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* [PATCH V2] spi: Update speed/mode on change
@ 2021-02-26 14:21 Marek Vasut
  2021-03-25 17:41 ` Marek Vasut
  2021-03-28 21:30 ` Tom Rini
  0 siblings, 2 replies; 31+ messages in thread
From: Marek Vasut @ 2021-02-26 14:21 UTC (permalink / raw)
  To: u-boot

The spi_get_bus_and_cs() may be called on the same bus and chipselect
with different frequency or mode. This is valid usecase, but the code
fails to notify the controller of such a configuration change. Call
spi_set_speed_mode() in case bus frequency or bus mode changed to let
the controller update the configuration.

The problem can easily be triggered using the sspi command:
=> sspi 0:0 at 1000
=> sspi 0:0 at 2000
Without this patch, both transfers happen at 1000 Hz. With this patch,
the later transfer happens correctly at 2000 Hz.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Jagan Teki <jagan@amarulasolutions.com>
Cc: Patrick Delaunay <patrick.delaunay@st.com>
---
V2: - Use bus_data->speed for the check
    - Release the bus on error
---
 drivers/spi/spi-uclass.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/spi/spi-uclass.c b/drivers/spi/spi-uclass.c
index 7155d4aebd6..5617f6645ee 100644
--- a/drivers/spi/spi-uclass.c
+++ b/drivers/spi/spi-uclass.c
@@ -405,12 +405,22 @@ int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
 			goto err;
 	}
 
+	/* In case bus frequency or mode changed, update it. */
+	if ((speed && bus_data->speed && bus_data->speed != speed) ||
+	    (plat->mode != mode)) {
+		ret = spi_set_speed_mode(bus, speed, mode);
+		if (ret)
+			goto err_speed_mode;
+	}
+
 	*busp = bus;
 	*devp = slave;
 	log_debug("%s: bus=%p, slave=%p\n", __func__, bus, *devp);
 
 	return 0;
 
+err_speed_mode:
+	spi_release_bus(slave);
 err:
 	log_debug("%s: Error path, created=%d, device '%s'\n", __func__,
 		  created, dev->name);
-- 
2.30.0

^ permalink raw reply related	[flat|nested] 31+ messages in thread
* [PATCH V2] spi: Update speed/mode on change
@ 2021-06-10 12:00 Marek Vasut
  2021-06-30 16:49 ` Tom Rini
  0 siblings, 1 reply; 31+ messages in thread
From: Marek Vasut @ 2021-06-10 12:00 UTC (permalink / raw)
  To: u-boot; +Cc: Marek Vasut, Jagan Teki, Patrick Delaunay

The spi_get_bus_and_cs() may be called on the same bus and chipselect
with different frequency or mode. This is valid usecase, but the code
fails to notify the controller of such a configuration change. Call
spi_set_speed_mode() in case bus frequency or bus mode changed to let
the controller update the configuration.

The problem can easily be triggered using the sspi command:
=> sspi 0:0@1000
=> sspi 0:0@2000
Without this patch, both transfers happen at 1000 Hz. With this patch,
the later transfer happens correctly at 2000 Hz.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Jagan Teki <jagan@amarulasolutions.com>
Cc: Patrick Delaunay <patrick.delaunay@foss.st.com>
---
V2: Set plat in case it is NULL
---
 drivers/spi/spi-uclass.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/spi/spi-uclass.c b/drivers/spi/spi-uclass.c
index ee30110b56..d867b27806 100644
--- a/drivers/spi/spi-uclass.c
+++ b/drivers/spi/spi-uclass.c
@@ -391,6 +391,8 @@ int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
 	} else if (ret) {
 		dev_err(bus, "Invalid chip select %d:%d (err=%d)\n", busnum, cs, ret);
 		return ret;
+	} else if (dev) {
+		plat = dev_get_parent_plat(dev);
 	}
 
 	if (!device_active(dev)) {
@@ -416,12 +418,22 @@ int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
 			goto err;
 	}
 
+	/* In case bus frequency or mode changed, update it. */
+	if ((speed && bus_data->speed && bus_data->speed != speed) ||
+	    (plat && plat->mode != mode)) {
+		ret = spi_set_speed_mode(bus, speed, mode);
+		if (ret)
+			goto err_speed_mode;
+	}
+
 	*busp = bus;
 	*devp = slave;
 	log_debug("%s: bus=%p, slave=%p\n", __func__, bus, *devp);
 
 	return 0;
 
+err_speed_mode:
+	spi_release_bus(slave);
 err:
 	log_debug("%s: Error path, created=%d, device '%s'\n", __func__,
 		  created, dev->name);
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 31+ messages in thread

end of thread, other threads:[~2021-07-02 20:20 UTC | newest]

Thread overview: 31+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-02-26 14:21 [PATCH V2] spi: Update speed/mode on change Marek Vasut
2021-03-25 17:41 ` Marek Vasut
2021-03-28 21:30 ` Tom Rini
2021-03-29  1:32   ` Marek Vasut
2021-03-29  1:59     ` Tom Rini
2021-03-29  2:09       ` Marek Vasut
2021-03-29  2:40         ` Marek Vasut
2021-03-31 19:18           ` Marek Vasut
2021-03-31 19:26             ` Tom Rini
2021-03-31 19:40               ` Tom Rini
2021-03-31 20:05                 ` Marek Vasut
2021-03-31 21:45                   ` Tom Rini
2021-03-31 22:19                     ` Simon Glass
2021-04-01 14:18                       ` Tom Rini
2021-03-31 22:39                     ` Marek Vasut
2021-03-31 22:50                       ` Simon Glass
2021-03-31 23:19                         ` Marek Vasut
2021-03-31 23:41                           ` Simon Glass
2021-03-31 23:47                             ` Marek Vasut
2021-03-31 23:54                               ` Tom Rini
2021-06-10 12:00 Marek Vasut
2021-06-30 16:49 ` Tom Rini
2021-07-02 17:24   ` Da Xue
2021-07-02 17:44     ` Marek Vasut
     [not found]       ` <CACdvmAh4MZ-rACRAY1nv1d0myCMyNnXjR5htkHTpe3A-wm=B1g@mail.gmail.com>
2021-07-02 18:10         ` Marek Vasut
2021-07-02 18:28           ` Da Xue
2021-07-02 19:06             ` Marek Vasut
2021-07-02 19:35               ` Da Xue
2021-07-02 19:40                 ` Marek Vasut
2021-07-02 20:10                   ` Da Xue
2021-07-02 20:20                     ` Marek Vasut

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