162306a36Sopenharmony_ci/* SPDX-License-Identifier: GPL-2.0-only */ 262306a36Sopenharmony_ci/* 362306a36Sopenharmony_ci * Copyright (C) 2009 Sascha Hauer <s.hauer@pengutronix.de> 462306a36Sopenharmony_ci */ 562306a36Sopenharmony_ci 662306a36Sopenharmony_ci#include <linux/linkage.h> 762306a36Sopenharmony_ci#include <asm/assembler.h> 862306a36Sopenharmony_ci 962306a36Sopenharmony_ci/* 1062306a36Sopenharmony_ci * r8 = bit 0-15: tx offset, bit 16-31: tx buffer size 1162306a36Sopenharmony_ci * r9 = bit 0-15: rx offset, bit 16-31: rx buffer size 1262306a36Sopenharmony_ci */ 1362306a36Sopenharmony_ci 1462306a36Sopenharmony_ci#define SSI_STX0 0x00 1562306a36Sopenharmony_ci#define SSI_SRX0 0x08 1662306a36Sopenharmony_ci#define SSI_SISR 0x14 1762306a36Sopenharmony_ci#define SSI_SIER 0x18 1862306a36Sopenharmony_ci#define SSI_SACNT 0x38 1962306a36Sopenharmony_ci 2062306a36Sopenharmony_ci#define SSI_SACNT_AC97EN (1 << 0) 2162306a36Sopenharmony_ci 2262306a36Sopenharmony_ci#define SSI_SIER_TFE0_EN (1 << 0) 2362306a36Sopenharmony_ci#define SSI_SISR_TFE0 (1 << 0) 2462306a36Sopenharmony_ci#define SSI_SISR_RFF0 (1 << 2) 2562306a36Sopenharmony_ci#define SSI_SIER_RFF0_EN (1 << 2) 2662306a36Sopenharmony_ci 2762306a36Sopenharmony_ci .text 2862306a36Sopenharmony_ci .global imx_ssi_fiq_start 2962306a36Sopenharmony_ci .global imx_ssi_fiq_end 3062306a36Sopenharmony_ci .global imx_ssi_fiq_base 3162306a36Sopenharmony_ci .global imx_ssi_fiq_rx_buffer 3262306a36Sopenharmony_ci .global imx_ssi_fiq_tx_buffer 3362306a36Sopenharmony_ci 3462306a36Sopenharmony_ci/* 3562306a36Sopenharmony_ci * imx_ssi_fiq_start is _intentionally_ not marked as a function symbol 3662306a36Sopenharmony_ci * using ENDPROC(). imx_ssi_fiq_start and imx_ssi_fiq_end are used to 3762306a36Sopenharmony_ci * mark the function body so that it can be copied to the FIQ vector in 3862306a36Sopenharmony_ci * the vectors page. imx_ssi_fiq_start should only be called as the result 3962306a36Sopenharmony_ci * of an FIQ: calling it directly will not work. 4062306a36Sopenharmony_ci */ 4162306a36Sopenharmony_ciimx_ssi_fiq_start: 4262306a36Sopenharmony_ci ldr r12, .L_imx_ssi_fiq_base 4362306a36Sopenharmony_ci 4462306a36Sopenharmony_ci /* TX */ 4562306a36Sopenharmony_ci ldr r13, .L_imx_ssi_fiq_tx_buffer 4662306a36Sopenharmony_ci 4762306a36Sopenharmony_ci /* shall we send? */ 4862306a36Sopenharmony_ci ldr r11, [r12, #SSI_SIER] 4962306a36Sopenharmony_ci tst r11, #SSI_SIER_TFE0_EN 5062306a36Sopenharmony_ci beq 1f 5162306a36Sopenharmony_ci 5262306a36Sopenharmony_ci /* TX FIFO empty? */ 5362306a36Sopenharmony_ci ldr r11, [r12, #SSI_SISR] 5462306a36Sopenharmony_ci tst r11, #SSI_SISR_TFE0 5562306a36Sopenharmony_ci beq 1f 5662306a36Sopenharmony_ci 5762306a36Sopenharmony_ci mov r10, #0x10000 5862306a36Sopenharmony_ci sub r10, #1 5962306a36Sopenharmony_ci and r10, r10, r8 /* r10: current buffer offset */ 6062306a36Sopenharmony_ci 6162306a36Sopenharmony_ci add r13, r13, r10 6262306a36Sopenharmony_ci 6362306a36Sopenharmony_ci ldrh r11, [r13] 6462306a36Sopenharmony_ci strh r11, [r12, #SSI_STX0] 6562306a36Sopenharmony_ci 6662306a36Sopenharmony_ci ldrh r11, [r13, #2] 6762306a36Sopenharmony_ci strh r11, [r12, #SSI_STX0] 6862306a36Sopenharmony_ci 