[PATCH/RFC 3/6] spi: sh-msiof: Add slave mode support
From: Geert Uytterhoeven
Date: Wed Jun 22 2016 - 09:43:43 EST
From: Hisashi Nakamura <hisashi.nakamura.ak@xxxxxxxxxxx>
Add slave mode support to the MSIOF driver.
For now this only supports the transmission of messages with a size
that is known in advance.
Signed-off-by: Hisashi Nakamura <hisashi.nakamura.ak@xxxxxxxxxxx>
Signed-off-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@xxxxxxxxxxx>
[geert: Timeout handling cleanup, spi core integration, rewording]
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
drivers/spi/spi-sh-msiof.c | 52 ++++++++++++++++++++++++++++++++++----------
include/linux/spi/sh_msiof.h | 6 +++++
2 files changed, 46 insertions(+), 12 deletions(-)
diff --git a/drivers/spi/spi-sh-msiof.c b/drivers/spi/spi-sh-msiof.c
index 0f83ad1d5a5858dd..afde3fe12bce844f 100644
--- a/drivers/spi/spi-sh-msiof.c
+++ b/drivers/spi/spi-sh-msiof.c
@@ -3,6 +3,7 @@
*
* Copyright (c) 2009 Magnus Damm
* Copyright (C) 2014 Glider bvba
+ * Copyright (C) 2014 Renesas Electronics Corporation
*
* 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
@@ -33,7 +34,6 @@
#include <asm/unaligned.h>
-
struct sh_msiof_chipdata {
u16 tx_fifo_size;
u16 rx_fifo_size;
@@ -334,7 +334,10 @@ static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p,
tmp |= !cs_high << MDR1_SYNCAC_SHIFT;
tmp |= lsb_first << MDR1_BITLSB_SHIFT;
tmp |= sh_msiof_spi_get_dtdl_and_syncdl(p);
- sh_msiof_write(p, TMDR1, tmp | MDR1_TRMD | TMDR1_PCON);
+ if (p->master->flags & SPI_MASTER_IS_SLAVE)
+ sh_msiof_write(p, TMDR1, tmp | TMDR1_PCON);
+ else
+ sh_msiof_write(p, TMDR1, tmp | MDR1_TRMD | TMDR1_PCON);
if (p->master->flags & SPI_MASTER_MUST_TX) {
/* These bits are reserved if RX needs TX */
tmp &= ~0x0000ffff;
@@ -561,17 +564,19 @@ static int sh_msiof_prepare_message(struct spi_master *master,
static int sh_msiof_spi_start(struct sh_msiof_spi_priv *p, void *rx_buf)
{
- int ret;
+ bool slave = p->master->flags & SPI_MASTER_IS_SLAVE;
+ int ret = 0;
/* setup clock and rx/tx signals */
- ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TSCKE);
+ if (!slave)
+ ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TSCKE);
if (rx_buf && !ret)
ret = sh_msiof_modify_ctr_wait(p, 0, CTR_RXE);
if (!ret)
ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TXE);
/* start by setting frame bit */
- if (!ret)
+ if (!ret && !slave)
ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TFSE);
return ret;
@@ -579,15 +584,17 @@ static int sh_msiof_spi_start(struct sh_msiof_spi_priv *p, void *rx_buf)
static int sh_msiof_spi_stop(struct sh_msiof_spi_priv *p, void *rx_buf)
{
- int ret;
+ bool slave = p->master->flags & SPI_MASTER_IS_SLAVE;
+ int ret = 0;
/* shut down frame, rx/tx and clock signals */
- ret = sh_msiof_modify_ctr_wait(p, CTR_TFSE, 0);
+ if (!slave)
+ ret = sh_msiof_modify_ctr_wait(p, CTR_TFSE, 0);
if (!ret)
ret = sh_msiof_modify_ctr_wait(p, CTR_TXE, 0);
if (rx_buf && !ret)
ret = sh_msiof_modify_ctr_wait(p, CTR_RXE, 0);
- if (!ret)
