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         ret = fbtft_write_buf_dc(par, par->buf, sizeof(type) + offset, 0);    \
  40         if (ret < 0)                                                          \
  41                 goto out;                                                     \
  42         len--;                                                                \
  43                                                                               \
  44         if (par->startbyte)                                                   \
  45                 *(u8 *)par->buf = par->startbyte | 0x2;                       \
  46                                                                               \
  47         if (len) {                                                            \
  48                 i = len;                                                      \
  49                 while (i--)                                                   \
  50                         *buf++ = modifier((type)va_arg(args, unsigned int));  \
  51                 fbtft_write_buf_dc(par, par->buf,                             \
  52                                    len * (sizeof(type) + offset), 1);         \
  53         }                                                                     \
  54 out:                                                                          \
  55         va_end(args);                                                         \
  56 }                                                                             \
  57 EXPORT_SYMBOL(func);
  58
  59 define_fbtft_write_reg(fbtft_write_reg8_bus8, u8, )
  60 define_fbtft_write_reg(fbtft_write_reg16_bus8, u16, cpu_to_be16)
  61 define_fbtft_write_reg(fbtft_write_reg16_bus16, u16, )
  62
  63 void fbtft_write_reg8_bus9(struct fbtft_par *par, int len, ...)
  64 {
  65         va_list args;
  66         int i, ret;
  67         int pad = 0;
  68         u16 *buf = (u16 *)par->buf;
  69
  70         if (unlikely(par->debug & DEBUG_WRITE_REGISTER)) {
  71                 va_start(args, len);
  72                 for (i = 0; i < len; i++)
  73                         *(((u8 *)buf) + i) = (u8)va_arg(args, unsigned int);
  74                 va_end(args);
  75                 fbtft_par_dbg_hex(DEBUG_WRITE_REGISTER, par,
  76                         par->info->device, u8, buf, len, "%s: ", __func__);
  77         }
  78         if (len <= 0)
  79                 return;
  80
  81         if (par->spi && (par->spi->bits_per_word == 8)) {
  82                 /* we're emulating 9-bit, pad start of buffer with no-ops
  83                  * (assuming here that zero is a no-op)
  84                  */
  85                 pad = (len % 4) ? 4 - (len % 4) : 0;
  86                 for (i = 0; i < pad; i++)
  87                         *buf++ = 0x000;
  88         }
  89
  90         va_start(args, len);
  91         *buf++ = (u8)va_arg(args, unsigned int);
  92         i = len - 1;
  93         while (i--) {
  94                 *buf = (u8)va_arg(args, unsigned int);
  95                 *buf++ |= 0x100; /* dc=1 */
  96         }
  97         va_end(args);
  98         ret = par->fbtftops.write(par, par->buf, (len + pad) * sizeof(u16));
  99         if (ret < 0) {
 100                 dev_err(par->info->device,
 101                         "write() failed and returned %d\n", ret);
 102                 return;
 103         }
 104 }
 105 EXPORT_SYMBOL(fbtft_write_reg8_bus9);
 106
 107 /*****************************************************************************
 108  *
 109  *   int (*write_vmem)(struct fbtft_par *par);
 110  *
 111  *****************************************************************************/
 112
 113 /* 16 bit pixel over 8-bit databus */
 114 int fbtft_write_vmem16_bus8(struct fbtft_par *par, size_t offset, size_t len)
 115 {
 116         u16 *vmem16;
 117         __be16 *txbuf16 = par->txbuf.buf;
 118         size_t remain;
 119         size_t to_copy;
 120         size_t tx_array_size;
 121         int i;
 122         int ret = 0;
 123         size_t startbyte_size = 0;
 124
 125         fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s(offset=%zu, len=%zu)\n",
