summaryrefslogtreecommitdiff
path: root/drivers/spi/spi-sun6i.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/spi/spi-sun6i.c')
-rw-r--r--drivers/spi/spi-sun6i.c91
1 files changed, 41 insertions, 50 deletions
diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index ecea15534c42..19238e1b76b4 100644
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -7,6 +7,7 @@
* Maxime Ripard <maxime.ripard@free-electrons.com>
*/
+#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/device.h>
@@ -58,10 +59,8 @@
#define SUN6I_FIFO_CTL_TF_RST BIT(31)
#define SUN6I_FIFO_STA_REG 0x1c
-#define SUN6I_FIFO_STA_RF_CNT_MASK 0x7f
-#define SUN6I_FIFO_STA_RF_CNT_BITS 0
-#define SUN6I_FIFO_STA_TF_CNT_MASK 0x7f
-#define SUN6I_FIFO_STA_TF_CNT_BITS 16
+#define SUN6I_FIFO_STA_RF_CNT_MASK GENMASK(7, 0)
+#define SUN6I_FIFO_STA_TF_CNT_MASK GENMASK(23, 16)
#define SUN6I_CLK_CTL_REG 0x24
#define SUN6I_CLK_CTL_CDR2_MASK 0xff
@@ -73,13 +72,10 @@
#define SUN6I_MAX_XFER_SIZE 0xffffff
#define SUN6I_BURST_CNT_REG 0x30
-#define SUN6I_BURST_CNT(cnt) ((cnt) & SUN6I_MAX_XFER_SIZE)
#define SUN6I_XMIT_CNT_REG 0x34
-#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) & SUN6I_MAX_XFER_SIZE)
#define SUN6I_TXDATA_REG 0x200
#define SUN6I_RXDATA_REG 0x300
@@ -109,21 +105,18 @@ 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)
+static inline u32 sun6i_spi_get_rx_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;
+ return FIELD_GET(SUN6I_FIFO_STA_RF_CNT_MASK, reg);
}
-static inline void sun6i_spi_enable_interrupt(struct sun6i_spi *sspi, u32 mask)
+static inline u32 sun6i_spi_get_tx_fifo_count(struct sun6i_spi *sspi)
{
- u32 reg = sun6i_spi_read(sspi, SUN6I_INT_CTL_REG);
+ u32 reg = sun6i_spi_read(sspi, SUN6I_FIFO_STA_REG);
- reg |= mask;
- sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, reg);
+ return FIELD_GET(SUN6I_FIFO_STA_TF_CNT_MASK, reg);
}
static inline void sun6i_spi_disable_interrupt(struct sun6i_spi *sspi, u32 mask)
@@ -134,18 +127,13 @@ static inline void sun6i_spi_disable_interrupt(struct sun6i_spi *sspi, u32 mask)
sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, reg);
}
-static inline void sun6i_spi_drain_fifo(struct sun6i_spi *sspi, int len)
+static inline void sun6i_spi_drain_fifo(struct sun6i_spi *sspi)
{
- u32 reg, cnt;
+ u32 len;
u8 byte;
/* See how much data is available */
- reg = sun6i_spi_read(sspi, SUN6I_FIFO_STA_REG);
- reg &= SUN6I_FIFO_STA_RF_CNT_MASK;
- cnt = reg >> SUN6I_FIFO_STA_RF_CNT_BITS;
-
- if (len > cnt)
- len = cnt;
+ len = sun6i_spi_get_rx_fifo_count(sspi);
while (len--) {
byte = readb(sspi->base_addr + SUN6I_RXDATA_REG);
@@ -154,15 +142,16 @@ 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)
+static inline void sun6i_spi_fill_fifo(struct sun6i_spi *sspi)
{
u32 cnt;
+ int len;
u8 byte;
/* 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);
+ len = min((int)cnt, sspi->len);
while (len--) {
byte = sspi->tx_buf ? *sspi->tx_buf++ : 0;
@@ -198,10 +187,10 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
struct spi_transfer *tfr)
{
struct sun6i_spi *sspi = spi_master_get_devdata(master);
- unsigned int mclk_rate, div, timeout;
+ unsigned int mclk_rate, div, div_cdr1, div_cdr2, timeout;
unsigned int start, end, tx_time;
unsigned int trig_level;
- unsigned int tx_len = 0;
+ unsigned int tx_len = 0, rx_len = 0;
int ret = 0;
u32 reg;
@@ -256,10 +245,12 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
* If it's a TX only transfer, we don't want to fill the RX
* FIFO with bogus data
*/
- if (sspi->rx_buf)
+ if (sspi->rx_buf) {
reg &= ~SUN6I_TFR_CTL_DHB;
- else
+ rx_len = tfr->len;
+ } else {
reg |= SUN6I_TFR_CTL_DHB;
+ }
/* We want to control the chip select manually */
reg |= SUN6I_TFR_CTL_CS_MANUAL;
@@ -287,15 +278,15 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
* First try CDR2, and if we can't reach the expected
* frequency, fall back to CDR1.
