diff options
author | Klaus Goger <klaus.goger@theobroma-systems.com> | 2016-06-13 17:46:49 +0000 |
---|---|---|
committer | Klaus Goger <klaus.goger@theobroma-systems.com> | 2017-06-12 11:39:07 +0200 |
commit | 822a55305e882798cdf0f8549fb2cfa9ae03e1d3 (patch) | |
tree | 2f551c574bcc24f6e651f1d73b2663386b672638 | |
parent | 5694380f71dd41e16085876e0513dea643ebe378 (diff) |
spi: sun6i: backport from 4.12 to 4.6
backport from mainline spi driver to 4.6 +
794912cff6dba8b5e93948243299bb0b2cb11277
to support transfers larger than FIFO size.
Signed-off-by: Klaus Goger <klaus.goger@theobroma-systems.com>
-rw-r--r-- | drivers/spi/spi-sun6i.c | 112 |
1 files changed, 99 insertions, 13 deletions
diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c index 6fa6ff12ae61..0a0e72424f7a 100644 --- a/drivers/spi/spi-sun6i.c +++ b/drivers/spi/spi-sun6i.c @@ -17,6 +17,7 @@ #include <linux/interrupt.h> #include <linux/io.h> #include <linux/module.h> +#include <linux/of_device.h> #include <linux/platform_device.h> #include <linux/pm_runtime.h> #include <linux/reset.h> @@ -44,13 +45,19 @@ #define SUN6I_TFR_CTL_XCH BIT(31) #define SUN6I_INT_CTL_REG 0x10 +#define SUN6I_INT_CTL_RF_RDY BIT(0) +#define SUN6I_INT_CTL_TF_ERQ BIT(4) #define SUN6I_INT_CTL_RF_OVF BIT(8) #define SUN6I_INT_CTL_TC BIT(12) #define SUN6I_INT_STA_REG 0x14 #define SUN6I_FIFO_CTL_REG 0x18 +#define SUN6I_FIFO_CTL_RF_RDY_TRIG_LEVEL_MASK 0xff +#define SUN6I_FIFO_CTL_RF_RDY_TRIG_LEVEL_BITS 0 #define SUN6I_FIFO_CTL_RF_RST BIT(15) +#define SUN6I_FIFO_CTL_TF_ERQ_TRIG_LEVEL_MASK 0xff +#define SUN6I_FIFO_CTL_TF_ERQ_TRIG_LEVEL_BITS 16 #define SUN6I_FIFO_CTL_TF_RST BIT(31) #define SUN6I_FIFO_STA_REG 0x1c @@ -66,14 +73,16 @@ #define SUN6I_CLK_CTL_CDR1(div) (((div) & SUN6I_CLK_CTL_CDR1_MASK) << 8) #define SUN6I_CLK_CTL_DRS BIT(12) +#define SUN6I_MAX_XFER_SIZE 0xffffff + #define SUN6I_BURST_CNT_REG 0x30 -#define SUN6I_BURST_CNT(cnt) ((cnt) & 0xffffff) +#define SUN6I_BURST_CNT(cnt) ((cnt) & SUN6I_MAX_XFER_SIZE) #define SUN6I_XMIT_CNT_REG 0x34 -#define SUN6I_XMIT_CNT(cnt) ((cnt) & 0xffffff) +#define SUN6I_XMIT_CNT(cnt) ((cnt) & SUN6I_MAX_XFER_SIZE) #define SUN6I_BURST_CTL_CNT_REG 0x38 -#define SUN6I_BURST_CTL_CNT_STC(cnt) ((cnt) & 0xffffff) +#define SUN6I_BURST_CTL_CNT_STC(cnt) ((cnt) & SUN6I_MAX_XFER_SIZE) #define SUN6I_TXDATA_REG 0x200 #define SUN6I_RXDATA_REG 0x300 @@ -90,6 +99,7 @@ struct sun6i_spi { const u8 *tx_buf; u8 *rx_buf; int len; + unsigned long fifo_depth; }; static inline u32 sun6i_spi_read(struct sun6i_spi *sspi, u32 reg) @@ -102,6 +112,31 @@ static inline void sun6i_spi_write(struct sun6i_spi *sspi, u32 reg, u32 value) writel(value, sspi->base_addr + reg); } +static inline u32 