[PATCH 0/9] spi: axi-spi-engine: improvements round 2

[PATCH 0/9] spi: axi-spi-engine: improvements round 2

[David Lechner]

We are working towards adding support for the offload feature [1] of the
AXI SPI Engine IP core. Before we can do that, we want to make some
general fixes and improvements to the driver. In order to avoid a giant
series with 35+ patches, we are splitting this up into a few smaller
series.

This is a continuation of the work started in [2] which has been applied
to spi/for-6.8 [3]. This series must be applied on top of that series to
apply cleanly.

Once this series is applied, we will follow up with the 3rd series that
implements the offload support. The offload support will also involve
the IIO subsystem (a new IIO driver will depend on the new SPI offload
feature), so I'm mentioning this now in case we want to do anything
ahead of time to prepare for that (e.g. putting all of these changes on
a separate branch).

[1]: https://wiki.analog.com/resources/fpga/peripherals/spi_engine/offload
[2]: https://lore.kernel.org/linux-spi/20231117-axi-spi-engine-series-1-v1-0-cc59db999b87@baylibre.com/
[3]: https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git/log/?h=for-6.8

---
David Lechner (9):
      spi: axi-spi-engine: return void from spi_engine_compile_message()
      spi: axi-spi-engine: populate xfer->effective_speed_hz
      spi: axi-spi-engine: remove spi_engine_get_clk_div()
      spi: axi-spi-engine: fix sleep ticks calculation
      spi: axi-spi-engine: remove xfer arg from spi_engine_gen_sleep()
      spi: axi-spi-engine: implement xfer->cs_change_delay
      spi: axi-spi-engine: restore clkdiv at end of message
      spi: axi-spi-engine: remove delay from CS assertion
      spi: axi-spi-engine: add watchdog timer

 drivers/spi/spi-axi-spi-engine.c | 116 ++++++++++++++++++++++++++-------------
 1 file changed, 77 insertions(+), 39 deletions(-)
---
base-commit: 8e6a43961f24cf841d3c0d199521d0b284d948b9
change-id: 20231129-axi-spi-engine-series-2-5f0a6053dea0

[PATCH 1/9] spi: axi-spi-engine: return void from spi_engine_compile_message()

[David Lechner]

In the AXI SPI Engine driver, the spi_engine_compile_message() function
does not return any error and none of the callers check the return
value. So we can change the return type to void and drop the return 0.

Signed-off-by: David Lechner <dlechner@baylibre.com>
---
 drivers/spi/spi-axi-spi-engine.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c
index cbca783830ea..982b37ac3063 100644
--- a/drivers/spi/spi-axi-spi-engine.c
+++ b/drivers/spi/spi-axi-spi-engine.c
@@ -218,7 +218,7 @@ static void spi_engine_gen_cs(struct spi_engine_program *p, bool dry,
 	spi_engine_program_add_cmd(p, dry, SPI_ENGINE_CMD_ASSERT(1, mask));
 }
 
-static int spi_engine_compile_message(struct spi_engine *spi_engine,
+static void spi_engine_compile_message(struct spi_engine *spi_engine,
 	struct spi_message *msg, bool dry, struct spi_engine_program *p)
 {
 	struct spi_device *spi = msg->spi;
@@ -273,8 +273,6 @@ static int spi_engine_compile_message(struct spi_engine *spi_engine,
 
 	if (!keep_cs)
 		spi_engine_gen_cs(p, dry, spi, false);
-
-	return 0;
 }
 
 static void spi_engine_xfer_next(struct spi_message *msg,

-- 
2.43.0

[PATCH 2/9] spi: axi-spi-engine: populate xfer->effective_speed_hz

[David Lechner]

This adds a new spi_engine_precompile_message() function to the ADI AXI
SPI Engine driver to populate the xfer->effective_speed_hz field since
the SPI core doesn't/can't do this for us.

This driver is already using spi_delay_to_ns() which depends on
effective_speed_hz to get an accurate value in some cases.
Having an effective_speed_hz value can also be used in future changes
to simplify other code.