6962306a36Sopenharmony_ci ldrh r11, [r13, #4] 7062306a36Sopenharmony_ci strh r11, [r12, #SSI_STX0] 7162306a36Sopenharmony_ci 7262306a36Sopenharmony_ci ldrh r11, [r13, #6] 7362306a36Sopenharmony_ci strh r11, [r12, #SSI_STX0] 7462306a36Sopenharmony_ci 7562306a36Sopenharmony_ci add r10, #8 7662306a36Sopenharmony_ci lsr r11, r8, #16 /* r11: buffer size */ 7762306a36Sopenharmony_ci cmp r10, r11 7862306a36Sopenharmony_ci lslgt r8, r11, #16 7962306a36Sopenharmony_ci addle r8, #8 8062306a36Sopenharmony_ci1: 8162306a36Sopenharmony_ci /* RX */ 8262306a36Sopenharmony_ci 8362306a36Sopenharmony_ci /* shall we receive? */ 8462306a36Sopenharmony_ci ldr r11, [r12, #SSI_SIER] 8562306a36Sopenharmony_ci tst r11, #SSI_SIER_RFF0_EN 8662306a36Sopenharmony_ci beq 1f 8762306a36Sopenharmony_ci 8862306a36Sopenharmony_ci /* RX FIFO full? */ 8962306a36Sopenharmony_ci ldr r11, [r12, #SSI_SISR] 9062306a36Sopenharmony_ci tst r11, #SSI_SISR_RFF0 9162306a36Sopenharmony_ci beq 1f 9262306a36Sopenharmony_ci 9362306a36Sopenharmony_ci ldr r13, .L_imx_ssi_fiq_rx_buffer 9462306a36Sopenharmony_ci 9562306a36Sopenharmony_ci mov r10, #0x10000 9662306a36Sopenharmony_ci sub r10, #1 9762306a36Sopenharmony_ci and r10, r10, r9 /* r10: current buffer offset */ 9862306a36Sopenharmony_ci 9962306a36Sopenharmony_ci add r13, r13, r10 10062306a36Sopenharmony_ci 10162306a36Sopenharmony_ci ldr r11, [r12, #SSI_SACNT] 10262306a36Sopenharmony_ci tst r11, #SSI_SACNT_AC97EN 10362306a36Sopenharmony_ci 10462306a36Sopenharmony_ci ldr r11, [r12, #SSI_SRX0] 10562306a36Sopenharmony_ci strh r11, [r13] 10662306a36Sopenharmony_ci 10762306a36Sopenharmony_ci ldr r11, [r12, #SSI_SRX0] 10862306a36Sopenharmony_ci strh r11, [r13, #2] 10962306a36Sopenharmony_ci 11062306a36Sopenharmony_ci /* dummy read to skip slot 12 */ 11162306a36Sopenharmony_ci ldrne r11, [r12, #SSI_SRX0] 11262306a36Sopenharmony_ci 11362306a36Sopenharmony_ci ldr r11, [r12, #SSI_SRX0] 11462306a36Sopenharmony_ci strh r11, [r13, #4] 11562306a36Sopenharmony_ci 11662306a36Sopenharmony_ci ldr r11, [r12, #SSI_SRX0] 11762306a36Sopenharmony_ci strh r11, [r13, #6] 11862306a36Sopenharmony_ci 11962306a36Sopenharmony_ci /* dummy read to skip slot 12 */ 12062306a36Sopenharmony_ci ldrne r11, [r12, #SSI_SRX0] 12162306a36Sopenharmony_ci 12262306a36Sopenharmony_ci add r10, #8 12362306a36Sopenharmony_ci lsr r11, r9, #16 /* r11: buffer size */ 12462306a36Sopenharmony_ci cmp r10, r11 12562306a36Sopenharmony_ci lslgt r9, r11, #16 12662306a36Sopenharmony_ci addle r9, #8 12762306a36Sopenharmony_ci 12862306a36Sopenharmony_ci1: 12962306a36Sopenharmony_ci @ return from FIQ 13062306a36Sopenharmony_ci subs pc, lr, #4 13162306a36Sopenharmony_ci 13262306a36Sopenharmony_ci .align 13362306a36Sopenharmony_ci.L_imx_ssi_fiq_base: 13462306a36Sopenharmony_ciimx_ssi_fiq_base: 13562306a36Sopenharmony_ci .word 0x0 13662306a36Sopenharmony_ci.L_imx_ssi_fiq_rx_buffer: 13762306a36Sopenharmony_ciimx_ssi_fiq_rx_buffer: 13862306a36Sopenharmony_ci .word 0x0 13962306a36Sopenharmony_ci.L_imx_ssi_fiq_tx_buffer: 14062306a36Sopenharmony_ciimx_ssi_fiq_tx_buffer: 14162306a36Sopenharmony_ci .word 0x0 14262306a36Sopenharmony_ci.L_imx_ssi_fiq_end: 14362306a36Sopenharmony_ciimx_ssi_fiq_end: 14462306a36Sopenharmony_ci 145