diff options
Diffstat (limited to 'firmware/target')
| -rw-r--r-- | firmware/target/sh/archos/player/lcd-as-player.S | 160 |
1 files changed, 103 insertions, 57 deletions
diff --git a/firmware/target/sh/archos/player/lcd-as-player.S b/firmware/target/sh/archos/player/lcd-as-player.S index 7a6324865f..8dc1219e62 100644 --- a/firmware/target/sh/archos/player/lcd-as-player.S +++ b/firmware/target/sh/archos/player/lcd-as-player.S @@ -69,30 +69,76 @@ /* Write a command byte to the lcd controller * * Arguments: - * r4 - data byte (int) + * r4 - command byte (int) * * Register usage: * r0 - scratch - * r1 - data byte (copied) + * r1 - command byte (copied) * r2 - precalculated port value (CS, DS and SC low, SD high) * r3 - lcd port address * r5 - 1 (byte count for reuse of the loop in _lcd_write_data) */ _lcd_write_command: - mov.l .lcdr,r3 /* put lcd data port address in r3 */ - mov r4,r1 /* copy data byte to r1 */ - mov #1,r5 /* set byte count to 1 (!) */ + mov.l .lcdr, r3 /* put lcd data port address in r3 */ + mov r4, r1 /* copy data byte to r1 */ + mov #1, r5 /* set byte count to 1 (!) */ /* This code will fail if an interrupt changes the contents of PBDRL. * If so, we must disable the interrupt here. */ - mov.b @r3,r0 /* r0 = PBDRL */ - or #(LCD_SD),r0 /* r0 |= LCD_SD */ + mov.b @r3, r0 /* r0 = PBDRL */ + or #(LCD_SD), r0 /* r0 |= LCD_SD */ and #(~(LCD_CS|LCD_DS|LCD_SC)),r0 /* r0 &= ~(LCD_CS|LCD_DS|LCD_SC) */ bra .single_transfer /* jump into the transfer loop */ - mov r0,r2 + mov r0, r2 + + + .align 2 + .global _lcd_write_command_e + .type _lcd_write_command_e,@function + +/* Write a command byte and a data byte to the lcd controller + * + * Arguments: + * r4 - command byte + * r5 - data byte + * + * Register usage: + * r0 - scratch + * r1 - command/data byte (copied) + * r2 - precalculated port value (CS, DS and SC low, SD high) + * r3 - lcd port address + * r5 - 1 (byte count for reuse of the loop in _lcd_write_data) + * r6 - data byte (saved) + * r7 - saved pr + */ + +_lcd_write_command_e: + mov.l .lcdr, r3 /* put lcd data port address in r3 */ + mov r4, r1 /* copy data byte to r1 */ + mov r5, r6 + mov #1, r5 /* set byte count to 1 (!) */ + + /* This code will fail if an interrupt changes the contents of PBDRL. + * If so, we must disable the interrupt here. */ + + mov.b @r3, r0 /* r0 = PBDRL */ + or #(LCD_SD), r0 /* r0 |= LCD_SD */ + and #(~(LCD_CS|LCD_DS|LCD_SC)),r0 /* r0 &= ~(LCD_CS|LCD_DS|LCD_SC) */ + + sts pr, r7 + bsr .single_transfer /* jump into the transfer loop */ + mov r0, r2 + + lds r7, pr + mov r6, r1 + mov #1, r5 /* set byte count to 1 (!) */ + or #(LCD_DS|LCD_SD), r0 /* r0 |= LCD_DS|LCD_SD */ + and #(~(LCD_CS|LCD_SC)), r0 /* r0 &= ~(LCD_CS|LCD_SC) */ + bra .single_transfer /* jump into the transfer loop */ + mov r0, r2 .align 2 @@ -116,7 +162,7 @@ _lcd_write_command: */ _lcd_write_data: - mov.l .lcdr,r3 /* put lcd data port address in r3 */ + mov.l .lcdr, r3 /* put lcd data port address in