From b490e3704ccee12deb295f96029d68e0daf02feb Mon Sep 17 00:00:00 2001 From: Feng Tang Date: Wed, 20 Jan 2010 13:49:45 -0700 Subject: spi/dw_spi: bug fix in wait_till_not_busy() Make the driver wait at least for 1 jiffie before issuing the warning, no matter what HZ is set to Signed-off-by: Feng Tang Signed-off-by: Grant Likely --- drivers/spi/dw_spi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/spi/dw_spi.c') diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c index 31620fae77be..521d680af289 100644 --- a/drivers/spi/dw_spi.c +++ b/drivers/spi/dw_spi.c @@ -161,7 +161,7 @@ static inline void mrst_spi_debugfs_remove(struct dw_spi *dws) static void wait_till_not_busy(struct dw_spi *dws) { - unsigned long end = jiffies + usecs_to_jiffies(1000); + unsigned long end = jiffies + 1 + usecs_to_jiffies(1000); while (time_before(jiffies, end)) { if (!(dw_readw(dws, sr) & SR_BUSY)) -- cgit v1.2.3 From 552e450929a7298cc8834fd2824a60b2e914f70e Mon Sep 17 00:00:00 2001 From: Feng Tang Date: Wed, 20 Jan 2010 13:49:45 -0700 Subject: spi/dw_spi: refine the IRQ mode working flow Now dw_spi core fully supports 3 transfer modes: pure polling, DMA and IRQ mode. IRQ mode will use the FIFO half empty as the IRQ trigger, so each interface driver need set the fifo_len, so that core driver can handle it properly Signed-off-by: Feng Tang Signed-off-by: Grant Likely --- drivers/spi/dw_spi.c | 64 ++++++++++++++++++++++++++++++++-------------------- 1 file changed, 39 insertions(+), 25 deletions(-) (limited to 'drivers/spi/dw_spi.c') diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c index 521d680af289..1bb709b3920f 100644 --- a/drivers/spi/dw_spi.c +++ b/drivers/spi/dw_spi.c @@ -358,6 +358,8 @@ static void transfer_complete(struct dw_spi *dws) static irqreturn_t interrupt_transfer(struct dw_spi *dws) { u16 irq_status, irq_mask = 0x3f; + u32 int_level = dws->fifo_len / 2; + u32 left; irq_status = dw_readw(dws, isr) & irq_mask; /* Error handling */ @@ -369,22 +371,23 @@ static irqreturn_t interrupt_transfer(struct dw_spi *dws) return IRQ_HANDLED; } - /* INT comes from tx */ - if (dws->tx && (irq_status & SPI_INT_TXEI)) { - while (dws->tx < dws->tx_end) + if (irq_status & SPI_INT_TXEI) { + spi_mask_intr(dws, SPI_INT_TXEI); + + left = (dws->tx_end - dws->tx) / dws->n_bytes; + left = (left > int_level) ? int_level : left; + + while (left--) dws->write(dws); + dws->read(dws); - if (dws->tx == dws->tx_end) { - spi_mask_intr(dws, SPI_INT_TXEI); + /* Re-enable the IRQ if there is still data left to tx */ + if (dws->tx_end > dws->tx) + spi_umask_intr(dws, SPI_INT_TXEI); + else transfer_complete(dws); - } } - /* INT comes from rx */ - if (dws->rx && (irq_status & SPI_INT_RXFI)) { - if (dws->read(dws)) - transfer_complete(dws); - } return IRQ_HANDLED; } @@ -428,6 +431,7 @@ static void pump_transfers(unsigned long data) u8 bits = 0; u8 imask = 0; u8 cs_change = 0; + u16 txint_level = 0; u16 clk_div = 0; u32 speed = 0; u32 cr0 = 0; @@ -438,6 +442,9 @@ static void pump_transfers(unsigned long data) chip = dws->cur_chip; spi = message->spi; + if (unlikely(!chip->clk_div)) + chip->clk_div = dws->max_freq / chip->speed_hz; + if (message->state == ERROR_STATE) { message->status = -EIO; goto early_exit; @@ -492,7 +499,7 @@ static void pump_transfers(unsigned long data) /* clk_div doesn't support odd number */ clk_div = dws->max_freq / speed; - clk_div = (clk_div >> 1) << 1; + clk_div = (clk_div + 1) & 0xfffe; chip->speed_hz = speed; chip->clk_div = clk_div; @@ -535,11 +542,16 @@ static void pump_transfers(unsigned long data) /* Check if current transfer is a DMA transaction */ dws->dma_mapped = map_dma_buffers(dws); + /* + * Interrupt mode + * we only need set the TXEI IRQ, as TX/RX always happen syncronizely + */ if (!dws->dma_mapped && !chip->poll_mode) { - if (dws->rx) - imask |= SPI_INT_RXFI; - if (dws->tx) - imask |= SPI_INT_TXEI; + int templen = dws->len / dws->n_bytes; + txint_level = dws->fifo_len / 2; + txint_level = (templen > txint_level) ? txint_level : templen; + + imask |= SPI_INT_TXEI; dws->transfer_handler = interrupt_transfer; } @@ -549,21 +561,23 @@ static void pump_transfers(unsigned long data) * 2. clk_div