1 /* 2 * linux/drivers/video/bt455.h 3 * 4 * Copyright 2003 Thiemo Seufer <seufer@csv.ica.uni-stuttgart.de> 5 * Copyright 2016 Maciej W. Rozycki <macro@linux-mips.org> 6 * 7 * This file is subject to the terms and conditions of the GNU General 8 * Public License. See the file COPYING in the main directory of this 9 * archive for more details. 10 */ 11 #include <linux/types.h> 12 13 /* 14 * Bt455 byte-wide registers, 32-bit aligned. 15 */ 16 struct bt455_regs { 17 volatile u8 addr_cmap; 18 u8 pad0[3]; 19 volatile u8 addr_cmap_data; 20 u8 pad1[3]; 21 volatile u8 addr_clr; 22 u8 pad2[3]; 23 volatile u8 addr_ovly; 24 u8 pad3[3]; 25 }; 26 27 static inline void bt455_select_reg(struct bt455_regs *regs, int ir) 28 { 29 mb(); 30 regs->addr_cmap = ir & 0x0f; 31 } 32 33 static inline void bt455_reset_reg(struct bt455_regs *regs) 34 { 35 mb(); 36 regs->addr_clr = 0; 37 } 38 39 /* 40 * Read/write to a Bt455 color map register. 41 */ 42 static inline void bt455_read_cmap_next(struct bt455_regs *regs, u8 *grey) 43 { 44 mb(); 45 regs->addr_cmap_data; 46 rmb(); 47 *grey = regs->addr_cmap_data & 0xf; 48 rmb(); 49 regs->addr_cmap_data; 50 } 51 52 static inline void bt455_write_cmap_next(struct bt455_regs *regs, u8 grey) 53 { 54 wmb(); 55 regs->addr_cmap_data = 0x0; 56 wmb(); 57 regs->addr_cmap_data = grey & 0xf; 58 wmb(); 59 regs->addr_cmap_data = 0x0; 60 } 61 62 static inline void bt455_write_ovly_next(struct bt455_regs *regs, u8 grey) 63 { 64 wmb(); 65 regs->addr_ovly = 0x0; 66 wmb(); 67 regs->addr_ovly = grey & 0xf; 68 wmb(); 69 regs->addr_ovly = 0x0; 70 } 71 72 static inline void bt455_read_cmap_entry(struct bt455_regs *regs, 73 int cr, u8 *grey) 74 { 75 bt455_select_reg(regs, cr); 76 bt455_read_cmap_next(regs, grey); 77 } 78 79 static inline void bt455_write_cmap_entry(struct bt455_regs *regs, 80 int cr, u8 grey) 81 { 82 bt455_select_reg(regs, cr); 83 bt455_write_cmap_next(regs, grey); 84 } 85 86 static inline void bt455_write_ovly_entry(struct bt455_regs *regs, u8 grey) 87 { 88 bt455_reset_reg(regs); 89 bt455_write_ovly_next(regs, grey); 90 } 91