diff options
Diffstat (limited to 'drivers/staging/fbtft/fb_pcd8544.c')
| -rw-r--r-- | drivers/staging/fbtft/fb_pcd8544.c | 118 |
1 files changed, 65 insertions, 53 deletions
diff --git a/drivers/staging/fbtft/fb_pcd8544.c b/drivers/staging/fbtft/fb_pcd8544.c index 8b9ebfb49ef8..15da0ec77513 100644 --- a/drivers/staging/fbtft/fb_pcd8544.c +++ b/drivers/staging/fbtft/fb_pcd8544.c @@ -34,7 +34,7 @@ #define WIDTH 84 #define HEIGHT 48 #define TXBUFLEN (84*6) -#define DEFAULT_GAMMA "40" /* gamma is used to control contrast in this driver */ +#define DEFAULT_GAMMA "40" /* gamma controls the contrast in this driver */ static unsigned tc; module_param(tc, uint, 0); @@ -51,61 +51,73 @@ static int init_display(struct fbtft_par *par) par->fbtftops.reset(par); - /* Function set */ - write_reg(par, 0x21); /* 5:1 1 - 2:0 PD - Powerdown control: chip is active - 1:0 V - Entry mode: horizontal addressing - 0:1 H - Extended instruction set control: extended - */ - - /* H=1 Temperature control */ - write_reg(par, 0x04 | (tc & 0x3)); /* - 2:1 1 - 1:x TC1 - Temperature Coefficient: 0x10 - 0:x TC0 - */ - - /* H=1 Bias system */ - write_reg(par, 0x10 | (bs & 0x7)); /* - 4:1 1 - 3:0 0 - 2:x BS2 - Bias System - 1:x BS1 - 0:x BS0 - */ - - /* Function set */ - write_reg(par, 0x22); /* 5:1 1 - 2:0 PD - Powerdown control: chip is active - 1:1 V - Entry mode: vertical addressing - 0:0 H - Extended instruction set control: basic - */ - - /* H=0 Display control */ - write_reg(par, 0x08 | 4); /* - 3:1 1 - 2:1 D - DE: 10=normal mode - 1:0 0 - 0:0 E - */ + /* Function set + * + * 5:1 1 + * 2:0 PD - Powerdown control: chip is active + * 1:0 V - Entry mode: horizontal addressing + * 0:1 H - Extended instruction set control: extended + */ + write_reg(par, 0x21); + + /* H=1 Temperature control + * + * 2:1 1 + * 1:x TC1 - Temperature Coefficient: 0x10 + * 0:x TC0 + */ + write_reg(par, 0x04 | (tc & 0x3)); + + /* H=1 Bias system + * + * 4:1 1 + * 3:0 0 + * 2:x BS2 - Bias System + * 1:x BS1 + * 0:x BS0 + */ + write_reg(par, 0x10 | (bs & 0x7)); + + /* Function set + * + * 5:1 1 + * 2:0 PD - Powerdown control: chip is active + * 1:1 V - Entry mode: vertical addressing + * 0:0 H - Extended instruction set control: basic + */ + write_reg(par, 0x22); + + /* H=0 Display control + * + * 3:1 1 + * 2:1 D - DE: 10=normal mode + * 1:0 0 + * 0:0 E + */ + write_reg(par, 0x08 | 4); return 0; } static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye) { - fbtft_par_dbg(DEBUG_SET_ADDR_WIN, par, "%s(xs=%d, ys=%d, xe=%d, ye=%d)\n", __func__, xs, ys, xe, ye); - - /* H=0 Set X address of RAM */ - write_reg(par, 0x80); /* 7:1 1 - 6-0: X[6:0] - 0x00 - */ - - /* H=0 Set Y address of RAM */ - write_reg(par, 0x40); /* 7:0 0 - 6:1 1 - 2-0: Y[2:0] - 0x0 - */ + fbtft_par_dbg(DEBUG_SET_ADDR_WIN, par, "%s(xs=%d, ys=%d, xe=%d, ye=%d)\n", + __func__, xs, ys, xe, ye); + + /* H=0 Set X address of RAM + * + * 7:1 1 + * 6-0: X[6:0] - 0x00 + */ + write_reg(par, 0x80); + + /* H=0 Set Y address of RAM + * + * 7:0 0 + * 6:1 1 + * 2-0: Y[2:0] - 0x0 + */ + write_reg(par, 0x40); } static int write_vmem(struct fbtft_par *par, size_t offset, size_t len) @@ -120,9 +132,8 @@ static int write_vmem(struct fbtft_par *par, size_t offset, size_t len) for (x = 0; x < 84; x++) { for (y = 0; y < 6; y++) { *buf = 0x00; - for (i = 0; i < 8; i++) { + for (i = 0; i < 8; i++) *buf |= (vmem16[(y*8+i)*84+x] ? 1 : 0) << i; - } buf++; } } @@ -131,7 +142,8 @@ static int write_vmem(struct fbtft_par *par, size_t offset, size_t len) gpio_set_value(par->gpio.dc, 1); ret = par->fbtftops.write(par, par->txbuf.buf, 6*84); if (ret < 0) - dev_err(par->info->device, "%s: write failed and returned: %d\n", __func__, ret); + dev_err(par->info->device, "write failed and returned: %d\n", + ret); return ret; } |