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path: root/drivers/spi/spi-axi-spi-engine.c
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Diffstat (limited to 'drivers/spi/spi-axi-spi-engine.c')
-rw-r--r--drivers/spi/spi-axi-spi-engine.c91
1 files changed, 85 insertions, 6 deletions
diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c
index da9840957778..8cc19934b48b 100644
--- a/drivers/spi/spi-axi-spi-engine.c
+++ b/drivers/spi/spi-axi-spi-engine.c
@@ -14,6 +14,7 @@
#include <linux/fpga/adi-axi-common.h>
#include <linux/interrupt.h>
#include <linux/io.h>
+#include <linux/iopoll.h>
#include <linux/of.h>
#include <linux/module.h>
#include <linux/overflow.h>
@@ -140,6 +141,8 @@ struct spi_engine_offload {
struct spi_engine *spi_engine;
unsigned long flags;
unsigned int offload_num;
+ unsigned int spi_mode_config;
+ u8 bits_per_word;
};
struct spi_engine {
@@ -159,6 +162,7 @@ struct spi_engine {
unsigned int offload_sdo_mem_size;
struct spi_offload *offload;
u32 offload_caps;
+ bool offload_requires_sync;
};
static void spi_engine_program_add_cmd(struct spi_engine_program *p,
@@ -265,6 +269,8 @@ static int spi_engine_precompile_message(struct spi_message *msg)
{
unsigned int clk_div, max_hz = msg->spi->controller->max_speed_hz;
struct spi_transfer *xfer;
+ u8 min_bits_per_word = U8_MAX;
+ u8 max_bits_per_word = 0;
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
/* If we have an offload transfer, we can't rx to buffer */
@@ -273,6 +279,24 @@ static int spi_engine_precompile_message(struct spi_message *msg)
clk_div = DIV_ROUND_UP(max_hz, xfer->speed_hz);
xfer->effective_speed_hz = max_hz / min(clk_div, 256U);
+
+ if (xfer->len) {
+ min_bits_per_word = min(min_bits_per_word, xfer->bits_per_word);
+ max_bits_per_word = max(max_bits_per_word, xfer->bits_per_word);
+ }
+ }
+
+ /*
+ * If all xfers in the message use the same bits_per_word, we can
+ * provide some optimization when using SPI offload.
+ */
+ if (msg->offload) {
+ struct spi_engine_offload *priv = msg->offload->priv;
+
+ if (min_bits_per_word == max_bits_per_word)
+ priv->bits_per_word = min_bits_per_word;
+ else
+ priv->bits_per_word = 0;
}
return 0;
@@ -283,6 +307,7 @@ static void spi_engine_compile_message(struct spi_message *msg, bool dry,
{
struct spi_device *spi = msg->spi;
struct spi_controller *host = spi->controller;
+ struct spi_engine_offload *priv;
struct spi_transfer *xfer;
int clk_div, new_clk_div, inst_ns;
bool keep_cs = false;
@@ -296,9 +321,24 @@ static void spi_engine_compile_message(struct spi_message *msg, bool dry,
clk_div = 1;
- spi_engine_program_add_cmd(p, dry,
- SPI_ENGINE_CMD_WRITE(SPI_ENGINE_CMD_REG_CONFIG,
- spi_engine_get_config(spi)));
+ /*
+ * As an optimization, SPI offload sets once this when the offload is
+ * enabled instead of repeating the instruction in each message.
+ */
+ if (msg->offload) {
+ priv = msg->offload->priv;
+ priv->spi_mode_config = spi_engine_get_config(spi);
+
+ /*
+ * If all xfers use the same bits_per_word, it can be optimized
+ * in the same way.
+ */
+ bits_per_word = priv->bits_per_word;
+ } else {
+ spi_engine_program_add_cmd(p, dry,
+ SPI_ENGINE_CMD_WRITE(SPI_ENGINE_CMD_REG_CONFIG,
+ spi_engine_get_config(spi)));
+ }
xfer = list_first_entry(&msg->transfers, struct spi_transfer, transfer_list);
spi_engine_gen_cs(p, dry, spi, !xfer->cs_off);
@@ -663,6 +703,8 @@ static void spi_engine_offload_unprepare(struct spi_offload *offload)
static int spi_engine_optimize_message(struct spi_message *msg)
{
+ struct spi_controller *host = msg->spi->controller;
+ struct spi_engine *spi_engine = spi_controller_get_devdata(host);
struct spi_engine_program p_dry, *p;
int ret;
@@ -679,8 +721,13 @@ static int spi_engine_optimize_message(struct spi_message *msg)
spi_engine_compile_message(msg, false, p);
- spi_engine_program_add_cmd(p, false, SPI_ENGINE_CMD_SYNC(
- msg->offload ? 0 : AXI_SPI_ENGINE_CUR_MSG_SYNC_ID));
+ /*
+ * Non-offload needs SYNC for completion interrupt. Older versions of
+ * the IP core also need SYNC for offload to work properly.
