ASoC: Add a new imx-ssi sound driver

The old driver has the number of SSI units in the system hardcoded,
does not make use of the device model and works only on i.MX21/27.

This driver replaces it. It works in DMA mode on i.MX21/27 and using
an FIQ handler on other systems. It also supports AC97 mode of
the SSI units.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Javier Martin <javier.martin@vista-silicon.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 134 insertions, 0 deletions

diff --git a/arch/arm/plat-mxc/ssi-fiq.S b/arch/arm/plat-mxc/ssi-fiq.S
new file mode 100644
index 000000000000..4ddce565b353
--- /dev/null
+++ b/arch/arm/plat-mxc/ssi-fiq.S
@@ -0,0 +1,134 @@
+/*
+ *  Copyright (C) 2009 Sascha Hauer <s.hauer@pengutronix.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+
+/*
+ * r8  = bit 0-15: tx offset, bit 16-31: tx buffer size
+ * r9  = bit 0-15: rx offset, bit 16-31: rx buffer size
+ */
+
+#define SSI_STX0	0x00
+#define SSI_SRX0	0x08
+#define SSI_SISR	0x14
+#define SSI_SIER	0x18
+#define SSI_SACNT	0x38
+
+#define SSI_SACNT_AC97EN	(1 << 0)
+
+#define SSI_SIER_TFE0_EN	(1 << 0)
+#define SSI_SISR_TFE0		(1 << 0)
+#define SSI_SISR_RFF0		(1 << 2)
+#define SSI_SIER_RFF0_EN	(1 << 2)
+
+		.text
+		.global	imx_ssi_fiq_start
+		.global	imx_ssi_fiq_end
+		.global imx_ssi_fiq_base
+		.global imx_ssi_fiq_rx_buffer
+		.global imx_ssi_fiq_tx_buffer
+
+imx_ssi_fiq_start:
+		ldr r12, imx_ssi_fiq_base
+
+		/* TX */
+		ldr r11, imx_ssi_fiq_tx_buffer
+
+		/* shall we send? */
+		ldr r13, [r12, #SSI_SIER]
+		tst r13, #SSI_SIER_TFE0_EN
+		beq 1f
+
+		/* TX FIFO empty? */
+		ldr r13, [r12, #SSI_SISR]
+		tst r13, #SSI_SISR_TFE0
+		beq 1f
+
+		mov r10, #0x10000
+		sub r10, #1
+		and r10, r10, r8	/* r10: current buffer offset */
+
+		add r11, r11, r10
+
+		ldrh r13, [r11]
+		strh r13, [r12, #SSI_STX0]
+
+		ldrh r13, [r11, #2]
+		strh r13, [r12, #SSI_STX0]
+
+		ldrh r13, [r11, #4]
+		strh r13, [r12, #SSI_STX0]
+
+		ldrh r13, [r11, #6]
+		strh r13, [r12, #SSI_STX0]
+
+		add r10, #8
+		lsr r13, r8, #16	/* r13: buffer size */
+		cmp r10, r13
+		lslgt r8, r13, #16
+		addle r8, #8
+1:
+		/* RX */
+
+		/* shall we receive? */
+		ldr r13, [r12, #SSI_SIER]
+		tst r13, #SSI_SIER_RFF0_EN
+		beq 1f
+
+		/* RX FIFO full? */
+		ldr r13, [r12, #SSI_SISR]
+		tst r13, #SSI_SISR_RFF0
+		beq 1f
+
+		ldr r11, imx_ssi_fiq_rx_buffer
+
+		mov r10, #0x10000
+		sub r10, #1
+		and r10, r10, r9	/* r10: current buffer offset */
+
+		add r11, r11, r10
+
+		ldr r13, [r12, #SSI_SACNT]
+		tst r13, #SSI_SACNT_AC97EN
+
+		ldr r13, [r12, #SSI_SRX0]
+		strh r13, [r11]
+
+		ldr r13, [r12, #SSI_SRX0]
+		strh r13, [r11, #2]
+
+		/* dummy read to skip slot 12 */
+		ldrne r13, [r12, #SSI_SRX0]
+
+		ldr r13, [r12, #SSI_SRX0]
+		strh r13, [r11, #4]
+
+		ldr r13, [r12, #SSI_SRX0]
+		strh r13, [r11, #6]
+
+		/* dummy read to skip slot 12 */
+		ldrne r13, [r12, #SSI_SRX0]
+
+		add r10, #8
+		lsr r13, r9, #16	/* r13: buffer size */
+		cmp r10, r13
+		lslgt r9, r13, #16
+		addle r9, #8
+
+1:
+		@ return from FIQ
+		subs	pc, lr, #4
+imx_ssi_fiq_base:
+		.word 0x0
+imx_ssi_fiq_rx_buffer:
+		.word 0x0
+imx_ssi_fiq_tx_buffer:
+		.word 0x0
+imx_ssi_fiq_end:
+