is changed * 3. control value changes */ - if (dw_readw(dws, ctrl0) != cr0 || cs_change || clk_div) { + if (dw_readw(dws, ctrl0) != cr0 || cs_change || clk_div || imask) { spi_enable_chip(dws, 0); if (dw_readw(dws, ctrl0) != cr0) dw_writew(dws, ctrl0, cr0); + spi_set_clk(dws, clk_div ? clk_div : chip->clk_div); + spi_chip_sel(dws, spi->chip_select); + /* Set the interrupt mask, for poll mode just diable all int */ spi_mask_intr(dws, 0xff); - if (!chip->poll_mode) + if (imask) spi_umask_intr(dws, imask); + if (txint_level) + dw_writew(dws, txfltr, txint_level); - spi_set_clk(dws, clk_div ? clk_div : chip->clk_div); - spi_chip_sel(dws, spi->chip_select); spi_enable_chip(dws, 1); - if (cs_change) dws->prev_chip = chip; } @@ -712,11 +726,11 @@ static int dw_spi_setup(struct spi_device *spi) } chip->bits_per_word = spi->bits_per_word; + if (!spi->max_speed_hz) { + dev_err(&spi->dev, "No max speed HZ parameter\n"); + return -EINVAL; + } chip->speed_hz = spi->max_speed_hz; - if (chip->speed_hz) - chip->clk_div = 25000000 / chip->speed_hz; - else - chip->clk_div = 8; /* default value */ chip->tmode = 0; /* Tx & Rx */ /* Default SPI mode is SCPOL = 0, SCPH = 0 */ -- cgit v1.2.3 From 99147b5c4167612a987860b661b9f8b79e66b81f Mon Sep 17 00:00:00 2001 From: Grant Likely Date: Wed, 20 Jan 2010 14:03:39 -0700 Subject: spi/dw_spi: fix __init/__devinit section mismatch Section mismatch in reference from the function dw_spi_add_host() to the function init_queue() Signed-off-by: Grant Likely --- drivers/spi/dw_spi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/spi/dw_spi.c') diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c index 1bb709b3920f..f713af8309e3 100644 --- a/drivers/spi/dw_spi.c +++ b/drivers/spi/dw_spi.c @@ -749,7 +749,7 @@ static void dw_spi_cleanup(struct spi_device *spi) kfree(chip); } -static int __init init_queue(struct dw_spi *dws) +static int __devinit init_queue(struct dw_spi *dws) { INIT_LIST_HEAD(&dws->queue); spin_lock_init(&dws->lock); -- cgit v1.2.3 From c587b6fa05106606053fc5e8e344f07cd34ace23 Mon Sep 17 00:00:00 2001 From: Feng Tang Date: Thu, 21 Jan 2010 10:41:10 +0800 Subject: spi/dw_spi: add a FIFO depth detection FIFO depth is configurable for each implementation of DW core, so add a depth detection for those interface drivers who don't set the fifo_len explicitly Signed-off-by: Feng Tang Acked-by: Jean-Hugues Deschenes Signed-off-by: Grant Likely --- drivers/spi/dw_spi.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'drivers/spi/dw_spi.c') diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c index f713af8309e3..d948ef4f3910 100644 --- a/drivers/spi/dw_spi.c +++ b/drivers/spi/dw_spi.c @@ -831,6 +831,22 @@ static void spi_hw_init(struct dw_spi *dws) spi_mask_intr(dws, 0xff); spi_enable_chip(dws, 1); flush(dws); + + /* + * Try to detect the FIFO depth if not set by interface driver, + * the depth could be from 2 to 256 from HW spec + */ + if (!dws->fifo_len) { + u32 fifo; + for (fifo = 2; fifo <= 257; fifo++) { + dw_writew(dws, txfltr, fifo); + if (fifo != dw_readw(dws, txfltr)) + break; + } + + dws->fifo_len = (fifo == 257) ? 0 : fifo; + dw_writew(dws, txfltr, 0); + } } int __devinit dw_spi_add_host(struct dw_spi *dws) -- cgit v1.2.3 From 20a588fcc862df79d8fcafbc41950e3ae93dea09 Mon Sep 17 00:00:00 2001 From: George Shore Date: Thu, 21 Jan 2010 11:40:49 +0000 Subject: spi/dw_spi: add return value to empty mrst_spi_debugfs_init() As per the function signature. Signed-off-by: George Shore Signed-off-by: Grant Likely --- drivers/spi/dw_spi.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/spi/dw_spi.c') diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c index d948ef4f3910..cf945a4cc419 100644 --- a/drivers/spi/dw_spi.c +++ b/drivers/spi/dw_spi.c @@ -152,6 +152,7 @@ static void mrst_spi_debugfs_remove(struct dw_spi *dws) #else static inline int mrst_spi_debugfs_init(struct dw_spi *dws) { + return 0; } static inline void mrst_spi_debugfs_remove(struct dw_spi *dws) -- cgit v1.2.3 From 426c0093d8da4d7b6b0e62cda917b1bae26db4c2 Mon Sep 17 00:00:00 2001 From: George Shore Date: Thu, 21 Jan 2010 11:40:50 +0000 Subject: spi/dw_spi: fixed a spelling typo in a warning message. Signed-off-by: George Shore Signed-off-by: Grant Likely --- drivers/spi/dw_spi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/spi/dw_spi.c') diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c index cf945a4cc419..d0a080a5b598 100644 --- a/drivers/spi/dw_spi.c +++ b/drivers/spi/dw_spi.c @@ -169,7 +169,7 @@ static void wait_till_not_busy(struct dw_spi *dws) return; } dev_err(&dws->master->dev, - "DW SPI: Stutus keeps busy for 1000us after a read/write!