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author | Mark Brown <broonie@kernel.org> | 2019-09-15 12:32:06 +0300 |
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committer | Mark Brown <broonie@kernel.org> | 2019-09-15 12:32:06 +0300 |
commit | b769c5ba8aedc395ed04abe6db84a556d28beec1 (patch) | |
tree | dd00c955f899f65785d60c2b4673785c28054b30 /drivers/spi/spi-uniphier.c | |
parent | 262a2f33454fcecdc2032ca84d6fecdb08233468 (diff) | |
parent | fdeae8f5a2e5eb3fcc9c295bfb28503c3abd4d6e (diff) | |
download | linux-b769c5ba8aedc395ed04abe6db84a556d28beec1.tar.xz |
Merge branch 'spi-5.4' into spi-next
Diffstat (limited to 'drivers/spi/spi-uniphier.c')
-rw-r--r-- | drivers/spi/spi-uniphier.c | 89 |
1 files changed, 68 insertions, 21 deletions
diff --git a/drivers/spi/spi-uniphier.c b/drivers/spi/spi-uniphier.c index 4e99a0f25c29..47cde1864630 100644 --- a/drivers/spi/spi-uniphier.c +++ b/drivers/spi/spi-uniphier.c @@ -7,6 +7,7 @@ #include <linux/bitfield.h> #include <linux/bitops.h> #include <linux/clk.h> +#include <linux/delay.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/module.h> @@ -16,6 +17,7 @@ #include <asm/unaligned.h> #define SSI_TIMEOUT_MS 2000 +#define SSI_POLL_TIMEOUT_US 200 #define SSI_MAX_CLK_DIVIDER 254 #define SSI_MIN_CLK_DIVIDER 4 @@ -227,8 +229,7 @@ static void uniphier_spi_setup_transfer(struct spi_device *spi, priv->speed_hz = t->speed_hz; } - if (!priv->is_save_param) - priv->is_save_param = true; + priv->is_save_param = true; /* reset FIFOs */ val = SSI_FC_TXFFL | SSI_FC_RXFFL; @@ -291,21 +292,23 @@ static void uniphier_spi_recv(struct uniphier_spi_priv *priv) static void uniphier_spi_fill_tx_fifo(struct uniphier_spi_priv *priv) { - unsigned int tx_count; + unsigned int fifo_threshold, fill_bytes; u32 val; - tx_count = DIV_ROUND_UP(priv->tx_bytes, + fifo_threshold = DIV_ROUND_UP(priv->rx_bytes, bytes_per_word(priv->bits_per_word)); - tx_count = min(tx_count, SSI_FIFO_DEPTH); + fifo_threshold = min(fifo_threshold, SSI_FIFO_DEPTH); + + fill_bytes = fifo_threshold - (priv->rx_bytes - priv->tx_bytes); /* set fifo threshold */ val = readl(priv->base + SSI_FC); val &= ~(SSI_FC_TXFTH_MASK | SSI_FC_RXFTH_MASK); - val |= FIELD_PREP(SSI_FC_TXFTH_MASK, tx_count); - val |= FIELD_PREP(SSI_FC_RXFTH_MASK, tx_count); + val |= FIELD_PREP(SSI_FC_TXFTH_MASK, fifo_threshold); + val |= FIELD_PREP(SSI_FC_RXFTH_MASK, fifo_threshold); writel(val, priv->base + SSI_FC); - while (tx_count--) + while (fill_bytes--) uniphier_spi_send(priv); } @@ -324,20 +327,14 @@ static void uniphier_spi_set_cs(struct spi_device *spi, bool enable) writel(val, priv->base + SSI_FPS); } -static int uniphier_spi_transfer_one(struct spi_master *master, - struct spi_device *spi, - struct spi_transfer *t) +static int uniphier_spi_transfer_one_irq(struct spi_master *master, + struct spi_device *spi, + struct spi_transfer *t) { struct uniphier_spi_priv *priv = spi_master_get_devdata(master); struct device *dev = master->dev.parent; unsigned long time_left; - /* Terminate and return success for 0 byte length transfer */ - if (!t->len) - return 0; - - uniphier_spi_setup_transfer(spi, t); - reinit_completion(&priv->xfer_done); uniphier_spi_fill_tx_fifo(priv); @@ -357,6 +354,59 @@ static int uniphier_spi_transfer_one(struct spi_master *master, return priv->error; } +static int uniphier_spi_transfer_one_poll(struct spi_master *master, + struct spi_device *spi, + struct spi_transfer *t) +{ + struct uniphier_spi_priv *priv = spi_master_get_devdata(master); + int loop = SSI_POLL_TIMEOUT_US * 10; + + while (priv->tx_bytes) { + uniphier_spi_fill_tx_fifo(priv); + + while ((priv->rx_bytes - priv->tx_bytes) > 0) { + while (!(readl(priv->base + SSI_SR) & SSI_SR_RNE) + && loop--) + ndelay(100); + + if (loop == -1) + goto irq_transfer; + + uniphier_spi_recv(priv); + } + } + + return 0; + +irq_transfer: + return uniphier_spi_transfer_one_irq(master, spi, t); +} + +static int uniphier_spi_transfer_one(struct spi_master *master, + struct spi_device *spi, + struct spi_transfer *t) +{ + struct uniphier_spi_priv *priv = spi_master_get_devdata(master); + unsigned long threshold; + + /* Terminate and return success for 0 byte length transfer */ + if (!t->len) + return 0; + + uniphier_spi_setup_transfer(spi, t); + + /* + * If the transfer operation will take longer than + * SSI_POLL_TIMEOUT_US, it should use irq. + */ + threshold = DIV_ROUND_UP(SSI_POLL_TIMEOUT_US * priv->speed_hz, + USEC_PER_SEC * BITS_PER_BYTE); + if (t->len > threshold) + return uniphier_spi_transfer_one_irq(master, spi, t); + else + return uniphier_spi_transfer_one_poll(master, spi, t); +} + static int uniphier_spi_prepare_transfer_hardware(struct spi_master *master) { struct uniphier_spi_priv *priv = spi_master_get_devdata(master); @@ -420,7 +470,6 @@ static int uniphier_spi_probe(struct platform_device *pdev) { struct uniphier_spi_priv *priv; struct spi_master *master; - struct resource *res; unsigned long clk_rate; int irq; int ret; @@ -435,8 +484,7 @@ static int uniphier_spi_probe(struct platform_device *pdev) priv->master = master; priv->is_save_param = false; - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - priv->base = devm_ioremap_resource(&pdev->dev, res); + priv->base = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(priv->base)) { ret = PTR_ERR(priv->base); goto out_master_put; @@ -455,7 +503,6 @@ static int uniphier_spi_probe(struct platform_device *pdev) irq = platform_get_irq(pdev, 0); if (irq < 0) { - dev_err(&pdev->dev, "failed to get IRQ\n"); ret = irq; goto out_disable_clk; } |