[brcm63xx] backport upstream spi-bcm63xx fixes

* message pump conversion
* not using stopping state
* setting spi driver mode bits

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@32078 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 289 insertions, 0 deletions

diff --git a/target/linux/brcm63xx/patches-3.3/013-spi-bcm63xx-convert-to-the-pump-message-infrastructu.patch b/target/linux/brcm63xx/patches-3.3/013-spi-bcm63xx-convert-to-the-pump-message-infrastructu.patch
new file mode 100644
index 0000000000..d48225bf08
--- /dev/null
+++ b/target/linux/brcm63xx/patches-3.3/013-spi-bcm63xx-convert-to-the-pump-message-infrastructu.patch
@@ -0,0 +1,289 @@
+From cde4384e1037c15e5dd04c68d19c75798b6281dd Mon Sep 17 00:00:00 2001
+From: Florian Fainelli <florian@openwrt.org>
+Date: Fri, 20 Apr 2012 15:37:33 +0200
+Subject: [PATCH] spi/bcm63xx: convert to the pump message infrastructure
+
+This patch converts the bcm63xx SPI driver to use the SPI infrastructure
+pump message queue. Since we were previously sleeping in the SPI
+driver's transfer() function (which is not allowed) this is now fixed as well.
+
+To complete that conversion a certain number of changes have been made:
+- the transfer len is split into multiple hardware transfers in case its
+  size is bigger than the hardware FIFO size
+- the FIFO refill is no longer done in the interrupt context, which was a
+  bad idea leading to quick interrupt handler re-entrancy
+
+Tested-by: Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com>
+Signed-off-by: Florian Fainelli <florian@openwrt.org>
+Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
+---
+ drivers/spi/spi-bcm63xx.c |  149 +++++++++++++++++++++++++++------------------
+ 1 file changed, 89 insertions(+), 60 deletions(-)
+
+--- a/drivers/spi/spi-bcm63xx.c
++++ b/drivers/spi/spi-bcm63xx.c
+@@ -1,7 +1,7 @@
+ /*
+  * Broadcom BCM63xx SPI controller support
+  *
+- * Copyright (C) 2009-2011 Florian Fainelli <florian@openwrt.org>
++ * Copyright (C) 2009-2012 Florian Fainelli <florian@openwrt.org>
+  * Copyright (C) 2010 Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com>
+  *
+  * This program is free software; you can redistribute it and/or
+@@ -30,6 +30,8 @@
+ #include <linux/spi/spi.h>
+ #include <linux/completion.h>
+ #include <linux/err.h>
++#include <linux/workqueue.h>
++#include <linux/pm_runtime.h>
+ 
+ #include <bcm63xx_dev_spi.h>
+ 
+@@ -96,17 +98,12 @@ static const unsigned bcm63xx_spi_freq_t
+ 	{   391000, SPI_CLK_0_391MHZ }
+ };
+ 
+-static int bcm63xx_spi_setup_transfer(struct spi_device *spi,
+-				      struct spi_transfer *t)
++static int bcm63xx_spi_check_transfer(struct spi_device *spi,
++					struct spi_transfer *t)
+ {
+-	struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
+ 	u8 bits_per_word;
+-	u8 clk_cfg, reg;
+-	u32 hz;
+-	int i;
+ 
+ 	bits_per_word = (t) ? t->bits_per_word : spi->bits_per_word;
+-	hz = (t) ? t->speed_hz : spi->max_speed_hz;
+ 	if (bits_per_word != 8) {
+ 		dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n",
+ 			__func__, bits_per_word);
+@@ -119,6 +116,19 @@ static int bcm63xx_spi_setup_transfer(st
+ 		return -EINVAL;
+ 	}
+ 
++	return 0;
++}
++
