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