*/
- div = mclk_rate / (2 * tfr->speed_hz);
- if (div <= (SUN6I_CLK_CTL_CDR2_MASK + 1)) {
- if (div > 0)
- div--;
-
- reg = SUN6I_CLK_CTL_CDR2(div) | SUN6I_CLK_CTL_DRS;
+ div_cdr1 = DIV_ROUND_UP(mclk_rate, tfr->speed_hz);
+ div_cdr2 = DIV_ROUND_UP(div_cdr1, 2);
+ if (div_cdr2 <= (SUN6I_CLK_CTL_CDR2_MASK + 1)) {
+ reg = SUN6I_CLK_CTL_CDR2(div_cdr2 - 1) | SUN6I_CLK_CTL_DRS;
+ tfr->effective_speed_hz = mclk_rate / (2 * div_cdr2);
} else {
- div = ilog2(mclk_rate) - ilog2(tfr->speed_hz);
+ div = min(SUN6I_CLK_CTL_CDR1_MASK, order_base_2(div_cdr1));
reg = SUN6I_CLK_CTL_CDR1(div);
+ tfr->effective_speed_hz = mclk_rate / (1 << div);
}
sun6i_spi_write(sspi, SUN6I_CLK_CTL_REG, reg);
@@ -305,20 +296,22 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
tx_len = tfr->len;
/* Setup the counters */
- sun6i_spi_write(sspi, SUN6I_BURST_CNT_REG, SUN6I_BURST_CNT(tfr->len));
- sun6i_spi_write(sspi, SUN6I_XMIT_CNT_REG, SUN6I_XMIT_CNT(tx_len));
- sun6i_spi_write(sspi, SUN6I_BURST_CTL_CNT_REG,
- SUN6I_BURST_CTL_CNT_STC(tx_len));
+ sun6i_spi_write(sspi, SUN6I_BURST_CNT_REG, tfr->len);
+ sun6i_spi_write(sspi, SUN6I_XMIT_CNT_REG, tx_len);
+ sun6i_spi_write(sspi, SUN6I_BURST_CTL_CNT_REG, tx_len);
/* Fill the TX FIFO */
- sun6i_spi_fill_fifo(sspi, sspi->fifo_depth);
+ sun6i_spi_fill_fifo(sspi);
/* 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);
+ reg = SUN6I_INT_CTL_TC;
+
+ if (rx_len > sspi->fifo_depth)
+ reg |= SUN6I_INT_CTL_RF_RDY;
if (tx_len > sspi->fifo_depth)
- sun6i_spi_enable_interrupt(sspi, SUN6I_INT_CTL_TF_ERQ);
+ reg |= SUN6I_INT_CTL_TF_ERQ;
+
+ sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, reg);
/* Start the transfer */
reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);
@@ -335,10 +328,8 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
dev_name(&spi->dev), tfr->len, tfr->speed_hz,
jiffies_to_msecs(end - start), tx_time);
ret = -ETIMEDOUT;
- goto out;
}
-out:
sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, 0);
return ret;
@@ -352,14 +343,14 @@ 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);
+ sun6i_spi_drain_fifo(sspi);
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);
+ sun6i_spi_drain_fifo(sspi);
/* Only clear the interrupt _after_ draining the FIFO */
sun6i_spi_write(sspi, SUN6I_INT_STA_REG, SUN6I_INT_CTL_RF_RDY);
return IRQ_HANDLED;
@@ -367,7 +358,7 @@ static irqreturn_t sun6i_spi_handler(int irq, void *dev_id)
/* Transmit FIFO 3/4 empty */
if (status & SUN6I_INT_CTL_TF_ERQ) {
- sun6i_spi_fill_fifo(sspi, SUN6I_FIFO_DEPTH);
+ sun6i_spi_fill_fifo(sspi);
if (!sspi->len)
/* nothing left to transmit */
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-24 20:48:18 +0300