sun6i_spi_get_tx_fifo_count(struct sun6i_spi *sspi) +{ + u32 reg = sun6i_spi_read(sspi, SUN6I_FIFO_STA_REG); + + reg >>= SUN6I_FIFO_STA_TF_CNT_BITS; + + return reg & SUN6I_FIFO_STA_TF_CNT_MASK; +} + +static inline void sun6i_spi_enable_interrupt(struct sun6i_spi *sspi, u32 mask) +{ + u32 reg = sun6i_spi_read(sspi, SUN6I_INT_CTL_REG); + + reg |= mask; + sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, reg); +} + +static inline void sun6i_spi_disable_interrupt(struct sun6i_spi *sspi, u32 mask) +{ + u32 reg = sun6i_spi_read(sspi, SUN6I_INT_CTL_REG); + + reg &= ~mask; + sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, reg); +} + static inline void sun6i_spi_drain_fifo(struct sun6i_spi *sspi, int len) { u32 reg, cnt; @@ -124,10 +159,13 @@ static inline void sun6i_spi_drain_fifo(struct sun6i_spi *sspi, int len) static inline void sun6i_spi_fill_fifo(struct sun6i_spi *sspi, int len) { + u32 cnt; u8 byte; - if (len > sspi->len) - len = sspi->len; + /* See how much data we can fit */ + cnt = sspi->fifo_depth - sun6i_spi_get_tx_fifo_count(sspi); + + len = min3(len, (int)cnt, sspi->len); while (len--) { byte = sspi->tx_buf ? *sspi->tx_buf++ : 0; @@ -155,7 +193,7 @@ static void sun6i_spi_set_cs(struct spi_device *spi, bool enable) static size_t sun6i_spi_max_transfer_size(struct spi_device *spi) { - return SUN6I_FIFO_DEPTH - 1; + return SUN6I_MAX_XFER_SIZE - 1; } static int sun6i_spi_transfer_one(struct spi_master *master, @@ -164,12 +202,13 @@ static int sun6i_spi_transfer_one(struct spi_master *master, { struct sun6i_spi *sspi = spi_master_get_devdata(master); unsigned int mclk_rate, div, timeout; + unsigned int start, end, tx_time; + unsigned int trig_level; unsigned int tx_len = 0; int ret = 0; u32 reg; - /* We don't support transfer larger than the FIFO */ - if (tfr->len > SUN6I_FIFO_DEPTH) + if (tfr->len > SUN6I_MAX_XFER_SIZE) return -EINVAL; reinit_completion(&sspi->done); @@ -185,6 +224,17 @@ static int sun6i_spi_transfer_one(struct spi_master *master, SUN6I_FIFO_CTL_RF_RST | SUN6I_FIFO_CTL_TF_RST); /* + * Setup FIFO interrupt trigger level + * Here we choose 3/4 of the full fifo depth, as it's the hardcoded + * value used in old generation of Allwinner SPI controller. + * (See spi-sun4i.c) + */ + trig_level = sspi->fifo_depth / 4 * 3; + sun6i_spi_write(sspi, SUN6I_FIFO_CTL_REG, + (trig_level << SUN6I_FIFO_CTL_RF_RDY_TRIG_LEVEL_BITS) | + (trig_level << SUN6I_FIFO_CTL_TF_ERQ_TRIG_LEVEL_BITS)); + + /* * Setup the transfer control register: Chip Select, * polarities, etc. */ @@ -264,24 +314,33 @@ static int sun6i_spi_transfer_one(struct spi_master *master, SUN6I_BURST_CTL_CNT_STC(tx_len)); /* Fill the TX FIFO */ - sun6i_spi_fill_fifo(sspi, SUN6I_FIFO_DEPTH); + sun6i_spi_fill_fifo(sspi, sspi->fifo_depth); /* Enable the interrupts */ sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, SUN6I_INT_CTL_TC); + sun6i_spi_enable_interrupt(sspi, SUN6I_INT_CTL_TC | + SUN6I_INT_CTL_RF_RDY); + if (tx_len > sspi->fifo_depth) + sun6i_spi_enable_interrupt(sspi, SUN6I_INT_CTL_TF_ERQ); /* Start the transfer */ reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG); sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg | SUN6I_TFR_CTL_XCH); + tx_time = max(tfr->len * 8 * 2 / (tfr->speed_hz / 1000), 100U); + start = jiffies; timeout = wait_for_completion_timeout(&sspi->done, - msecs_to_jiffies(1000)); + msecs_to_jiffies(tx_time)); + end = jiffies; if (!timeout) { + dev_warn(&master->dev, + "%s: timeout transferring %u bytes@%iHz for %i(%i)ms", + dev_name(&spi->dev), tfr->len, tfr->speed_hz, + jiffies_to_msecs(end - start), tx_time); ret = -ETIMEDOUT; goto out; } - sun6i_spi_drain_fifo(sspi, SUN6I_FIFO_DEPTH); - out: sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, 0); @@ -296,10 +355,33 @@ static irqreturn_t sun6i_spi_handler(int irq, void *dev_id) /* Transfer complete */ if (status & SUN6I_INT_CTL_TC) { sun6i_spi_write(sspi, SUN6I_INT_STA_REG, SUN6I_INT_CTL_TC); + sun6i_spi_drain_fifo(sspi, sspi->fifo_depth); complete(&sspi->done); return IRQ_HANDLED; } + /* Receive FIFO 3/4 full */ + if (status & SUN6I_INT_CTL_RF_RDY) { + sun6i_spi_drain_fifo(sspi, SUN6I_FIFO_DEPTH); + /* Only clear the interrupt _after_ draining the FIFO */ + sun6i_spi_write(sspi, SUN6I_INT_STA_REG, SUN6I_INT_CTL_RF_RDY); + return IRQ_HANDLED; + } + + /* Transmit FIFO 3/4 empty */ + if (status & SUN6I_INT_CTL_TF_ERQ) { + sun6i_spi_fill_fifo(sspi, SUN6I_FIFO_DEPTH); + + if (!sspi->len) + /* nothing left to transmit */ + sun6i_spi_disable_interrupt(sspi, SUN6I_INT_CTL_TF_ERQ); + + /* Only clear the interrupt _after_ re-seeding the FIFO */ + sun6i_spi_write(sspi, SUN6I_INT_STA_REG, SUN6I_INT_CTL_TF_ERQ); + + return IRQ_HANDLED; + } + return IRQ_NONE; } @@ -390,6 +472,10 @@ static int sun6i_spi_probe(struct platform_device *pdev) } sspi->master = master; + sspi->fifo_depth = (unsigned long)of_device_get_match_data(&pdev->dev); + + master->max_speed_hz = 100 * 1000 * 1000; + master->min_speed_hz = 3 * 1000; master->set_cs = sun6i_spi_set_cs; master->transfer_one = sun6i_spi_transfer_one; master->num_chipselect = 4; @@ -460,7 +546,7 @@ static int sun6i_spi_remove(struct platform_device *pdev) } static const struct of_device_id sun6i_spi_match[] = { - { .compatible = "allwinner,sun6i-a31-spi", }, + { .compatible = "allwinner,sun6i-a31-spi", .data = (void *)SUN6I_FIFO_DEPTH }, {} }; MODULE_DEVICE_TABLE(of, sun6i_spi_match); |