18c2ecf20Sopenharmony_ci/* SPDX-License-Identifier: GPL-2.0-only */ 28c2ecf20Sopenharmony_ci/* 38c2ecf20Sopenharmony_ci * Copyright (C) 2009 Sascha Hauer <s.hauer@pengutronix.de> 48c2ecf20Sopenharmony_ci */ 58c2ecf20Sopenharmony_ci 68c2ecf20Sopenharmony_ci#include <linux/linkage.h> 78c2ecf20Sopenharmony_ci#include <asm/assembler.h> 88c2ecf20Sopenharmony_ci 98c2ecf20Sopenharmony_ci/* 108c2ecf20Sopenharmony_ci * r8 = bit 0-15: tx offset, bit 16-31: tx buffer size 118c2ecf20Sopenharmony_ci * r9 = bit 0-15: rx offset, bit 16-31: rx buffer size 128c2ecf20Sopenharmony_ci */ 138c2ecf20Sopenharmony_ci 148c2ecf20Sopenharmony_ci#define SSI_STX0 0x00 158c2ecf20Sopenharmony_ci#define SSI_SRX0 0x08 168c2ecf20Sopenharmony_ci#define SSI_SISR 0x14 178c2ecf20Sopenharmony_ci#define SSI_SIER 0x18 188c2ecf20Sopenharmony_ci#define SSI_SACNT 0x38 198c2ecf20Sopenharmony_ci 208c2ecf20Sopenharmony_ci#define SSI_SACNT_AC97EN (1 << 0) 218c2ecf20Sopenharmony_ci 228c2ecf20Sopenharmony_ci#define SSI_SIER_TFE0_EN (1 << 0) 238c2ecf20Sopenharmony_ci#define SSI_SISR_TFE0 (1 << 0) 248c2ecf20Sopenharmony_ci#define SSI_SISR_RFF0 (1 << 2) 258c2ecf20Sopenharmony_ci#define SSI_SIER_RFF0_EN (1 << 2) 268c2ecf20Sopenharmony_ci 278c2ecf20Sopenharmony_ci .text 288c2ecf20Sopenharmony_ci .global imx_ssi_fiq_start 298c2ecf20Sopenharmony_ci .global imx_ssi_fiq_end 308c2ecf20Sopenharmony_ci .global imx_ssi_fiq_base 318c2ecf20Sopenharmony_ci .global imx_ssi_fiq_rx_buffer 328c2ecf20Sopenharmony_ci .global imx_ssi_fiq_tx_buffer 338c2ecf20Sopenharmony_ci 348c2ecf20Sopenharmony_ci/* 358c2ecf20Sopenharmony_ci * imx_ssi_fiq_start is _intentionally_ not marked as a function symbol 368c2ecf20Sopenharmony_ci * using ENDPROC(). imx_ssi_fiq_start and imx_ssi_fiq_end are used to 378c2ecf20Sopenharmony_ci * mark the function body so that it can be copied to the FIQ vector in 388c2ecf20Sopenharmony_ci * the vectors page. imx_ssi_fiq_start should only be called as the result 398c2ecf20Sopenharmony_ci * of an FIQ: calling it directly will not work. 408c2ecf20Sopenharmony_ci */ 418c2ecf20Sopenharmony_ciimx_ssi_fiq_start: 428c2ecf20Sopenharmony_ci ldr r12, .L_imx_ssi_fiq_base 438c2ecf20Sopenharmony_ci 448c2ecf20Sopenharmony_ci /* TX */ 458c2ecf20Sopenharmony_ci ldr r13, .L_imx_ssi_fiq_tx_buffer 468c2ecf20Sopenharmony_ci 478c2ecf20Sopenharmony_ci /* shall we send? */ 488c2ecf20Sopenharmony_ci ldr r11, [r12, #SSI_SIER] 498c2ecf20Sopenharmony_ci tst r11, #SSI_SIER_TFE0_EN 508c2ecf20Sopenharmony_ci beq 1f 518c2ecf20Sopenharmony_ci 528c2ecf20Sopenharmony_ci /* TX FIFO empty? */ 538c2ecf20Sopenharmony_ci ldr r11, [r12, #SSI_SISR] 548c2ecf20Sopenharmony_ci tst r11, #SSI_SISR_TFE0 558c2ecf20Sopenharmony_ci beq 1f 568c2ecf20Sopenharmony_ci 578c2ecf20Sopenharmony_ci mov r10, #0x10000 588c2ecf20Sopenharmony_ci sub r10, #1 598c2ecf20Sopenharmony_ci and r10, r10, r8 /* r10: current buffer offset */ 608c2ecf20Sopenharmony_ci 618c2ecf20Sopenharmony_ci add r13, r13, r10 628c2ecf20Sopenharmony_ci 638c2ecf20Sopenharmony_ci ldrh r11, [r13] 648c2ecf20Sopenharmony_ci strh r11, [r12, #SSI_STX0] 658c2ecf20Sopenharmony_ci 668c2ecf20Sopenharmony_ci ldrh r11, [r13, #2] 678c2ecf20Sopenharmony_ci strh r11, [r12, #SSI_STX0] 688c2ecf20Sopenharmony_ci 