diff options
Diffstat (limited to 'openpicc/os/boot/boot.s')
| -rw-r--r-- | openpicc/os/boot/boot.s | 43 |
1 files changed, 33 insertions, 10 deletions
diff --git a/openpicc/os/boot/boot.s b/openpicc/os/boot/boot.s index 95bc130..0000479 100644 --- a/openpicc/os/boot/boot.s +++ b/openpicc/os/boot/boot.s @@ -5,6 +5,8 @@ .extern AT91F_LowLevelInit .extern pio_irq_isr_value .extern ssc_tx_pending + .extern ssc_tx_fiq_fdt_cdiv + .extern ssc_tx_fiq_fdt_ssc .text .code 32 @@ -60,6 +62,7 @@ .equ PIOA_IDR, 0x44 .equ PIOA_ISR, 0x4c .equ TC_CCR, 0x00 +.equ TC2_CV, (0x80+0x10) .equ AIC_EOICR, (304) .equ PIO_LED1, (1 << 25) .equ PIO_LED2, (1 << 12) @@ -68,11 +71,6 @@ .equ PIO_SECONDARY_IRQ, 31 .equ PIO_SECONDARY_IRQ_BIT, (1 << PIO_SECONDARY_IRQ) -/* FIQ latency is approx 1us. At 13.56 MHz carrier frequency this means that - * 13.56 cycles of the carrier have passed when the FIQ kicks in and this is - * the amount that CV0 should be loaded to. (Round up) */ -.equ TC0_FRAME_OFFSET, 9 - start: _start: _mainCRTStartup: @@ -241,13 +239,38 @@ my_fiq_handler: ldrne r11, =ssc_tx_pending ldrne r8, [r11] tstne r8, #0x01 /* Check whether a TX is pending */ + beq .no_ssc + + mov r8, #PIO_LED1 + str r8, [r10, #PIOA_SODR] /* disable LED */ + + mov r8, #0x00 + str r8, [r11] /* Set ssc_tx_pending to 0 */ - movne r8, #0x00 - strne r8, [r11] /* Set ssc_tx_pending to 0 */ + ldr r11, =ssc_tx_fiq_fdt_cdiv + ldr r11, [r11] /* r11 == ssc_tx_fiq_fdt_cdiv */ + +.wait_for_fdt_cdiv: + ldr r8, [r12, #TC2_CV] + cmp r8, r11 + bmi .wait_for_fdt_cdiv /* spin while TC2.CV is less fdt_cdiv */ + + str r9, [r12, #TC_CCR] /* SWTRG on TC0 */ + + ldr r11, =ssc_tx_fiq_fdt_ssc + ldr r11, [r11] /* r11 == ssc_tx_fiq_fdt_ssc */ + +.wait_for_fdt_ssc: + ldr r8, [r12, #TC2_CV] + cmp r8, r11 + bmi .wait_for_fdt_ssc /* spin while TC2.CV is less fdt_ssc */ + + mov r11, #PIO_LED1 + str r11, [r10, #PIOA_CODR] /* enable LED */ - ldrne r11, =AT91C_BASE_SSC - movne r8, #SSC_CR_TXEN - strne r8, [r11, #SSC_CR] /* Write TXEN to SSC_CR, enables tx */ + ldr r11, =AT91C_BASE_SSC + mov r8, #SSC_CR_TXEN + str r8, [r11, #SSC_CR] /* Write TXEN to SSC_CR, enables tx */ .no_ssc: /* Trigger PIO_SECONDARY_IRQ */ |