[PATCH v2] spi: Add spi_get_bus_and_cs() new use_dt param

Patrice Chotard patrice.chotard at foss.st.com
Mon Feb 21 08:33:49 CET 2022


Add spi_get_bus_and_cs() new "use_dt" param which allows to
select SPI speed and mode from DT or from default value passed
in parameters.

Introduce spi_flash_probe_bus_cs_default() which is identical
to spi_flash_probe_bus_cs() except it calls spi_get_bus_and_cs()
with use_dt param set to false.

Since commit e2e95e5e2542 ("spi: Update speed/mode on change")
when calling "sf probe" or "env save" on SPI flash,
spi_set_speed_mode() is called twice.

spi_get_bus_and_cs()
      |--> spi_claim_bus()
      |       |--> spi_set_speed_mode(speed and mode from DT)
      ...
      |--> spi_set_speed_mode(default speed and mode value)

The first spi_set_speed_mode() call is done with speed and mode
values from DT, whereas the second call is done with speed
and mode set to default value (speed is set to CONFIG_SF_DEFAULT_SPEED)

This is an issue because SPI flash performance are impacted by
using default speed which can be lower than the one defined in DT.

One solution is to set CONFIG_SF_DEFAULT_SPEED to the speed defined
in DT, but we loose flexibility offered by DT.

Another issue can be encountered with 2 SPI flashes using 2 different
speeds. In this specific case usage of CONFIG_SF_DEFAULT_SPEED is not
flexible compared to get the 2 different speeds from DT.

By adding new parameter "use_dt" to spi_get_bus_and_cs(), this allows
to force usage of either speed and mode from DT (use_dt = true) or to
use speed and mode parameter value.

Signed-off-by: Patrice Chotard <patrice.chotard at foss.st.com>
Cc: Marek Behun <marek.behun at nic.cz>
Cc: Jagan Teki <jagan at amarulasolutions.com>
Cc: Vignesh R <vigneshr at ti.com>
Cc: Joe Hershberger <joe.hershberger at ni.com>
Cc: Ramon Fried <rfried.dev at gmail.com>
Cc: Lukasz Majewski <lukma at denx.de>
Cc: Marek Vasut <marex at denx.de>
Cc: Wolfgang Denk <wd at denx.de>
Cc: Simon Glass <sjg at chromium.org>
Cc: Stefan Roese <sr at denx.de>
Cc: "Pali Rohár" <pali at kernel.org>
Cc: Konstantin Porotchkin <kostap at marvell.com>
Cc: Igal Liberman <igall at marvell.com>
Cc: Bin Meng <bmeng.cn at gmail.com>
Cc: Pratyush Yadav <p.yadav at ti.com>
Cc: Sean Anderson <seanga2 at gmail.com>
Cc: Anji J <anji.jagarlmudi at nxp.com>
Cc: Biwen Li <biwen.li at nxp.com>
Cc: Priyanka Jain <priyanka.jain at nxp.com>
Cc: Chaitanya Sakinam <chaitanya.sakinam at nxp.com>

---

Changes in v2:
  - add spi_flash_probe_bus_cs_default() which calls spi_get_bus_and_cs()
    with "use_dt" param set to true, whereas spi_flash_probe_bus_cs() calls
    spi_get_bus_and_cs() with "use_dt" param set to true.

 board/CZ.NIC/turris_mox/turris_mox.c |  2 +-
 cmd/sf.c                             |  9 ++++++++-
 cmd/spi.c                            |  2 +-
 drivers/mtd/spi/sf-uclass.c          | 30 ++++++++++++++++++++++++++--
 drivers/spi/spi-uclass.c             |  8 ++++----
 drivers/usb/gadget/max3420_udc.c     |  2 +-
 include/spi.h                        |  7 ++++---
 include/spi_flash.h                  |  4 ++++
 test/dm/spi.c                        | 15 +++++++-------
 9 files changed, 59 insertions(+), 20 deletions(-)

diff --git a/board/CZ.NIC/turris_mox/turris_mox.c b/board/CZ.NIC/turris_mox/turris_mox.c
index f0c5aa6a52..4b755e1420 100644
--- a/board/CZ.NIC/turris_mox/turris_mox.c
+++ b/board/CZ.NIC/turris_mox/turris_mox.c
@@ -148,7 +148,7 @@ static int mox_do_spi(u8 *in, u8 *out, size_t size)
 	struct udevice *dev;
 	int ret;
 
