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Diffstat (limited to '')
| -rw-r--r-- | drivers/video/fbdev/bt455.h | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/drivers/video/fbdev/bt455.h b/drivers/video/fbdev/bt455.h new file mode 100644 index 000000000..dd1404b40 --- /dev/null +++ b/drivers/video/fbdev/bt455.h @@ -0,0 +1,90 @@ +/* + * linux/drivers/video/bt455.h + * + * Copyright 2003 Thiemo Seufer <seufer@csv.ica.uni-stuttgart.de> + * Copyright 2016 Maciej W. Rozycki <macro@linux-mips.org> + * + * 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> + +/* + * Bt455 byte-wide registers, 32-bit aligned. + */ +struct bt455_regs { + volatile u8 addr_cmap; + u8 pad0[3]; + volatile u8 addr_cmap_data; + u8 pad1[3]; + volatile u8 addr_clr; + u8 pad2[3]; + volatile u8 addr_ovly; + u8 pad3[3]; +}; + +static inline void bt455_select_reg(struct bt455_regs *regs, int ir) +{ + mb(); + regs->addr_cmap = ir & 0x0f; +} + +static inline void bt455_reset_reg(struct bt455_regs *regs) +{ + mb(); + regs->addr_clr = 0; +} + +/* + * Read/write to a Bt455 color map register. + */ +static inline void bt455_read_cmap_next(struct bt455_regs *regs, u8 *grey) +{ + mb(); + regs->addr_cmap_data; + rmb(); + *grey = regs->addr_cmap_data & 0xf; + rmb(); + regs->addr_cmap_data; +} + +static inline void bt455_write_cmap_next(struct bt455_regs *regs, u8 grey) +{ + wmb(); + regs->addr_cmap_data = 0x0; + wmb(); + regs->addr_cmap_data = grey & 0xf; + wmb(); + regs->addr_cmap_data = 0x0; +} + +static inline void bt455_write_ovly_next(struct bt455_regs *regs, u8 grey) +{ + wmb(); + regs->addr_ovly = 0x0; + wmb(); + regs->addr_ovly = grey & 0xf; + wmb(); + regs->addr_ovly = 0x0; +} + +static inline void bt455_read_cmap_entry(struct bt455_regs *regs, + int cr, u8 *grey) +{ + bt455_select_reg(regs, cr); + bt455_read_cmap_next(regs, grey); +} + +static inline void bt455_write_cmap_entry(struct bt455_regs *regs, + int cr, u8 grey) +{ + bt455_select_reg(regs, cr); + bt455_write_cmap_next(regs, grey); +} + +static inline void bt455_write_ovly_entry(struct bt455_regs *regs, u8 grey) +{ + bt455_reset_reg(regs); + bt455_write_ovly_next(regs, grey); +} |