++static void bcm63xx_spi_setup_transfer(struct spi_device *spi,
++				      struct spi_transfer *t)
++{
++	struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
++	u32 hz;
++	u8 clk_cfg, reg;
++	int i;
++
++	hz = (t) ? t->speed_hz : spi->max_speed_hz;
++
+ 	/* Find the closest clock configuration */
+ 	for (i = 0; i < SPI_CLK_MASK; i++) {
+ 		if (hz <= bcm63xx_spi_freq_table[i][0]) {
+@@ -139,8 +149,6 @@ static int bcm63xx_spi_setup_transfer(st
+ 	bcm_spi_writeb(bs, reg, SPI_CLK_CFG);
+ 	dev_dbg(&spi->dev, "Setting clock register to %02x (hz %d)\n",
+ 		clk_cfg, hz);
+-
+-	return 0;
+ }
+ 
+ /* the spi->mode bits understood by this driver: */
+@@ -165,7 +173,7 @@ static int bcm63xx_spi_setup(struct spi_
+ 		return -EINVAL;
+ 	}
+ 
+-	ret = bcm63xx_spi_setup_transfer(spi, NULL);
++	ret = bcm63xx_spi_check_transfer(spi, NULL);
+ 	if (ret < 0) {
+ 		dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
+ 			spi->mode & ~MODEBITS);
+@@ -190,28 +198,29 @@ static void bcm63xx_spi_fill_tx_fifo(str
+ 	bs->remaining_bytes -= size;
+ }
+ 
+-static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
++static unsigned int bcm63xx_txrx_bufs(struct spi_device *spi,
++					struct spi_transfer *t)
+ {
+ 	struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
+ 	u16 msg_ctl;
+ 	u16 cmd;
+ 
++	/* Disable the CMD_DONE interrupt */
++	bcm_spi_writeb(bs, 0, SPI_INT_MASK);
++
+ 	dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n",
+ 		t->tx_buf, t->rx_buf, t->len);
+ 
+ 	/* Transmitter is inhibited */
+ 	bs->tx_ptr = t->tx_buf;
+ 	bs->rx_ptr = t->rx_buf;
+-	init_completion(&bs->done);
+ 
+ 	if (t->tx_buf) {
+ 		bs->remaining_bytes = t->len;
+ 		bcm63xx_spi_fill_tx_fifo(bs);
+ 	}
+ 
+-	/* Enable the command done interrupt which
+-	 * we use to determine completion of a command */
+-	bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK);
++	init_completion(&bs->done);
+ 
+ 	/* Fill in the Message control register */
+ 	msg_ctl = (t->len << SPI_BYTE_CNT_SHIFT);
+@@ -230,33 +239,76 @@ static int bcm63xx_txrx_bufs(struct spi_
+ 	cmd |= (0 << SPI_CMD_PREPEND_BYTE_CNT_SHIFT);
+ 	cmd |= (spi->chip_select << SPI_CMD_DEVICE_ID_SHIFT);
+ 	bcm_spi_writew(bs, cmd, SPI_CMD);
+-	wait_for_completion(&bs->done);
+ 
+-	/* Disable the CMD_DONE interrupt */
+-	bcm_spi_writeb(bs, 0, SPI_INT_MASK);
++	/* Enable the CMD_DONE interrupt */
++	bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK);
+ 
+ 	return t->len - bs->remaining_bytes;
+ }
+ 
+-static int bcm63xx_transfer(struct spi_device *spi, struct spi_message *m)
++static int bcm63xx_spi_prepare_transfer(struct spi_master *master)
+ {
+-	struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
+-	struct spi_transfer *t;
+-	int ret = 0;
++	struct bcm63xx_spi *bs = spi_master_get_devdata(master);
+ 
+-	if (unlikely(list_empty(&m->transfers)))
+-		return -EINVAL;
++	pm_runtime_get_sync(&bs->pdev->dev);
+ 
+-	if (bs->stopping)
+-		return -ESHUTDOWN;
++	return 0;
++}
++
++static int bcm63xx_spi_unprepare_transfer(struct spi_master *master)
++{
++	struct bcm63xx_spi *bs = spi_master_get_devdata(master);
++
++	pm_runtime_put(&bs->pdev->dev);
++
++	return 0;
++}
++
++static int bcm63xx_spi_transfer_one(struct spi_master *master,
++					struct spi_message *m)
++{
++	struct bcm63xx_spi *bs = spi_master_get_devdata(master);
++	struct spi_transfer *t;
++	struct spi_device *spi = m->spi;
++	int status = 0;
++	unsigned int timeout = 0;
+ 
+ 	list_for_each_entry(t, &m->transfers, transfer_list) {
+-		ret += bcm63xx_txrx_bufs(spi, t);
+-	}
++		unsigned int len = t->len;
++		u8 rx_tail;
+ 
+-	m->complete(m->context);
++		status = bcm63xx_spi_check_transfer(spi, t);
++		if (status < 0)
++			goto exit;
++
++		/* configure adapter for a new transfer */
++		bcm63xx_spi_setup_transfer(spi, t);
++
++		while (len) {
++			/* send the data */
++			len -= bcm63xx_txrx_bufs(spi, t);
++
++			timeout = wait_for_completion_timeout(&bs->done, HZ);
++			if (!timeout) {
++				status = -ETIMEDOUT;
++				goto exit;
++			}
++
++			/* read out all data */
++			rx_tail = bcm_spi_readb(bs, SPI_RX_TAIL);
++
++			/* Read out all the data */
++			if (rx_tail)
++				memcpy_fromio(bs->rx_ptr, bs->rx_io, rx_tail);
++		}
++
++		m->actual_length += t->len;
++	}
++exit:
++	m->status = status;
++	spi_finalize_current_message(master);
+ 
+-	return ret;
++	return 0;
+ }
+ 
+ /* This driver supports single master mode only. Hence
+@@ -267,39 +319,15 @@ static irqreturn_t bcm63xx_spi_interrupt
+ 	struct spi_master *master = (struct spi_master *)dev_id;
+ 	struct bcm63xx_spi *bs = spi_master_get_devdata(master);
+ 	u8 intr;
+-	u16 cmd;
+ 
+ 	/* Read interupts and clear them immediately */
+ 	intr = bcm_spi_readb(bs, SPI_INT_STATUS);
+ 	bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
+ 	bcm_spi_writeb(bs, 0, SPI_INT_MASK);
+ 
+-	/* A tansfer completed */
+-	if (intr & SPI_INTR_CMD_DONE) {
+-		u8 rx_tail;
+-
+-		rx_tail = bcm_spi_readb(bs, SPI_RX_TAIL);
+-
+-		/* Read out all the data */
+-		if (rx_tail)
+-			memcpy_fromio(bs->rx_ptr, bs->rx_io, rx_tail);
+-
+-		/* See if there is more data to send */
+-		if (bs->remaining_bytes > 0) {
+-			bcm63xx_spi_fill_tx_fifo(bs);
+-
+-			/* Start the transfer */
+-			bcm_spi_writew(bs, SPI_HD_W << SPI_MSG_TYPE_SHIFT,
+-				       SPI_MSG_CTL);
+-			cmd = bcm_spi_readw(bs, SPI_CMD);
+-			cmd |= SPI_CMD_START_IMMEDIATE;
+-			cmd |= (0 << SPI_CMD_PREPEND_BYTE_CNT_SHIFT);
+-			bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK);
+-			bcm_spi_writew(bs, cmd, SPI_CMD);
+-		} else {
+-			complete(&bs->done);
+-		}
+-	}
++	/* A transfer completed */
++	if (intr & SPI_INTR_CMD_DONE)
++		complete(&bs->done);
+ 
+ 	return IRQ_HANDLED;
+ }
+@@ -345,7 +373,6 @@ static int __devinit bcm63xx_spi_probe(s
+ 	}
+ 
+ 	bs = spi_master_get_devdata(master);
+-	init_completion(&bs->done);
+ 
+ 	platform_set_drvdata(pdev, master);
+ 	bs->pdev = pdev;
+@@ -379,7 +406,9 @@ static int __devinit bcm63xx_spi_probe(s
+ 	master->bus_num = pdata->bus_num;
+ 	master->num_chipselect = pdata->num_chipselect;
+ 	master->setup = bcm63xx_spi_setup;
+-	master->transfer = bcm63xx_transfer;
++	master->prepare_transfer_hardware = bcm63xx_spi_prepare_transfer;
++	master->unprepare_transfer_hardware = bcm63xx_spi_unprepare_transfer;
++	master->transfer_one_message = bcm63xx_spi_transfer_one;
+ 	bs->speed_hz = pdata->speed_hz;
+ 	bs->stopping = 0;
+ 	bs->tx_io = (u8 *)(bs->regs + bcm63xx_spireg(SPI_MSG_DATA));