Signed-off-by: David Lechner <dlechner@baylibre.com>
---
 drivers/spi/spi-axi-spi-engine.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c
index 982b37ac3063..ee7b904ae5cf 100644
--- a/drivers/spi/spi-axi-spi-engine.c
+++ b/drivers/spi/spi-axi-spi-engine.c
@@ -218,6 +218,27 @@ static void spi_engine_gen_cs(struct spi_engine_program *p, bool dry,
 	spi_engine_program_add_cmd(p, dry, SPI_ENGINE_CMD_ASSERT(1, mask));
 }
 
+/*
+ * 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_engine *spi_engine,
 	struct spi_message *msg, bool dry, struct spi_engine_program *p)
 {
@@ -504,6 +525,8 @@ 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);
 

-- 
2.43.0

[PATCH 3/9] spi: axi-spi-engine: remove spi_engine_get_clk_div()

[David Lechner]

Now that host->max_speed_hz and xfer->effective_speed_hz are properly
set, we can use them instead of having to do more complex calculations
to get the clock divider for each transfer.

This removes the spi_engine_get_clk_div() function and replaces it with
just dividing the two clock rates. Since the hardware register value is
the divider minus one, we need to subtract one. Subtracting one was
previously done in the spi_engine_get_clk_div() function.

Signed-off-by: David Lechner <dlechner@baylibre.com>
---
 drivers/spi/spi-axi-spi-engine.c | 23 +++++------------------
 1 file changed, 5 insertions(+), 18 deletions(-)

diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c
index ee7b904ae5cf..fa2264d630c3 100644
--- a/drivers/spi/spi-axi-spi-engine.c
+++ b/drivers/spi/spi-axi-spi-engine.c
@@ -140,21 +140,6 @@ 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)
 {
@@ -243,6 +228,7 @@ static void spi_engine_compile_message(struct spi_engine *spi_engine,
 	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;
@@ -258,12 +244,13 @@ static void 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) {
@@ -274,7 +261,7 @@ static void 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_engine, clk_div - 1, xfer);
 
 		if (xfer->cs_change) {
 			if (list_is_last(&xfer->transfer_list, &msg->transfers)) {

-- 
2.43.0

[PATCH 4/9] spi: axi-spi-engine: fix sleep ticks calculation

[David Lechner]

This fixes the sleep ticks calculation when generating sleep
instructions in the AXI SPI Engine driver. The previous calculation
was ignoring delays less than one microsecond and missed a microsecond
to second conversion factor.

This fixes the first issue by not rounding to microseconds. Now that
xfer->effective_speed_hz is guaranteed to be set correctly, we can use
that to simplify the calculation. This new calculation replaces the old
incorrect math.

Also add unit suffix to the delay variable for clarity while we are
touching this.

Signed-off-by: David Lechner <dlechner@baylibre.com>
---
 drivers/spi/spi-axi-spi-engine.c | 25 ++++++++++---------------
 1 file changed, 10 insertions(+), 15 deletions(-)

diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c
index fa2264d630c3..b3e72308fcc5 100644
--- a/drivers/spi/spi-axi-spi-engine.c
+++ b/drivers/spi/spi-axi-spi-engine.c
@@ -168,22 +168,17 @@ 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)
 {
-	unsigned int spi_clk = clk_get_rate(spi_engine->ref_clk);
 	unsigned int t;
-	int delay;
+	int delay_ns;
 
-	delay = spi_delay_to_ns(&xfer->delay, xfer);
-	if (delay < 0)
+	delay_ns = spi_delay_to_ns(&xfer->delay, xfer);
+	if (delay_ns <= 0)
 		return;
-	delay /= 1000;
 
-	if (delay == 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 * xfer->effective_speed_hz, NSEC_PER_SEC);
 	while (t) {
 		unsigned int n = min(t, 256U);
 
@@ -224,8 +219,8 @@ static void spi_engine_precompile_message(struct spi_message *msg)
 	}
 }
 
-static void spi_engine_compile_message(struct spi_engine *spi_engine,
-	struct spi_message *msg, bool dry, struct spi_engine_program *p)
+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;
@@ -261,7 +256,7 @@ static void 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 - 1, xfer);
+		spi_engine_gen_sleep(p, dry, xfer);
 
 		if (xfer->cs_change) {
 			if (list_is_last(&xfer->transfer_list, &msg->transfers)) {
@@ -515,7 +510,7 @@ static int spi_engine_prepare_message(struct spi_controller *host,
 	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);
@@ -533,7 +528,7 @@ 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));
 

-- 
2.43.0

[PATCH 5/9] spi: axi-spi-engine: remove xfer arg from spi_engine_gen_sleep()

[David Lechner]

This replaces the xfer parameter of spi_engine_gen_sleep() in the AXI
SPI Engine driver with parameters for the delay in nanoseconds and the
SPI SCLK rate. This will allow this function to be used by callers in
the future that do not have a spi_transfer struct.

