| /* | 
 |  *	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); | 
 | } |