diff options
Diffstat (limited to 'drivers/video/bt431.h')
| -rw-r--r-- | drivers/video/bt431.h | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/drivers/video/bt431.h b/drivers/video/bt431.h new file mode 100644 index 000000000000..c826f2787bad --- /dev/null +++ b/drivers/video/bt431.h @@ -0,0 +1,236 @@ +/* + * linux/drivers/video/bt431.h + * + * Copyright 2003 Thiemo Seufer <seufer@csv.ica.uni-stuttgart.de> + * + * This file is subject to the terms and conditions of the GNU General + * Public License. See the file COPYING in the main directory of this + * archive for more details. + */ +#include <linux/types.h> +#include <asm/system.h> + +/* + * Bt431 cursor generator registers, 32-bit aligned. + * Two twin Bt431 are used on the DECstation's PMAG-AA. + */ +struct bt431_regs { + volatile u16 addr_lo; + u16 pad0; + volatile u16 addr_hi; + u16 pad1; + volatile u16 addr_cmap; + u16 pad2; + volatile u16 addr_reg; + u16 pad3; +}; + +static inline u16 bt431_set_value(u8 val) +{ + return ((val << 8) | (val & 0xff)) & 0xffff; +} + +static inline u8 bt431_get_value(u16 val) +{ + return val & 0xff; +} + +/* + * Additional registers addressed indirectly. + */ +#define BT431_REG_CMD 0x0000 +#define BT431_REG_CXLO 0x0001 +#define BT431_REG_CXHI 0x0002 +#define BT431_REG_CYLO 0x0003 +#define BT431_REG_CYHI 0x0004 +#define BT431_REG_WXLO 0x0005 +#define BT431_REG_WXHI 0x0006 +#define BT431_REG_WYLO 0x0007 +#define BT431_REG_WYHI 0x0008 +#define BT431_REG_WWLO 0x0009 +#define BT431_REG_WWHI 0x000a +#define BT431_REG_WHLO 0x000b +#define BT431_REG_WHHI 0x000c + +#define BT431_REG_CRAM_BASE 0x0000 +#define BT431_REG_CRAM_END 0x01ff + +/* + * Command register. + */ +#define BT431_CMD_CURS_ENABLE 0x40 +#define BT431_CMD_XHAIR_ENABLE 0x20 +#define BT431_CMD_OR_CURSORS 0x10 +#define BT431_CMD_AND_CURSORS 0x00 +#define BT431_CMD_1_1_MUX 0x00 +#define BT431_CMD_4_1_MUX 0x04 +#define BT431_CMD_5_1_MUX 0x08 +#define BT431_CMD_xxx_MUX 0x0c +#define BT431_CMD_THICK_1 0x00 +#define BT431_CMD_THICK_3 0x01 +#define BT431_CMD_THICK_5 0x02 +#define BT431_CMD_THICK_7 0x03 + +static inline void bt431_select_reg(struct bt431_regs *regs, int ir) +{ + /* + * The compiler splits the write in two bytes without these + * helper variables. + */ + volatile u16 *lo = &(regs->addr_lo); + volatile u16 *hi = &(regs->addr_hi); + + mb(); + *lo = bt431_set_value(ir & 0xff); + wmb(); + *hi = bt431_set_value((ir >> 8) & 0xff); +} + +/* Autoincrement read/write. */ +static inline u8 bt431_read_reg_inc(struct bt431_regs *regs) +{ + /* + * The compiler splits the write in two bytes without the + * helper variable. + */ + volatile u16 *r = &(regs->addr_reg); + + mb(); + return bt431_get_value(*r); +} + +static inline void bt431_write_reg_inc(struct bt431_regs *regs, u8 value) +{ + /* + * The compiler splits the write in two bytes without the + * helper variable. + */ + volatile u16 *r = &(regs->addr_reg); + + mb(); + *r = bt431_set_value(value); +} + +static inline u8 bt431_read_reg(struct bt431_regs *regs, int ir) +{ + bt431_select_reg(regs, ir); + return bt431_read_reg_inc(regs); +} + +static inline void bt431_write_reg(struct bt431_regs *regs, int ir, u8 value) +{ + bt431_select_reg(regs, ir); + bt431_write_reg_inc(regs, value); +} + +/* Autoincremented read/write for the cursor map. */ +static inline u16 bt431_read_cmap_inc(struct bt431_regs *regs) +{ + /* + * The compiler splits the write in two bytes without the + * helper variable. + */ + volatile u16 *r = &(regs->addr_cmap); + + mb(); + return *r; +} + +static inline void bt431_write_cmap_inc(struct bt431_regs *regs, u16 value) +{ + /* + * The compiler splits the write in two bytes without the + * helper variable. + */ + volatile u16 *r = &(regs->addr_cmap); + + mb(); + *r = value; +} + +static inline u16 bt431_read_cmap(struct bt431_regs *regs, int cr) +{ + bt431_select_reg(regs, cr); + return bt431_read_cmap_inc(regs); +} + +static inline void bt431_write_cmap(struct bt431_regs *regs, int cr, u16 value) +{ + bt431_select_reg(regs, cr); + bt431_write_cmap_inc(regs, value); +} + +static inline void bt431_enable_cursor(struct bt431_regs *regs) +{ + bt431_write_reg(regs, BT431_REG_CMD, + BT431_CMD_CURS_ENABLE | BT431_CMD_OR_CURSORS + | BT431_CMD_4_1_MUX | BT431_CMD_THICK_1); +} + +static inline void bt431_erase_cursor(struct bt431_regs *regs) +{ + bt431_write_reg(regs, BT431_REG_CMD, BT431_CMD_4_1_MUX); +} + +static inline void bt431_position_cursor(struct bt431_regs *regs, u16 x, u16 y) +{ + /* + * Magic from the MACH sources. + * + * Cx = x + D + H - P + * P = 37 if 1:1, 52 if 4:1, 57 if 5:1 + * D = pixel skew between outdata and external data + * H = pixels between HSYNCH falling and active video + * + * Cy = y + V - 32 + * V = scanlines between HSYNCH falling, two or more + * clocks after VSYNCH falling, and active video + */ + x += 412 - 52; + y += 68 - 32; + + /* Use autoincrement. */ + bt431_select_reg(regs, BT431_REG_CXLO); + bt431_write_reg_inc(regs, x & 0xff); /* BT431_REG_CXLO */ + bt431_write_reg_inc(regs, (x >> 8) & 0x0f); /* BT431_REG_CXHI */ + bt431_write_reg_inc(regs, y & 0xff); /* BT431_REG_CYLO */ + bt431_write_reg_inc(regs, (y >> 8) & 0x0f); /* BT431_REG_CYHI */ +} + +static inline void bt431_set_font(struct bt431_regs *regs, u8 fgc, + u16 width, u16 height) +{ + int i; + u16 fgp = fgc ? 0xffff : 0x0000; + u16 bgp = fgc ? 0x0000 : 0xffff; + + bt431_select_reg(regs, BT431_REG_CRAM_BASE); + for (i = BT431_REG_CRAM_BASE; i <= BT431_REG_CRAM_END; i++) { + u16 value; + + if (height << 6 <= i << 3) + value = bgp; + else if (width <= i % 8 << 3) + value = bgp; + else if (((width >> 3) & 0xffff) > i % 8) + value = fgp; + else + value = fgp & ~(bgp << (width % 8 << 1)); + + bt431_write_cmap_inc(regs, value); + } +} + +static inline void bt431_init_cursor(struct bt431_regs *regs) +{ + /* no crosshair window */ + bt431_select_reg(regs, BT431_REG_WXLO); + bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WXLO */ + bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WXHI */ + bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WYLO */ + bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WYHI */ + bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WWLO */ + bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WWHI */ + bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WHLO */ + bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WHHI */ +} |