698c2ecf20Sopenharmony_ci ldrh r11, [r13, #4] 708c2ecf20Sopenharmony_ci strh r11, [r12, #SSI_STX0] 718c2ecf20Sopenharmony_ci 728c2ecf20Sopenharmony_ci ldrh r11, [r13, #6] 738c2ecf20Sopenharmony_ci strh r11, [r12, #SSI_STX0] 748c2ecf20Sopenharmony_ci 758c2ecf20Sopenharmony_ci add r10, #8 768c2ecf20Sopenharmony_ci lsr r11, r8, #16 /* r11: buffer size */ 778c2ecf20Sopenharmony_ci cmp r10, r11 788c2ecf20Sopenharmony_ci lslgt r8, r11, #16 798c2ecf20Sopenharmony_ci addle r8, #8 808c2ecf20Sopenharmony_ci1: 818c2ecf20Sopenharmony_ci /* RX */ 828c2ecf20Sopenharmony_ci 838c2ecf20Sopenharmony_ci /* shall we receive? */ 848c2ecf20Sopenharmony_ci ldr r11, [r12, #SSI_SIER] 858c2ecf20Sopenharmony_ci tst r11, #SSI_SIER_RFF0_EN 868c2ecf20Sopenharmony_ci beq 1f 878c2ecf20Sopenharmony_ci 888c2ecf20Sopenharmony_ci /* RX FIFO full? */ 898c2ecf20Sopenharmony_ci ldr r11, [r12, #SSI_SISR] 908c2ecf20Sopenharmony_ci tst r11, #SSI_SISR_RFF0 918c2ecf20Sopenharmony_ci beq 1f 928c2ecf20Sopenharmony_ci 938c2ecf20Sopenharmony_ci ldr r13, .L_imx_ssi_fiq_rx_buffer 948c2ecf20Sopenharmony_ci 958c2ecf20Sopenharmony_ci mov r10, #0x10000 968c2ecf20Sopenharmony_ci sub r10, #1 978c2ecf20Sopenharmony_ci and r10, r10, r9 /* r10: current buffer offset */ 988c2ecf20Sopenharmony_ci 998c2ecf20Sopenharmony_ci add r13, r13, r10 1008c2ecf20Sopenharmony_ci 1018c2ecf20Sopenharmony_ci ldr r11, [r12, #SSI_SACNT] 1028c2ecf20Sopenharmony_ci tst r11, #SSI_SACNT_AC97EN 1038c2ecf20Sopenharmony_ci 1048c2ecf20Sopenharmony_ci ldr r11, [r12, #SSI_SRX0] 1058c2ecf20Sopenharmony_ci strh r11, [r13] 1068c2ecf20Sopenharmony_ci 1078c2ecf20Sopenharmony_ci ldr r11, [r12, #SSI_SRX0] 1088c2ecf20Sopenharmony_ci strh r11, [r13, #2] 1098c2ecf20Sopenharmony_ci 1108c2ecf20Sopenharmony_ci /* dummy read to skip slot 12 */ 1118c2ecf20Sopenharmony_ci ldrne r11, [r12, #SSI_SRX0] 1128c2ecf20Sopenharmony_ci 1138c2ecf20Sopenharmony_ci ldr r11, [r12, #SSI_SRX0] 1148c2ecf20Sopenharmony_ci strh r11, [r13, #4] 1158c2ecf20Sopenharmony_ci 1168c2ecf20Sopenharmony_ci ldr r11, [r12, #SSI_SRX0] 1178c2ecf20Sopenharmony_ci strh r11, [r13, #6] 1188c2ecf20Sopenharmony_ci 1198c2ecf20Sopenharmony_ci /* dummy read to skip slot 12 */ 1208c2ecf20Sopenharmony_ci ldrne r11, [r12, #SSI_SRX0] 1218c2ecf20Sopenharmony_ci 1228c2ecf20Sopenharmony_ci add r10, #8 1238c2ecf20Sopenharmony_ci lsr r11, r9, #16 /* r11: buffer size */ 1248c2ecf20Sopenharmony_ci cmp r10, r11 1258c2ecf20Sopenharmony_ci lslgt r9, r11, #16 1268c2ecf20Sopenharmony_ci addle r9, #8 1278c2ecf20Sopenharmony_ci 1288c2ecf20Sopenharmony_ci1: 1298c2ecf20Sopenharmony_ci @ return from FIQ 1308c2ecf20Sopenharmony_ci subs pc, lr, #4 1318c2ecf20Sopenharmony_ci 1328c2ecf20Sopenharmony_ci .align 1338c2ecf20Sopenharmony_ci.L_imx_ssi_fiq_base: 1348c2ecf20Sopenharmony_ciimx_ssi_fiq_base: 1358c2ecf20Sopenharmony_ci .word 0x0 1368c2ecf20Sopenharmony_ci.L_imx_ssi_fiq_rx_buffer: 1378c2ecf20Sopenharmony_ciimx_ssi_fiq_rx_buffer: 1388c2ecf20Sopenharmony_ci .word 0x0 1398c2ecf20Sopenharmony_ci.L_imx_ssi_fiq_tx_buffer: 1408c2ecf20Sopenharmony_ciimx_ssi_fiq_tx_buffer: 1418c2ecf20Sopenharmony_ci .word 0x0 1428c2ecf20Sopenharmony_ci.L_imx_ssi_fiq_end: 1438c2ecf20Sopenharmony_ciimx_ssi_fiq_end: 1448c2ecf20Sopenharmony_ci 145