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-rw-r--r--drivers/spi/spi-axi-spi-engine.c116
1 files changed, 77 insertions, 39 deletions
diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c
index cbca783830ea..58280dd1c901 100644
--- a/drivers/spi/spi-axi-spi-engine.c
+++ b/drivers/spi/spi-axi-spi-engine.c
@@ -13,6 +13,7 @@
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/spi/spi.h>
+#include <linux/timer.h>
#define SPI_ENGINE_VERSION_MAJOR(x) ((x >> 16) & 0xff)
#define SPI_ENGINE_VERSION_MINOR(x) ((x >> 8) & 0xff)
@@ -114,6 +115,8 @@ struct spi_engine {
void __iomem *base;
struct ida sync_ida;
+ struct timer_list watchdog_timer;
+ struct spi_controller *controller;
unsigned int int_enable;
};
@@ -140,21 +143,6 @@ static unsigned int spi_engine_get_config(struct spi_device *spi)
return config;
}
-static unsigned int spi_engine_get_clk_div(struct spi_engine *spi_engine,
- struct spi_device *spi, struct spi_transfer *xfer)
-{
- unsigned int clk_div;
-
- clk_div = DIV_ROUND_UP(clk_get_rate(spi_engine->ref_clk),
- xfer->speed_hz * 2);
- if (clk_div > 255)
- clk_div = 255;
- else if (clk_div > 0)
- clk_div -= 1;
-
- return clk_div;
-}
-
static void spi_engine_gen_xfer(struct spi_engine_program *p, bool dry,
struct spi_transfer *xfer)
{
@@ -183,22 +171,16 @@ static void spi_engine_gen_xfer(struct spi_engine_program *p, bool dry,
}
static void spi_engine_gen_sleep(struct spi_engine_program *p, bool dry,
- struct spi_engine *spi_engine, unsigned int clk_div,
- struct spi_transfer *xfer)
+ int delay_ns, u32 sclk_hz)
{
- unsigned int spi_clk = clk_get_rate(spi_engine->ref_clk);
unsigned int t;
- int delay;
-
- delay = spi_delay_to_ns(&xfer->delay, xfer);
- if (delay < 0)
- return;
- delay /= 1000;
- if (delay == 0)
+ /* negative delay indicates error, e.g. from spi_delay_to_ns() */
+ if (delay_ns <= 0)
return;
- t = DIV_ROUND_UP(delay * spi_clk, (clk_div + 1) * 2);
+ /* rounding down since executing the instruction adds a couple of ticks delay */
+ t = DIV_ROUND_DOWN_ULL((u64)delay_ns * sclk_hz, NSEC_PER_SEC);
while (t) {
unsigned int n = min(t, 256U);
@@ -215,19 +197,41 @@ static void spi_engine_gen_cs(struct spi_engine_program *p, bool dry,
if (assert)
mask ^= BIT(spi_get_chipselect(spi, 0));
- spi_engine_program_add_cmd(p, dry, SPI_ENGINE_CMD_ASSERT(1, mask));
+ spi_engine_program_add_cmd(p, dry, SPI_ENGINE_CMD_ASSERT(0, mask));
}
-static int spi_engine_compile_message(struct spi_engine *spi_engine,
- struct spi_message *msg, bool dry, struct spi_engine_program *p)
+/*
+ * Performs precompile steps on the message.
+ *
+ * The SPI core does most of the message/transfer validation and filling in
+ * fields for us via __spi_validate(). This fixes up anything remaining not
+ * done there.
+ *
+ * NB: This is separate from spi_engine_compile_message() because the latter
+ * is called twice and would otherwise result in double-evaluation.
