kernel/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                 pad = (len % 4) ? 4 - (len % 4) : 0;
  97                 for (i = 0; i < pad; i++)
  98                         *buf++ = 0x000;
  99         }
 100
 101         va_start(args, len);
 102         *buf++ = (u8)va_arg(args, unsigned int);
 103         i = len - 1;
 104         while (i--) {
 105                 *buf = (u8)va_arg(args, unsigned int);
 106                 *buf++ |= 0x100; /* dc=1 */
 107         }
 108         va_end(args);
 109         ret = par->fbtftops.write(par, par->buf, (len + pad) * sizeof(u16));
 110         if (ret < 0) {
 111                 dev_err(par->info->device,
 112                         "write() failed and returned %d\n", ret);
 113                 return;
 114         }
 115 }
 116 EXPORT_SYMBOL(fbtft_write_reg8_bus9);
 117
 118 /*****************************************************************************
 119  *
 120  *   int (*write_vmem)(struct fbtft_par *par);
 121  *
 122  *****************************************************************************/
 123
 124 /* 16 bit pixel over 8-bit databus */
 125 int fbtft_write_vmem16_bus8(struct fbtft_par *par, size_t offset, size_t len)
 126 {
 127         u16 *vmem16;
 128         u16 *txbuf16 = (u16 *)par->txbuf.buf;
 129         size_t remain;
 130         size_t to_copy;
 131         size_t tx_array_size;
 132         int i;
 133         int ret = 0;
 134         size_t startbyte_size = 0;
 135
 136         fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s(offset=%zu, len=%zu)\n",
 137                 __func__, offset, len);
 138
 139         remain = len / 2;
 140         vmem16 = (u16 *)(par->info->screen_buffer + offset);
 141
 142         if (par->gpio.dc != -1)
 143                 gpio_set_value(par->gpio.dc, 1);
 144
 145         /* non buffered write */
 146         if (!par->txbuf.buf)
 147                 return par->fbtftops.write(par, vmem16, len);
 148
 149         /* buffered write */
 150         tx_array_size = par->txbuf.len / 2;
 151
 152         if (par->startbyte) {
 153                 txbuf16 = (u16 *)(par->txbuf.buf + 1);
 154                 tx_array_size -= 2;
 155                 *(u8 *)(par->txbuf.buf) = par->startbyte | 0x2;
 156                 startbyte_size = 1;
 157         }
 158
 159         while (remain) {
 160                 to_copy = remain > tx_array_size ? tx_array_size : remain;
 161                 dev_dbg(par->info->device, "    to_copy=%zu, remain=%zu\n",
 162                                                 to_copy, remain - to_copy);
 163
 164                 for (i = 0; i < to_copy; i++)
 165                         txbuf16[i] = cpu_to_be16(vmem16[i]);
 166
 167                 vmem16 = vmem16 + to_copy;
 168                 ret = par->fbtftops.write(par, par->txbuf.buf,
 169                                                 startbyte_size + to_copy * 2);
 170                 if (ret < 0)
 171                         return ret;
 172                 remain -= to_copy;
 173         }
 174
 175         return ret;
 176 }
 177 EXPORT_SYMBOL(fbtft_write_vmem16_bus8);
 178
 179 /* 16 bit pixel over 9-bit SPI bus: dc + high byte, dc + low byte */
 180 int fbtft_write_vmem16_bus9(struct fbtft_par *par, size_t offset, size_t len)
 181 {
 182         u8 *vmem8;
 183         u16 *txbuf16 = par->txbuf.buf;
 184         size_t remain;
 185         size_t to_copy;
 186         size_t tx_array_size;
 187         int i;
 188         int ret = 0;
 189
 190         fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s(offset=%zu, len=%zu)\n",
 191                 __func__, offset, len);
 192
 193         if (!par->txbuf.buf) {
 194                 dev_err(par->info->device, "%s: txbuf.buf is NULL\n", __func__);
 195                 return -1;
 196         }
 197
 198         remain = len;
 199         vmem8 = par->info->screen_buffer + offset;
 200
 201         tx_array_size = par->txbuf.len / 2;
 202
 203         while (remain) {
 204                 to_copy = remain > tx_array_size ? tx_array_size : remain;
 205                 dev_dbg(par->info->device, "    to_copy=%zu, remain=%zu\n",
 206                                                 to_copy, remain - to_copy);
 207
 208 #ifdef __LITTLE_ENDIAN
 209                 for (i = 0; i < to_copy; i += 2) {
 210                         txbuf16[i]     = 0x0100 | vmem8[i + 1];
 211                         txbuf16[i + 1] = 0x0100 | vmem8[i];
 212                 }
 213 #else
 214                 for (i = 0; i < to_copy; i++)
 215                         txbuf16[i]   = 0x0100 | vmem8[i];
 216 #endif
 217                 vmem8 = vmem8 + to_copy;
 218                 ret = par->fbtftops.write(par, par->txbuf.buf, to_copy * 2);
 219                 if (ret < 0)
 220                         return ret;
 221                 remain -= to_copy;
 222         }
 223
 224         return ret;
 225 }
 226 EXPORT_SYMBOL(fbtft_write_vmem16_bus9);
 227
 228 int fbtft_write_vmem8_bus8(struct fbtft_par *par, size_t offset, size_t len)
 229 {
 230         dev_err(par->info->device, "%s: function not implemented\n", __func__);
 231         return -1;
 232 }
 233 EXPORT_SYMBOL(fbtft_write_vmem8_bus8);
 234
 235 /* 16 bit pixel over 16-bit databus */
 236 int fbtft_write_vmem16_bus16(struct fbtft_par *par, size_t offset, size_t len)
 237 {
 238         u16 *vmem16;
 239
 240         fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s(offset=%zu, len=%zu)\n",
 241                 __func__, offset, len);
 242
 243         vmem16 = (u16 *)(par->info->screen_buffer + offset);
 244
 245         if (par->gpio.dc != -1)
 246                 gpio_set_value(par->gpio.dc, 1);
 247
 248         /* no need for buffered write with 16-bit bus */
 249         return par->fbtftops.write(par, vmem16, len);
 250 }
 251 EXPORT_SYMBOL(fbtft_write_vmem16_bus16);