-	ret = spi_get_bus_and_cs(0, 1, 1000000, SPI_CPHA | SPI_CPOL,
+	ret = spi_get_bus_and_cs(0, 1, 1000000, SPI_CPHA | SPI_CPOL, false,
 				 "spi_generic_drv", "moxtet at 1", &dev,
 				 &slave);
 	if (ret)
diff --git a/cmd/sf.c b/cmd/sf.c
index 8bdebd9fd8..40b2cc3297 100644
--- a/cmd/sf.c
+++ b/cmd/sf.c
@@ -91,6 +91,7 @@ static int do_spi_flash_probe(int argc, char *const argv[])
 	unsigned int speed = CONFIG_SF_DEFAULT_SPEED;
 	unsigned int mode = CONFIG_SF_DEFAULT_MODE;
 	char *endp;
+	bool use_dt = true;
 #if CONFIG_IS_ENABLED(DM_SPI_FLASH)
 	struct udevice *new, *bus_dev;
 	int ret;
@@ -117,11 +118,13 @@ static int do_spi_flash_probe(int argc, char *const argv[])
 		speed = simple_strtoul(argv[2], &endp, 0);
 		if (*argv[2] == 0 || *endp != 0)
 			return -1;
+		use_dt = false;
 	}
 	if (argc >= 4) {
 		mode = hextoul(argv[3], &endp);
 		if (*argv[3] == 0 || *endp != 0)
 			return -1;
+		use_dt = false;
 	}
 
 #if CONFIG_IS_ENABLED(DM_SPI_FLASH)
@@ -131,7 +134,11 @@ static int do_spi_flash_probe(int argc, char *const argv[])
 		device_remove(new, DM_REMOVE_NORMAL);
 	}
 	flash = NULL;
-	ret = spi_flash_probe_bus_cs(bus, cs, speed, mode, &new);
+	if (use_dt)
+		ret = spi_flash_probe_bus_cs(bus, cs, speed, mode, &new);
+	else
+		ret = spi_flash_probe_bus_cs_default(bus, cs, speed, mode, &new);
+
 	if (ret) {
 		printf("Failed to initialize SPI flash at %u:%u (error %d)\n",
 		       bus, cs, ret);
diff --git a/cmd/spi.c b/cmd/spi.c
index 6dc32678da..46bd817e60 100644
--- a/cmd/spi.c
+++ b/cmd/spi.c
@@ -46,7 +46,7 @@ static int do_spi_xfer(int bus, int cs)
 	str = strdup(name);
 	if (!str)
 		return -ENOMEM;
-	ret = spi_get_bus_and_cs(bus, cs, freq, mode, "spi_generic_drv",
+	ret = spi_get_bus_and_cs(bus, cs, freq, mode, false, "spi_generic_drv",
 				 str, &dev, &slave);
 	if (ret)
 		return ret;
diff --git a/drivers/mtd/spi/sf-uclass.c b/drivers/mtd/spi/sf-uclass.c
index 63d16291ff..f38518b7fd 100644
--- a/drivers/mtd/spi/sf-uclass.c
+++ b/drivers/mtd/spi/sf-uclass.c
@@ -74,8 +74,34 @@ int spi_flash_probe_bus_cs(unsigned int busnum, unsigned int cs,
 	snprintf(name, sizeof(name), "spi_flash@%d:%d", busnum, cs);
 	str = strdup(name);
 #endif
-	ret = spi_get_bus_and_cs(busnum, cs, max_hz, spi_mode,
-				  "jedec_spi_nor", str, &bus, &slave);
+	ret = spi_get_bus_and_cs(busnum, cs, max_hz, spi_mode, true,
+				 "jedec_spi_nor", str, &bus, &slave);
+	if (ret)
+		return ret;
+
+	*devp = slave->dev;
+	return 0;
+}
+
+int spi_flash_probe_bus_cs_default(unsigned int busnum, unsigned int cs,
+				   unsigned int max_hz, unsigned int spi_mode,
+				   struct udevice **devp)
+{
+	struct spi_slave *slave;
+	struct udevice *bus;
+	char *str;
+	int ret;
+
+#if defined(CONFIG_SPL_BUILD) && CONFIG_IS_ENABLED(USE_TINY_PRINTF)
+	str = "spi_flash";
+#else
+	char name[30];
+
+	snprintf(name, sizeof(name), "spi_flash@%d:%d", busnum, cs);
+	str = strdup(name);
+#endif
+	ret = spi_get_bus_and_cs(busnum, cs, max_hz, spi_mode, false,
+				 "jedec_spi_nor", str, &bus, &slave);
 	if (ret)
 		return ret;
 
diff --git a/drivers/spi/spi-uclass.c b/drivers/spi/spi-uclass.c
index f8ec312d71..4366124e3c 100644
--- a/drivers/spi/spi-uclass.c
+++ b/drivers/spi/spi-uclass.c
@@ -340,7 +340,7 @@ int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp,
 	return ret;
 }
 