+ */
+static void spi_engine_precompile_message(struct spi_message *msg)
+{
+ unsigned int clk_div, max_hz = msg->spi->controller->max_speed_hz;
+ struct spi_transfer *xfer;
+
+ list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+ clk_div = DIV_ROUND_UP(max_hz, xfer->speed_hz);
+ xfer->effective_speed_hz = max_hz / min(clk_div, 256U);
+ }
+}
+
+static void spi_engine_compile_message(struct spi_message *msg, bool dry,
+ struct spi_engine_program *p)
{
struct spi_device *spi = msg->spi;
+ struct spi_controller *host = spi->controller;
struct spi_transfer *xfer;
int clk_div, new_clk_div;
bool keep_cs = false;
u8 bits_per_word = 0;
- clk_div = -1;
+ clk_div = 1;
spi_engine_program_add_cmd(p, dry,
SPI_ENGINE_CMD_WRITE(SPI_ENGINE_CMD_REG_CONFIG,
@@ -237,12 +241,13 @@ static int spi_engine_compile_message(struct spi_engine *spi_engine,
spi_engine_gen_cs(p, dry, spi, !xfer->cs_off);
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
- new_clk_div = spi_engine_get_clk_div(spi_engine, spi, xfer);
+ new_clk_div = host->max_speed_hz / xfer->effective_speed_hz;
if (new_clk_div != clk_div) {
clk_div = new_clk_div;
+ /* actual divider used is register value + 1 */
spi_engine_program_add_cmd(p, dry,
SPI_ENGINE_CMD_WRITE(SPI_ENGINE_CMD_REG_CLK_DIV,
- clk_div));
+ clk_div - 1));
}
if (bits_per_word != xfer->bits_per_word) {
@@ -253,7 +258,8 @@ static int spi_engine_compile_message(struct spi_engine *spi_engine,
}
spi_engine_gen_xfer(p, dry, xfer);
- spi_engine_gen_sleep(p, dry, spi_engine, clk_div, xfer);
+ spi_engine_gen_sleep(p, dry, spi_delay_to_ns(&xfer->delay, xfer),
+ xfer->effective_speed_hz);
if (xfer->cs_change) {
if (list_is_last(&xfer->transfer_list, &msg->transfers)) {
@@ -262,6 +268,10 @@ static int spi_engine_compile_message(struct spi_engine *spi_engine,
if (!xfer->cs_off)
spi_engine_gen_cs(p, dry, spi, false);
+ spi_engine_gen_sleep(p, dry, spi_delay_to_ns(
+ &xfer->cs_change_delay, xfer),
+ xfer->effective_speed_hz);
+
if (!list_next_entry(xfer, transfer_list)->cs_off)
spi_engine_gen_cs(p, dry, spi, true);
}
@@ -274,7 +284,13 @@ static int spi_engine_compile_message(struct spi_engine *spi_engine,
if (!keep_cs)
spi_engine_gen_cs(p, dry, spi, false);
- return 0;
+ /*
+ * Restore clockdiv to default so that future gen_sleep commands don't
+ * have to be aware of the current register state.
+ */
+ if (clk_div != 1)
+ spi_engine_program_add_cmd(p, dry,
+ SPI_ENGINE_CMD_WRITE(SPI_ENGINE_CMD_REG_CLK_DIV, 0));
}
static void spi_engine_xfer_next(struct spi_message *msg,
@@ -475,9 +491,11 @@ static irqreturn_t spi_engine_irq(int irq, void *devid)
struct spi_engine_message_state *st = msg->state;
if (completed_id == st->sync_id) {
- msg->status = 0;
- msg->actual_length = msg->frame_length;
- spi_finalize_current_message(host);
+ if (timer_delete_sync(&spi_engine->watchdog_timer)) {
+ msg->status = 0;
+ msg->actual_length = msg->frame_length;
+ spi_finalize_current_message(host);
+ }
disable_int |= SPI_ENGINE_INT_SYNC;
}
}
@@ -506,8 +524,10 @@ static int spi_engine_prepare_message(struct spi_controller *host,
if (!st)
return -ENOMEM;
+ spi_engine_precompile_message(msg);
+
p_dry.length = 0;
- spi_engine_compile_message(spi_engine, msg, true, &p_dry);
+ spi_engine_compile_message(msg, true, &p_dry);
size = sizeof(*p->instructions) * (p_dry.length + 1);
p = kzalloc(sizeof(*p) + size, GFP_KERNEL);
@@ -525,7 +545,7 @@ static int spi_engine_prepare_message(struct spi_controller *host,
st->sync_id = ret;
- spi_engine_compile_message(spi_engine, msg, false, p);
+ spi_engine_compile_message(msg, false, p);
spi_engine_program_add_cmd(p, false, SPI_ENGINE_CMD_SYNC(st->sync_id));
@@ -558,6 +578,8 @@ static int spi_engine_transfer_one_message(struct spi_controller *host,
unsigned int int_enable = 0;
unsigned long flags;
+ mod_timer(&spi_engine->watchdog_timer, jiffies + msecs_to_jiffies(5000));
+
spin_lock_irqsave(&spi_engine->lock, flags);
if (spi_engine_write_cmd_fifo(spi_engine, msg))
@@ -581,6 +603,20 @@ static int spi_engine_transfer_one_message(struct spi_controller *host,
return 0;
}
+static void spi_engine_timeout(struct timer_list *timer)
+{
+ struct spi_engine *spi_engine = from_timer(spi_engine, timer, watchdog_timer);
+ struct spi_controller *host = spi_engine->controller;
+
+ if (WARN_ON(!host->cur_msg))
+ return;
+
+ dev_err(&host->dev,
+ "Timeout occurred while waiting for transfer to complete. Hardware is probably broken.\n");
+ host->cur_msg->status = -ETIMEDOUT;
+ spi_finalize_current_message(host);
+}
+
static void spi_engine_release_hw(void *p)
{
struct spi_engine *spi_engine = p;
@@ -610,6 +646,8 @@ static int spi_engine_probe(struct platform_device *pdev)
spin_lock_init(&spi_engine->lock);
ida_init(&spi_engine->sync_ida);
+ timer_setup(&spi_engine->watchdog_timer, spi_engine_timeout, TIMER_IRQSAFE);
+ spi_engine->controller = host;
spi_engine->clk = devm_clk_get_enabled(&pdev->dev, "s_axi_aclk");
if (IS_ERR(spi_engine->clk))
generated by cgit v1.2.3 (git 2.39.0) at 2025-03-03 04:01:57 +0300