Signed-off-by: David Lechner <dlechner@baylibre.com>
---
 drivers/spi/spi-axi-spi-engine.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c
index b3e72308fcc5..84ec37732d8b 100644
--- a/drivers/spi/spi-axi-spi-engine.c
+++ b/drivers/spi/spi-axi-spi-engine.c
@@ -168,17 +168,16 @@ 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_transfer *xfer)
+				 int delay_ns, u32 sclk_hz)
 {
 	unsigned int t;
-	int delay_ns;
 
-	delay_ns = spi_delay_to_ns(&xfer->delay, xfer);
+	/* negative delay indicates error, e.g. from spi_delay_to_ns() */
 	if (delay_ns <= 0)
 		return;
 
 	/* rounding down since executing the instruction adds a couple of ticks delay */
-	t = DIV_ROUND_DOWN_ULL((u64)delay_ns * xfer->effective_speed_hz, NSEC_PER_SEC);
+	t = DIV_ROUND_DOWN_ULL((u64)delay_ns * sclk_hz, NSEC_PER_SEC);
 	while (t) {
 		unsigned int n = min(t, 256U);
 
@@ -256,7 +255,8 @@ static void spi_engine_compile_message(struct spi_message *msg, bool dry,
 		}
 
 		spi_engine_gen_xfer(p, dry, xfer);
-		spi_engine_gen_sleep(p, dry, 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)) {

-- 
2.43.0

[PATCH 6/9] spi: axi-spi-engine: implement xfer->cs_change_delay

[David Lechner]

This adds handling of xfer->cs_change_delay to the AXI SPI Engine
driver.

Signed-off-by: David Lechner <dlechner@baylibre.com>
---
 drivers/spi/spi-axi-spi-engine.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c
index 84ec37732d8b..3437829ef8b1 100644
--- a/drivers/spi/spi-axi-spi-engine.c
+++ b/drivers/spi/spi-axi-spi-engine.c
@@ -265,6 +265,10 @@ static void spi_engine_compile_message(struct spi_message *msg, bool dry,
 				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);
 			}

-- 
2.43.0

[PATCH 7/9] spi: axi-spi-engine: restore clkdiv at end of message

[David Lechner]

This modifies the ADI AXI SPI Engine driver to restore the clkdiv
configuration register at the end of a SPI message. Having the clkdiv in
a known state is needed to be able to add a new command in the future
that only performs a delay without any SPI transfers. Furthermore having
that state be the smallest possible divider will allow these delays to
have the highest possible precision.

Changing the initial value of clk_div from -1 to 1 is now possible
because we know the function will always be called with a known clkdiv
config register state. Making this change will also have the effect of
not emitting a clkdiv configuration register instruction in cases where
the maximum sclk rate is used. Having one less instruction to process
reduces delays on the bus which will be beneficial when we implement
offload support to enable reading data from devices at very high rates.

Signed-off-by: David Lechner <dlechner@baylibre.com>
---
 drivers/spi/spi-axi-spi-engine.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c
index 3437829ef8b1..3798f96da586 100644
--- a/drivers/spi/spi-axi-spi-engine.c
+++ b/drivers/spi/spi-axi-spi-engine.c
@@ -228,7 +228,7 @@ static void spi_engine_compile_message(struct spi_message *msg, bool dry,
 	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,
@@ -280,6 +280,14 @@ static void spi_engine_compile_message(struct spi_message *msg, bool dry,
 
 	if (!keep_cs)
 		spi_engine_gen_cs(p, dry, spi, false);
+
+	/*
+	 * 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,

-- 
2.43.0

[PATCH 8/9] spi: axi-spi-engine: remove delay from CS assertion

[David Lechner]

Now that the AXI SPI Engine driver has support for the various CS delays
requested through struct spi_message, we don't need to add a separate
delay to the CS assertion instruction. Otherwise, we end up with longer
than requested delays.

Signed-off-by: David Lechner <dlechner@baylibre.com>
---
 drivers/spi/spi-axi-spi-engine.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c
index 3798f96da586..78221715ba81 100644
--- a/drivers/spi/spi-axi-spi-engine.c
+++ b/drivers/spi/spi-axi-spi-engine.c
@@ -194,7 +194,7 @@ 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));
 }
 
 /*

-- 
2.43.0

[PATCH 9/9] spi: axi-spi-engine: add watchdog timer

[David Lechner]

If there is an issue with the AXI SPI Engine hardware a scheduled
transfer might never be completed and spi_sync() will block forever.
This due to the uninterruptible wait for completion waiting for the
spi_finalize_current_message() that never comes.