\n"); + "DW SPI: Status keeps busy for 1000us after a read/write!\n"); } static void flush(struct dw_spi *dws) -- cgit v1.2.3 From f4aec798ae5a837a1f062e295f9a5f1b00962589 Mon Sep 17 00:00:00 2001 From: George Shore Date: Thu, 21 Jan 2010 11:40:51 +0000 Subject: spi/dw_spi: remove conditional from 'poll_transfer'. The 'poll_transfer' function employs a conditional to test whether the transmit buffer is valid; in doing so, on a receive operation no data is clocked out, thus no data is clocked in and ultimately errors appear. This removes the conditional as the transmit function will be set to a null writer when the transmit buffer is invalid, allowing the driver to clock 0x00 out to the device to receive data from the device. Signed-off-by: George Shore Signed-off-by: Grant Likely --- drivers/spi/dw_spi.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) (limited to 'drivers/spi/dw_spi.c') diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c index d0a080a5b598..3853df5db052 100644 --- a/drivers/spi/dw_spi.c +++ b/drivers/spi/dw_spi.c @@ -408,12 +408,9 @@ static irqreturn_t dw_spi_irq(int irq, void *dev_id) /* Must be called inside pump_transfers() */ static void poll_transfer(struct dw_spi *dws) { - if (dws->tx) { - while (dws->write(dws)) - dws->read(dws); - } + while (dws->write(dws)) + dws->read(dws); - dws->read(dws); transfer_complete(dws); } -- cgit v1.2.3 From 052dc7c45d8f685fb3720a08331ba3e91e87937e Mon Sep 17 00:00:00 2001 From: George Shore Date: Thu, 21 Jan 2010 11:40:52 +0000 Subject: spi/dw_spi: conditional transfer mode changes This allows the switching between transfer modes between 'transmit only', 'receive only' and 'transmit and receive' modes. Due to the design of the SPI block, changing transfer modes requires that the block be disabled; in doing so the chipselect line is inherently deasserted and (usually) the attached device discards its state. Consequentially, switching modes requires that a platform-specific chipselect function has been defined so that the chipselect is not dropped during the change. Signed-off-by: George Shore Signed-off-by: Grant Likely --- drivers/spi/dw_spi.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'drivers/spi/dw_spi.c') diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c index 3853df5db052..e434320fded8 100644 --- a/drivers/spi/dw_spi.c +++ b/drivers/spi/dw_spi.c @@ -537,6 +537,22 @@ static void pump_transfers(unsigned long data) } message->state = RUNNING_STATE; + /* + * Adjust transfer mode if necessary. Requires platform dependent + * chipselect mechanism. + */ + if (dws->cs_control) { + if (dws->rx && dws->tx) + chip->tmode = 0x00; + else if (dws->rx) + chip->tmode = 0x02; + else + chip->tmode = 0x01; + + cr0 &= ~(0x3 << SPI_MODE_OFFSET); + cr0 |= (chip->tmode << SPI_TMOD_OFFSET); + } + /* Check if current transfer is a DMA transaction */ dws->dma_mapped = map_dma_buffers(dws); -- cgit v1.2.3 From 8bcb4a88c5834c6a0fc7140edea32186664fe360 Mon Sep 17 00:00:00 2001 From: Feng Tang Date: Thu, 21 Jan 2010 07:25:38 -0700 Subject: spi/dw_spi: fix missing export of dw_spi_remove_host So that interface drivers could be built as modules Signed-off-by: Feng Tang Signed-off-by: Grant Likely --- drivers/spi/dw_spi.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/spi/dw_spi.c') diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c index e434320fded8..8ed38f1d6c18 100644 --- a/drivers/spi/dw_spi.c +++ b/drivers/spi/dw_spi.c @@ -957,6 +957,7 @@ void __devexit dw_spi_remove_host(struct dw_spi *dws) /* Disconnect from the SPI framework */ spi_unregister_master(dws->master); } +EXPORT_SYMBOL(dw_spi_remove_host); int dw_spi_suspend_host(struct dw_spi *dws) { -- cgit v1.2.3