+ */
+ if (!msg->offload || spi_engine->offload_requires_sync)
+ spi_engine_program_add_cmd(p, false, SPI_ENGINE_CMD_SYNC(
+ msg->offload ? 0 : AXI_SPI_ENGINE_CUR_MSG_SYNC_ID));
msg->opt_state = p;
@@ -739,12 +786,16 @@ static int spi_engine_setup(struct spi_device *device)
{
struct spi_controller *host = device->controller;
struct spi_engine *spi_engine = spi_controller_get_devdata(host);
+ unsigned int reg;
if (device->mode & SPI_CS_HIGH)
spi_engine->cs_inv |= BIT(spi_get_chipselect(device, 0));
else
spi_engine->cs_inv &= ~BIT(spi_get_chipselect(device, 0));
+ writel_relaxed(SPI_ENGINE_CMD_SYNC(0),
+ spi_engine->base + SPI_ENGINE_REG_CMD_FIFO);
+
writel_relaxed(SPI_ENGINE_CMD_CS_INV(spi_engine->cs_inv),
spi_engine->base + SPI_ENGINE_REG_CMD_FIFO);
@@ -755,7 +806,11 @@ static int spi_engine_setup(struct spi_device *device)
writel_relaxed(SPI_ENGINE_CMD_ASSERT(0, 0xff),
spi_engine->base + SPI_ENGINE_REG_CMD_FIFO);
- return 0;
+ writel_relaxed(SPI_ENGINE_CMD_SYNC(1),
+ spi_engine->base + SPI_ENGINE_REG_CMD_FIFO);
+
+ return readl_relaxed_poll_timeout(spi_engine->base + SPI_ENGINE_REG_SYNC_ID,
+ reg, reg == 1, 1, 1000);
}
static int spi_engine_transfer_one_message(struct spi_controller *host,
@@ -833,6 +888,27 @@ static int spi_engine_trigger_enable(struct spi_offload *offload)
struct spi_engine_offload *priv = offload->priv;
struct spi_engine *spi_engine = priv->spi_engine;
unsigned int reg;
+ int ret;
+
+ writel_relaxed(SPI_ENGINE_CMD_SYNC(0),
+ spi_engine->base + SPI_ENGINE_REG_CMD_FIFO);
+
+ writel_relaxed(SPI_ENGINE_CMD_WRITE(SPI_ENGINE_CMD_REG_CONFIG,
+ priv->spi_mode_config),
+ spi_engine->base + SPI_ENGINE_REG_CMD_FIFO);
+
+ if (priv->bits_per_word)
+ writel_relaxed(SPI_ENGINE_CMD_WRITE(SPI_ENGINE_CMD_REG_XFER_BITS,
+ priv->bits_per_word),
+ spi_engine->base + SPI_ENGINE_REG_CMD_FIFO);
+
+ writel_relaxed(SPI_ENGINE_CMD_SYNC(1),
+ spi_engine->base + SPI_ENGINE_REG_CMD_FIFO);
+
+ ret = readl_relaxed_poll_timeout(spi_engine->base + SPI_ENGINE_REG_SYNC_ID,
+ reg, reg == 1, 1, 1000);
+ if (ret)
+ return ret;
reg = readl_relaxed(spi_engine->base +
SPI_ENGINE_REG_OFFLOAD_CTRL(priv->offload_num));
@@ -987,6 +1063,9 @@ static int spi_engine_probe(struct platform_device *pdev)
spi_engine->offload_sdo_mem_size = SPI_ENGINE_OFFLOAD_SDO_FIFO_SIZE;
}
+ /* IP v1.5 dropped the requirement for SYNC in offload messages. */
+ spi_engine->offload_requires_sync = ADI_AXI_PCORE_VER_MINOR(version) < 5;
+
writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_RESET);
writel_relaxed(0xff, spi_engine->base + SPI_ENGINE_REG_INT_PENDING);
writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_INT_ENABLE);
generated by cgit (git 2.34.1) at 2025-05-29 17:30:51 +0000