 126                 __func__, offset, len);
 127
 128         remain = len / 2;
 129         vmem16 = (u16 *)(par->info->screen_buffer + offset);
 130
 131         if (par->gpio.dc != -1)
 132                 gpio_set_value(par->gpio.dc, 1);
 133
 134         /* non buffered write */
 135         if (!par->txbuf.buf)
 136                 return par->fbtftops.write(par, vmem16, len);
 137
 138         /* buffered write */
 139         tx_array_size = par->txbuf.len / 2;
 140
 141         if (par->startbyte) {
 142                 txbuf16 = par->txbuf.buf + 1;
 143                 tx_array_size -= 2;
 144                 *(u8 *)(par->txbuf.buf) = par->startbyte | 0x2;
 145                 startbyte_size = 1;
 146         }
 147
 148         while (remain) {
 149                 to_copy = min(tx_array_size, remain);
 150                 dev_dbg(par->info->device, "    to_copy=%zu, remain=%zu\n",
 151                                                 to_copy, remain - to_copy);
 152
 153                 for (i = 0; i < to_copy; i++)
 154                         txbuf16[i] = cpu_to_be16(vmem16[i]);
 155
 156                 vmem16 = vmem16 + to_copy;
 157                 ret = par->fbtftops.write(par, par->txbuf.buf,
 158                                                 startbyte_size + to_copy * 2);
 159                 if (ret < 0)
 160                         return ret;
 161                 remain -= to_copy;
 162         }
 163
 164         return ret;
 165 }
 166 EXPORT_SYMBOL(fbtft_write_vmem16_bus8);
 167
 168 /* 16 bit pixel over 9-bit SPI bus: dc + high byte, dc + low byte */
 169 int fbtft_write_vmem16_bus9(struct fbtft_par *par, size_t offset, size_t len)
 170 {
 171         u8 *vmem8;
 172         u16 *txbuf16 = par->txbuf.buf;
 173         size_t remain;
 174         size_t to_copy;
 175         size_t tx_array_size;
 176         int i;
 177         int ret = 0;
 178
 179         fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s(offset=%zu, len=%zu)\n",
 180                 __func__, offset, len);
 181
 182         if (!par->txbuf.buf) {
 183                 dev_err(par->info->device, "%s: txbuf.buf is NULL\n", __func__);
 184                 return -1;
 185         }
 186
 187         remain = len;
 188         vmem8 = par->info->screen_buffer + offset;
 189
 190         tx_array_size = par->txbuf.len / 2;
 191
 192         while (remain) {
 193                 to_copy = min(tx_array_size, remain);
 194                 dev_dbg(par->info->device, "    to_copy=%zu, remain=%zu\n",
 195                                                 to_copy, remain - to_copy);
 196
 197 #ifdef __LITTLE_ENDIAN
 198                 for (i = 0; i < to_copy; i += 2) {
 199                         txbuf16[i]     = 0x0100 | vmem8[i + 1];
 200                         txbuf16[i + 1] = 0x0100 | vmem8[i];
 201                 }
 202 #else
 203                 for (i = 0; i < to_copy; i++)
 204                         txbuf16[i]   = 0x0100 | vmem8[i];
 205 #endif
 206                 vmem8 = vmem8 + to_copy;
 207                 ret = par->fbtftops.write(par, par->txbuf.buf, to_copy * 2);
 208                 if (ret < 0)
 209                         return ret;
 210                 remain -= to_copy;
 211         }
 212
 213         return ret;
 214 }
 215 EXPORT_SYMBOL(fbtft_write_vmem16_bus9);
 216
 217 int fbtft_write_vmem8_bus8(struct fbtft_par *par, size_t offset, size_t len)
 218 {
 219         dev_err(par->info->device, "%s: function not implemented\n", __func__);
 220         return -1;
 221 }
 222 EXPORT_SYMBOL(fbtft_write_vmem8_bus8);
 223
 224 /* 16 bit pixel over 16-bit databus */
 225 int fbtft_write_vmem16_bus16(struct fbtft_par *par, size_t offset, size_t len)
 226 {
 227         u16 *vmem16;
 228
 229         fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s(offset=%zu, len=%zu)\n",
 230                 __func__, offset, len);
 231
 232         vmem16 = (u16 *)(par->info->screen_buffer + offset);
 233
 234         /* no need for buffered write with 16-bit bus */
 235         return fbtft_write_buf_dc(par, vmem16, len, 1);
 236 }
 237 EXPORT_SYMBOL(fbtft_write_vmem16_bus16);