__, offset, len);
 139
 140         remain = len / 2;
 141         vmem16 = (u16 *)(par->info->screen_buffer + offset);
 142
 143         if (par->gpio.dc != -1)
 144                 gpio_set_value(par->gpio.dc, 1);
 145
 146         /* non buffered write */
 147         if (!par->txbuf.buf)
 148                 return par->fbtftops.write(par, vmem16, len);
 149
 150         /* buffered write */
 151         tx_array_size = par->txbuf.len / 2;
 152
 153         if (par->startbyte) {
 154                 txbuf16 = par->txbuf.buf + 1;
 155                 tx_array_size -= 2;
 156                 *(u8 *)(par->txbuf.buf) = par->startbyte | 0x2;
 157                 startbyte_size = 1;
 158         }
 159
 160         while (remain) {
 161                 to_copy = min(tx_array_size, remain);
 162                 dev_dbg(par->info->device, "    to_copy=%zu, remain=%zu\n",
 163                                                 to_copy, remain - to_copy);
 164
 165                 for (i = 0; i < to_copy; i++)
 166                         txbuf16[i] = cpu_to_be16(vmem16[i]);
 167
 168                 vmem16 = vmem16 + to_copy;
 169                 ret = par->fbtftops.write(par, par->txbuf.buf,
 170                                                 startbyte_size + to_copy * 2);
 171                 if (ret < 0)
 172                         return ret;
 173                 remain -= to_copy;
 174         }
 175
 176         return ret;
 177 }
 178 EXPORT_SYMBOL(fbtft_write_vmem16_bus8);
 179
 180 /* 16 bit pixel over 9-bit SPI bus: dc + high byte, dc + low byte */
 181 int fbtft_write_vmem16_bus9(struct fbtft_par *par, size_t offset, size_t len)
 182 {
 183         u8 *vmem8;
 184         u16 *txbuf16 = par->txbuf.buf;
 185         size_t remain;
 186         size_t to_copy;
 187         size_t tx_array_size;
 188         int i;
 189         int ret = 0;
 190
 191         fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s(offset=%zu, len=%zu)\n",
 192                 __func__, offset, len);
 193
 194         if (!par->txbuf.buf) {
 195                 dev_err(par->info->device, "%s: txbuf.buf is NULL\n", __func__);
 196                 return -1;
 197         }
 198
 199         remain = len;
 200         vmem8 = par->info->screen_buffer + offset;
 201
 202         tx_array_size = par->txbuf.len / 2;
 203
 204         while (remain) {
 205                 to_copy = min(tx_array_size, remain);
 206                 dev_dbg(par->info->device, "    to_copy=%zu, remain=%zu\n",
 207                                                 to_copy, remain - to_copy);
 208
 209 #ifdef __LITTLE_ENDIAN
 210                 for (i = 0; i < to_copy; i += 2) {
 211                         txbuf16[i]     = 0x0100 | vmem8[i + 1];
 212                         txbuf16[i + 1] = 0x0100 | vmem8[i];
 213                 }
 214 #else
 215                 for (i = 0; i < to_copy; i++)
 216                         txbuf16[i]   = 0x0100 | vmem8[i];
 217 #endif
 218                 vmem8 = vmem8 + to_copy;
 219                 ret = par->fbtftops.write(par, par->txbuf.buf, to_copy * 2);
 220                 if (ret < 0)
 221                         return ret;
 222                 remain -= to_copy;
 223         }
 224
 225         return ret;
 226 }
 227 EXPORT_SYMBOL(fbtft_write_vmem16_bus9);
 228
 229 int fbtft_write_vmem8_bus8(struct fbtft_par *par, size_t offset, size_t len)
 230 {
 231         dev_err(par->info->device, "%s: function not implemented\n", __func__);
 232         return -1;
 233 }
 234 EXPORT_SYMBOL(fbtft_write_vmem8_bus8);
 235
 236 /* 16 bit pixel over 16-bit databus */
 237 int fbtft_write_vmem16_bus16(struct fbtft_par *par, size_t offset, size_t len)
 238 {
 239         u16 *vmem16;
 240
 241         fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s(offset=%zu, len=%zu)\n",
 242                 __func__, offset, len);
 243
 244         vmem16 = (u16 *)(par->info->screen_buffer + offset);
 245
 246         if (par->gpio.dc != -1)
 247                 gpio_set_value(par->gpio.dc, 1);
 248
 249         /* no need for buffered write with 16-bit bus */
 250         return par->fbtftops.write(par, vmem16, len);
 251 }
 252 EXPORT_SYMBOL(fbtft_write_vmem16_bus16);