Add a watchdog timer that will abort a transfer 5 seconds after it has
been started. This will potentially leave the hardware in a broken state
but it allows software to recover and allow to better diagnose the
underlying issue.

Co-developed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: David Lechner <dlechner@baylibre.com>
---
 drivers/spi/spi-axi-spi-engine.c | 29 ++++++++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c
index 78221715ba81..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;
 };
@@ -488,9 +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;
 		}
 	}
@@ -573,6 +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))
@@ -596,6 +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;
@@ -625,6 +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))

-- 
2.43.0

Re: [PATCH 0/9] spi: axi-spi-engine: improvements round 2

[Nuno Sá]

On Mon, 2023-12-04 at 11:33 -0600, David Lechner wrote:
> We are working towards adding support for the offload feature [1] of the
> AXI SPI Engine IP core. Before we can do that, we want to make some
> general fixes and improvements to the driver. In order to avoid a giant
> series with 35+ patches, we are splitting this up into a few smaller
> series.
> 
> This is a continuation of the work started in [2] which has been applied
> to spi/for-6.8 [3]. This series must be applied on top of that series to
> apply cleanly.
> 
> Once this series is applied, we will follow up with the 3rd series that
> implements the offload support. The offload support will also involve
> the IIO subsystem (a new IIO driver will depend on the new SPI offload
> feature), so I'm mentioning this now in case we want to do anything
> ahead of time to prepare for that (e.g. putting all of these changes on
> a separate branch).
> 
> [1]: https://wiki.analog.com/resources/fpga/peripherals/spi_engine/offload
> [2]:
> https://lore.kernel.org/linux-spi/20231117-axi-spi-engine-series-1-v1-0-cc59db999b87@baylibre.com/
> [3]: https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git/log/?h=for-6.8
> 
> ---

Acked-by: Nuno Sa <nuno.sa@analog.com>

> David Lechner (9):
>       spi: axi-spi-engine: return void from spi_engine_compile_message()
>       spi: axi-spi-engine: populate xfer->effective_speed_hz
>       spi: axi-spi-engine: remove spi_engine_get_clk_div()
>       spi: axi-spi-engine: fix sleep ticks calculation
>       spi: axi-spi-engine: remove xfer arg from spi_engine_gen_sleep()
>       spi: axi-spi-engine: implement xfer->cs_change_delay
>       spi: axi-spi-engine: restore clkdiv at end of message
>       spi: axi-spi-engine: remove delay from CS assertion
>       spi: axi-spi-engine: add watchdog timer
> 
>  drivers/spi/spi-axi-spi-engine.c | 116 ++++++++++++++++++++++++++-------------
>  1 file changed, 77 insertions(+), 39 deletions(-)
> ---
> base-commit: 8e6a43961f24cf841d3c0d199521d0b284d948b9
> change-id: 20231129-axi-spi-engine-series-2-5f0a6053dea0

RE: [PATCH 0/9] spi: axi-spi-engine: improvements round 2

[Hennerich, Michael]

