build/patch/kernel/sun8i-dev/spi-sun6i-allow-large-transfers.patch

201 lines
6 KiB
Diff

diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index 9918a57..64be5aa 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>
@@ -24,6 +25,7 @@
#include <linux/spi/spi.h>
#define SUN6I_FIFO_DEPTH 128
+#define SUN8I_FIFO_DEPTH 64
#define SUN6I_GBL_CTL_REG 0x04
#define SUN6I_GBL_CTL_BUS_ENABLE BIT(0)
@@ -44,6 +46,8 @@
#define SUN6I_TFR_CTL_XCH BIT(31)
#define SUN6I_INT_CTL_REG 0x10
+#define SUN6I_INT_CTL_RF_FUL BIT(2)
+#define SUN6I_INT_CTL_TF_EMP BIT(5)
#define SUN6I_INT_CTL_RF_OVF BIT(8)
#define SUN6I_INT_CTL_TC BIT(12)
@@ -66,11 +70,13 @@
#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)
@@ -90,6 +96,7 @@ 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 +109,31 @@ 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 +156,13 @@ 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 +190,7 @@ 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,
@@ -169,8 +204,7 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
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);
@@ -265,10 +299,16 @@ 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);
+ /* Only enable Tx FIFO interrupt if we really need it */
+ if (tx_len > sspi->fifo_depth)
+ sun6i_spi_write(sspi, SUN6I_INT_CTL_REG,
+ SUN6I_INT_CTL_TC | SUN6I_INT_CTL_RF_FUL | SUN6I_INT_CTL_TF_EMP);
+ else
+ sun6i_spi_write(sspi, SUN6I_INT_CTL_REG,
+ SUN6I_INT_CTL_TC | SUN6I_INT_CTL_RF_FUL);
/* Start the transfer */
reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);
@@ -288,8 +328,6 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
goto out;
}
- sun6i_spi_drain_fifo(sspi, SUN6I_FIFO_DEPTH);
-
out:
sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, 0);
@@ -304,10 +342,33 @@ 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 Full */
+ if (status & SUN6I_INT_CTL_RF_FUL) {
+ sun6i_spi_drain_fifo(sspi, sspi->fifo_depth);
+ /* Only clear the interrupt _after_ draining the FIFO */
+ sun6i_spi_write(sspi, SUN6I_INT_STA_REG, SUN6I_INT_CTL_RF_FUL);
+ return IRQ_HANDLED;
+ }
+
+ /* Transmit FIFO Empty */
+ if (status & SUN6I_INT_CTL_TF_EMP) {
+ sun6i_spi_fill_fifo(sspi, sspi->fifo_depth);
+
+ if (!sspi->len)
+ /* nothing left to transmit */
+ sun6i_spi_disable_interrupt(sspi, SUN6I_INT_CTL_TF_EMP);
+
+ /* Only clear the interrupt _after_ re-seeding the FIFO */
+ sun6i_spi_write(sspi, SUN6I_INT_STA_REG, SUN6I_INT_CTL_TF_EMP);
+
+ return IRQ_HANDLED;
+ }
+
return IRQ_NONE;
}
@@ -398,6 +459,8 @@ 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;
@@ -470,7 +533,8 @@ 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 },
+ { .compatible = "allwinner,sun8i-h3-spi", .data = (void *)SUN8I_FIFO_DEPTH },
{}
};
MODULE_DEVICE_TABLE(of, sun6i_spi_match);