+ if (!ret && !slave)
ret = sh_msiof_modify_ctr_wait(p, CTR_TSCKE, 0);
return ret;
@@ -633,7 +640,11 @@ static int sh_msiof_spi_txrx_once(struct sh_msiof_spi_priv *p,
}
/* wait for tx fifo to be emptied / rx fifo to be filled */
- if (!wait_for_completion_timeout(&p->done, HZ)) {
+ if (p->master->flags & SPI_MASTER_IS_SLAVE)
+ ret = !wait_for_completion_interruptible(&p->done);
+ else
+ ret = wait_for_completion_timeout(&p->done, HZ);
+ if (!ret) {
dev_err(&p->pdev->dev, "PIO timeout\n");
ret = -ETIMEDOUT;
goto stop_reset;
@@ -743,7 +754,11 @@ static int sh_msiof_dma_once(struct sh_msiof_spi_priv *p, const void *tx,
}
/* wait for tx fifo to be emptied / rx fifo to be filled */
- if (!wait_for_completion_timeout(&p->done, HZ)) {
+ if (p->master->flags & SPI_MASTER_IS_SLAVE)
+ ret = !wait_for_completion_interruptible(&p->done);
+ else
+ ret = wait_for_completion_timeout(&p->done, HZ);
+ if (!ret) {
dev_err(&p->pdev->dev, "DMA timeout\n");
ret = -ETIMEDOUT;
goto stop_reset;
@@ -840,7 +855,8 @@ static int sh_msiof_transfer_one(struct spi_master *master,
int ret;
/* setup clocks (clock already enabled in chipselect()) */
- sh_msiof_spi_set_clk_regs(p, clk_get_rate(p->clk), t->speed_hz);
+ if (!(p->master->flags & SPI_MASTER_IS_SLAVE))
+ sh_msiof_spi_set_clk_regs(p, clk_get_rate(p->clk), t->speed_hz);
while (master->dma_tx && len > 15) {
/*
@@ -986,14 +1002,24 @@ static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
{
struct sh_msiof_spi_info *info;
struct device_node *np = dev->of_node;
+ struct device_node *slave;
u32 num_cs = 1;
info = devm_kzalloc(dev, sizeof(struct sh_msiof_spi_info), GFP_KERNEL);
if (!info)
return NULL;
+ slave = of_get_child_by_name(np, "slave");
+ if (slave) {
+ info->mode = MSIOF_SPI_SLAVE;
+ of_node_put(slave);
+ } else {
+ info->mode = MSIOF_SPI_MASTER;
+ }
+
/* Parse the MSIOF properties */
- of_property_read_u32(np, "num-cs", &num_cs);
+ if (info->mode == MSIOF_SPI_MASTER)
+ of_property_read_u32(np, "num-cs", &num_cs);
of_property_read_u32(np, "renesas,tx-fifo-size",
&info->tx_fifo_override);
of_property_read_u32(np, "renesas,rx-fifo-size",
@@ -1228,6 +1254,8 @@ static int sh_msiof_spi_probe(struct platform_device *pdev)
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
master->mode_bits |= SPI_LSB_FIRST | SPI_3WIRE;
master->flags = chipdata->master_flags;
+ if (p->info->mode == MSIOF_SPI_SLAVE)
+ master->flags |= SPI_MASTER_IS_SLAVE;
master->bus_num = pdev->id;
master->dev.of_node = pdev->dev.of_node;
master->num_chipselect = p->info->num_chipselect;
diff --git a/include/linux/spi/sh_msiof.h b/include/linux/spi/sh_msiof.h
index b087a85f5f72a351..f74b581f242f8c43 100644
--- a/include/linux/spi/sh_msiof.h
+++ b/include/linux/spi/sh_msiof.h
@@ -1,10 +1,16 @@
#ifndef __SPI_SH_MSIOF_H__
#define __SPI_SH_MSIOF_H__
+enum {
+ MSIOF_SPI_MASTER,
+ MSIOF_SPI_SLAVE,
+};
+
struct sh_msiof_spi_info {
int tx_fifo_override;
int rx_fifo_override;
u16 num_chipselect;
+ int mode;
unsigned int dma_tx_id;
unsigned int dma_rx_id;
u32 dtdl;
--
1.9.1