r3 */ nop /* align here */ /* This code will fail if an interrupt changes the contents of PBDRL. @@ -126,98 +172,98 @@ _lcd_write_data: * disable/precalculate/transfer/enable for each iteration. However, * this would significantly decrease performance. */ - mov.b @r3,r0 /* r0 = PBDRL */ - or #(LCD_DS|LCD_SD),r0 /* r0 |= LCD_DS|LCD_SD */ - and #(~(LCD_CS|LCD_SC)),r0 /* r0 &= ~(LCD_CS|LCD_SC) */ - mov r0,r2 + mov.b @r3, r0 /* r0 = PBDRL */ + or #(LCD_DS|LCD_SD), r0 /* r0 |= LCD_DS|LCD_SD */ + and #(~(LCD_CS|LCD_SC)), r0 /* r0 &= ~(LCD_CS|LCD_SC) */ + mov r0, r2 .align 2 .multi_transfer: - mov.b @r4+,r1 /* load data byte from memory */ + mov.b @r4+, r1 /* load data byte from memory */ .single_transfer: shll16 r1 /* shift data to most significant byte */ shll8 r1 shll r1 /* shift the msb into carry */ - mov r2,r0 /* copy precalculated port value */ + mov r2, r0 /* copy precalculated port value */ bt 1f /* data bit = 1? */ - and #(~LCD_SD),r0 /* no: r0 &= ~LCD_SD */ + and #(~LCD_SD), r0 /* no: r0 &= ~LCD_SD */ 1: shll r1 /* next shift here for alignment */ - mov.b r0,@r3 /* set data to port */ - or #(LCD_SC),r0 /* rise SC (independent of SD level) */ - mov.b r0,@r3 /* set to port */ + mov.b r0, @r3 /* set data to port */ + or #(LCD_SC), r0 /* rise SC (independent of SD level) */ + mov.b r0, @r3 /* set to port */ - mov r2,r0 + mov r2, r0 bt 1f - and #(~LCD_SD),r0 + and #(~LCD_SD), r0 1: - mov.b r0,@r3 - or #(LCD_SC),r0 - mov.b r0,@r3 + mov.b r0, @r3 + or #(LCD_SC), r0 + mov.b r0, @r3 shll r1 - mov r2,r0 + mov r2, r0 bt 1f - and #(~LCD_SD),r0 + and #(~LCD_SD), r0 1: shll r1 - mov.b r0,@r3 - or #(LCD_SC),r0 - mov.b r0,@r3 + mov.b r0, @r3 + or #(LCD_SC), r0 + mov.b r0, @r3 - mov r2,r0 + mov r2, r0 bt 1f - and #(~LCD_SD),r0 + and #(~LCD_SD), r0 1: - mov.b r0,@r3 - or #(LCD_SC),r0 - mov.b r0,@r3 + mov.b r0, @r3 + or #(LCD_SC), r0 + mov.b r0, @r3 shll r1 - mov r2,r0 + mov r2, r0 bt 1f - and #(~LCD_SD),r0 + and #(~LCD_SD), r0 1: shll r1 - mov.b r0,@r3 - or #(LCD_SC),r0 - mov.b r0,@r3 + mov.b r0, @r3 + or #(LCD_SC), r0 + mov.b r0, @r3 - mov r2,r0 + mov r2, r0 bt 1f - and #(~LCD_SD),r0 + and #(~LCD_SD), r0 1: - mov.b r0,@r3 - or #(LCD_SC),r0 - mov.b r0,@r3 + mov.b r0, @r3 + or #(LCD_SC), r0 + mov.b r0, @r3 shll r1 - mov r2,r0 + mov r2, r0 bt 1f - and #(~LCD_SD),r0 + and #(~LCD_SD), r0 1: shll r1 - mov.b r0,@r3 - or #(LCD_SC),r0 - mov.b r0,@r3 + mov.b r0, @r3 + or #(LCD_SC), r0 + mov.b r0, @r3 - mov r2,r0 + mov r2, r0 bt 1f - and #(~LCD_SD),r0 + and #(~LCD_SD), r0 1: - mov.b r0,@r3 - or #(LCD_SC),r0 - mov.b r0,@r3 + mov.b r0, @r3 + or #(LCD_SC), r0 + mov.b r0, @r3 - add #-1,r5 /* decrease byte count */ - tst r5,r5 /* r5 == 0 ? */ + add #-1, r5 /* decrease byte count */ + tst r5, r5 /* r5 == 0 ? */ bf .multi_transfer /* no: next iteration */ or #(LCD_CS|LCD_DS|LCD_SD|LCD_SC),r0 /* restore port */ rts - mov.b r0,@r3 + mov.b r0, @r3 /* This is the place to reenable the interrupts, if we have disabled * them. See above. */ |