> -----Original Message-----
> From: Nuno Sá <noname.nuno@gmail.com>
> Sent: Dienstag, 5. Dezember 2023 16:12
> To: David Lechner <dlechner@baylibre.com>; linux-spi@vger.kernel.org
> Cc: Mark Brown <broonie@kernel.org>; Hennerich, Michael
> <Michael.Hennerich@analog.com>; Sa, Nuno <Nuno.Sa@analog.com>; linux-
> kernel@vger.kernel.org; Lars-Peter Clausen <lars@metafoo.de>
> Subject: Re: [PATCH 0/9] spi: axi-spi-engine: improvements round 2
> 
> 
> On Mon, 2023-12-04 at 11:33 -0600, David Lechner wrote:
> > We are working towards adding support for the offload feature [1] of
> > the AXI SPI Engine IP core. Before we can do that, we want to make
> > some general fixes and improvements to the driver. In order to avoid a
> > giant series with 35+ patches, we are splitting this up into a few
> > smaller series.
> >
> > This is a continuation of the work started in [2] which has been
> > applied to spi/for-6.8 [3]. This series must be applied on top of that
> > series to apply cleanly.
> >
> > Once this series is applied, we will follow up with the 3rd series
> > that implements the offload support. The offload support will also
> > involve the IIO subsystem (a new IIO driver will depend on the new SPI
> > offload feature), so I'm mentioning this now in case we want to do
> > anything ahead of time to prepare for that (e.g. putting all of these
> > changes on a separate branch).
> >
> > [1]:
> > https://wiki.analog.com/resources/fpga/peripherals/spi_engine/offload
> > [2]:
> > https://urldefense.com/v3/__https://lore.kernel.org/linux-spi/20231117
> > -axi-spi-engine-series-1-v1-0-cc59db999b87@baylibre.com/__;!!A3Ni8CS0y
> >
> 2Y!4P8x0PlUachyveotKnjDl76l9lcBm5HvGgZVXAfsa26fHvTXZ7Cvmq2lt_ZPP58
> nPhJ
> > K_sGO56g48deUWlcDSsY8qg$
> > [3]:
> > https://urldefense.com/v3/__https://git.kernel.org/pub/scm/linux/kerne
> > l/git/broonie/spi.git/log/?h=for-6.8__;!!A3Ni8CS0y2Y!4P8x0PlUachyveotK
> >
> njDl76l9lcBm5HvGgZVXAfsa26fHvTXZ7Cvmq2lt_ZPP58nPhJK_sGO56g48deU
> Wlfwzsn
> > PJw$
> >
> > ---
> 
> Acked-by: Nuno Sa <nuno.sa@analog.com>
Acked-by: Michael Hennerich <michael.hennerich@analog.com>

> 
> > David Lechner (9):
> >       spi: axi-spi-engine: return void from
> > spi_engine_compile_message()
> >       spi: axi-spi-engine: populate xfer->effective_speed_hz
> >       spi: axi-spi-engine: remove spi_engine_get_clk_div()
> >       spi: axi-spi-engine: fix sleep ticks calculation
> >       spi: axi-spi-engine: remove xfer arg from spi_engine_gen_sleep()
> >       spi: axi-spi-engine: implement xfer->cs_change_delay
> >       spi: axi-spi-engine: restore clkdiv at end of message
> >       spi: axi-spi-engine: remove delay from CS assertion
> >       spi: axi-spi-engine: add watchdog timer
> >
> >  drivers/spi/spi-axi-spi-engine.c | 116
> > ++++++++++++++++++++++++++-------------
> >  1 file changed, 77 insertions(+), 39 deletions(-)
> > ---
> > base-commit: 8e6a43961f24cf841d3c0d199521d0b284d948b9
> > change-id: 20231129-axi-spi-engine-series-2-5f0a6053dea0

Re: [PATCH 0/9] spi: axi-spi-engine: improvements round 2

[Mark Brown]

On Mon, 04 Dec 2023 11:33:26 -0600, David Lechner wrote:
> We are working towards adding support for the offload feature [1] of the
> AXI SPI Engine IP core. Before we can do that, we want to make some
> general fixes and improvements to the driver. In order to avoid a giant
> series with 35+ patches, we are splitting this up into a few smaller
> series.
> 
> This is a continuation of the work started in [2] which has been applied
> to spi/for-6.8 [3]. This series must be applied on top of that series to
> apply cleanly.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/9] spi: axi-spi-engine: return void from spi_engine_compile_message()
      commit: 2e0d75f8dd9e31b3fb175f780494dd7dd988ceae
[2/9] spi: axi-spi-engine: populate xfer->effective_speed_hz
      commit: 9d023ecc31859c7f7c8ca27b5fec52b2dbb8086f
[3/9] spi: axi-spi-engine: remove spi_engine_get_clk_div()
      commit: 1fc8dc5721bbc7a21cb4cc60c35eb8031942542b
[4/9] spi: axi-spi-engine: fix sleep ticks calculation
      commit: be9070bcf67057b7b03c5acc1980d3897448ad20
[5/9] spi: axi-spi-engine: remove xfer arg from spi_engine_gen_sleep()
      commit: e006c181dd9ab006d7b0982d35ef7951fbffe825
[6/9] spi: axi-spi-engine: implement xfer->cs_change_delay
      commit: 125a8390995df1a350e9e16e6da11d010e1e7f76
[7/9] spi: axi-spi-engine: restore clkdiv at end of message
      commit: 3106edac599f59e1298b034a19a43e7da002fccc
[8/9] spi: axi-spi-engine: remove delay from CS assertion
      commit: 0db60d821e485a1c9b8080dbec1ba9871efb6a65
[9/9] spi: axi-spi-engine: add watchdog timer
      commit: 07d33c2810bb5fe67747d11f76980ed68602e287

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark