+++ /dev/null
-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));
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