From cde4384e1037c15e5dd04c68d19c75798b6281dd Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Fri, 20 Apr 2012 15:37:33 +0200 Subject: 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 Signed-off-by: Florian Fainelli Signed-off-by: Grant Likely --- drivers/spi/spi-bcm63xx.c | 149 +++++++++++++++++++++++++++------------------- 1 file changed, 89 insertions(+), 60 deletions(-) (limited to 'drivers/spi/spi-bcm63xx.c') diff --git a/drivers/spi/spi-bcm63xx.c b/drivers/spi/spi-bcm63xx.c index f01b2648452e..63b0028a8bd3 100644 --- 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 + * Copyright (C) 2009-2012 Florian Fainelli * Copyright (C) 2010 Tanguy Bouzeloc * * This program is free software; you can redistribute it and/or @@ -30,6 +30,8 @@ #include #include #include +#include +#include #include @@ -96,17 +98,12 @@ static const unsigned bcm63xx_spi_freq_table[SPI_CLK_MASK][2] = { { 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(struct spi_device *spi, 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(struct spi_device *spi, 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_device *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(struct bcm63xx_spi *bs) 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_device *spi, struct spi_transfer *t) 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; - return ret; + /* 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 0; } /* This driver supports single master mode only. Hence @@ -267,39 +319,15 @@ static irqreturn_t bcm63xx_spi_interrupt(int irq, void *dev_id) 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(struct platform_device *pdev) } 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(struct platform_device *pdev) 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)); -- cgit v1.2.3 From 1e41dc0ee2f3807328db95e4f87ff1333245190f Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Fri, 20 Apr 2012 15:37:34 +0200 Subject: spi/bcm63xx: don't use the stopping state We do not need to use a flag to indicate if the master driver is stopping it is sufficient to perform spi master unregistering in the platform driver's remove function. Signed-off-by: Florian Fainelli Signed-off-by: Grant Likely --- drivers/spi/spi-bcm63xx.c | 13 ++----------- 1 file changed, 2 insertions(+), 11 deletions(-) (limited to 'drivers/spi/spi-bcm63xx.c') diff --git a/drivers/spi/spi-bcm63xx.c b/drivers/spi/spi-bcm63xx.c index 63b0028a8bd3..80e5ed34e0d9 100644 --- a/drivers/spi/spi-bcm63xx.c +++ b/drivers/spi/spi-bcm63xx.c @@ -39,8 +39,6 @@ #define DRV_VER "0.1.2" struct bcm63xx_spi { - spinlock_t lock; - int stopping; struct completion done; void __iomem *regs; @@ -161,9 +159,6 @@ static int bcm63xx_spi_setup(struct spi_device *spi) bs = spi_master_get_devdata(spi->master); - if (bs->stopping) - return -ESHUTDOWN; - if (!spi->bits_per_word) spi->bits_per_word = 8; @@ -410,10 +405,8 @@ static int __devinit bcm63xx_spi_probe(struct platform_device *pdev) 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)); bs->rx_io = (const u8 *)(bs->regs + bcm63xx_spireg(SPI_RX_DATA)); - spin_lock_init(&bs->lock); /* Initialize hardware */ clk_enable(bs->clk); @@ -447,18 +440,16 @@ static int __devexit bcm63xx_spi_remove(struct platform_device *pdev) struct spi_master *master = platform_get_drvdata(pdev); struct bcm63xx_spi *bs = spi_master_get_devdata(master); + spi_unregister_master(master); + /* reset spi block */ bcm_spi_writeb(bs, 0, SPI_INT_MASK); - spin_lock(&bs->lock); - bs->stopping = 1; /* HW shutdown */ clk_disable(bs->clk); clk_put(bs->clk); - spin_unlock(&bs->lock); platform_set_drvdata(pdev, 0); - spi_unregister_master(master); return 0; } -- cgit v1.2.3 From 88a3a255a510ed193bf0cc35424761c3c9247586 Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Fri, 20 Apr 2012 15:37:35 +0200 Subject: spi/bcm63xx: set master driver mode_bits. We were not properly advertising the MODE bits supported by this driver, fix that. Signed-off-by: Florian Fainelli Signed-off-by: Grant Likely --- drivers/spi/spi-bcm63xx.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/spi/spi-bcm63xx.c') diff --git a/drivers/spi/spi-bcm63xx.c b/drivers/spi/spi-bcm63xx.c index 80e5ed34e0d9..7491971139a6 100644 --- a/drivers/spi/spi-bcm63xx.c +++ b/drivers/spi/spi-bcm63xx.c @@ -404,6 +404,7 @@ static int __devinit bcm63xx_spi_probe(struct platform_device *pdev) master->prepare_transfer_hardware = bcm63xx_spi_prepare_transfer; master->unprepare_transfer_hardware = bcm63xx_spi_unprepare_transfer; master->transfer_one_message = bcm63xx_spi_transfer_one; + master->mode_bits = MODEBITS; bs->speed_hz = pdata->speed_hz; bs->tx_io = (u8 *)(bs->regs + bcm63xx_spireg(SPI_MSG_DATA)); bs->rx_io = (const u8 *)(bs->regs + bcm63xx_spireg(SPI_RX_DATA)); -- cgit v1.2.3