-int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
+int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode, bool use_dt,
 		       const char *drv_name, const char *dev_name,
 		       struct udevice **busp, struct spi_slave **devp)
 {
@@ -419,8 +419,8 @@ int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
 	}
 
 	/* In case bus frequency or mode changed, update it. */
-	if ((speed && bus_data->speed && bus_data->speed != speed) ||
-	    (plat && plat->mode != mode)) {
+	if (((speed && bus_data->speed && bus_data->speed != speed) ||
+	     (plat && plat->mode != mode)) && !use_dt) {
 		ret = spi_set_speed_mode(bus, speed, mode);
 		if (ret)
 			goto err_speed_mode;
@@ -453,7 +453,7 @@ struct spi_slave *spi_setup_slave(unsigned int busnum, unsigned int cs,
 	struct udevice *dev;
 	int ret;
 
-	ret = spi_get_bus_and_cs(busnum, cs, speed, mode, NULL, 0, &dev,
+	ret = spi_get_bus_and_cs(busnum, cs, speed, mode, false, NULL, 0, &dev,
 				 &slave);
 	if (ret)
 		return NULL;
diff --git a/drivers/usb/gadget/max3420_udc.c b/drivers/usb/gadget/max3420_udc.c
index a16095f892..ccec337f99 100644
--- a/drivers/usb/gadget/max3420_udc.c
+++ b/drivers/usb/gadget/max3420_udc.c
@@ -830,7 +830,7 @@ static int max3420_udc_probe(struct udevice *dev)
 	cs = slave_pdata->cs;
 	speed = slave_pdata->max_hz;
 	mode = slave_pdata->mode;
-	spi_get_bus_and_cs(busnum, cs, speed, mode, "spi_generic_drv",
+	spi_get_bus_and_cs(busnum, cs, speed, mode, false, "spi_generic_drv",
 			   NULL, &spid, &udc->slave);
 
 	udc->dev = dev;
diff --git a/include/spi.h b/include/spi.h
index fa9ab12dbe..0aa5fe033c 100644
--- a/include/spi.h
+++ b/include/spi.h
@@ -582,15 +582,16 @@ int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp,
  * @cs:		Chip select to look for
  * @speed:	SPI speed to use for this slave when not available in plat
  * @mode:	SPI mode to use for this slave when not available in plat
+ * @use_dt:     Force usage of SPI speed and SPI mode from DT
  * @drv_name:	Name of driver to attach to this chip select
  * @dev_name:	Name of the new device thus created
  * @busp:	Returns bus device
  * @devp:	Return slave device
  * Return: 0 if found, -ve on error
  */
-int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
-			const char *drv_name, const char *dev_name,
-			struct udevice **busp, struct spi_slave **devp);
+int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode, bool use_dt,
+		       const char *drv_name, const char *dev_name,
+		       struct udevice **busp, struct spi_slave **devp);
 
 /**
  * spi_chip_select() - Get the chip select for a slave
diff --git a/include/spi_flash.h b/include/spi_flash.h
index d33d0dd46a..256878df6a 100644
--- a/include/spi_flash.h
+++ b/include/spi_flash.h
@@ -105,6 +105,10 @@ int spi_flash_probe_bus_cs(unsigned int busnum, unsigned int cs,
 			   unsigned int max_hz, unsigned int spi_mode,
 			   struct udevice **devp);
 
+int spi_flash_probe_bus_cs_default(unsigned int busnum, unsigned int cs,
+				   unsigned int max_hz, unsigned int spi_mode,
+				   struct udevice **devp);
+
 /* Compatibility function - this is the old U-Boot API */
 struct spi_flash *spi_flash_probe(unsigned int bus, unsigned int cs,
 				  unsigned int max_hz, unsigned int spi_mode);
diff --git a/test/dm/spi.c b/test/dm/spi.c
index ee4ad3abaa..2b1f5535c6 100644
--- a/test/dm/spi.c
+++ b/test/dm/spi.c
@@ -47,7 +47,7 @@ static int dm_test_spi_find(struct unit_test_state *uts)
 	/* This finds nothing because we removed the device */
 	ut_asserteq(-ENODEV, spi_find_bus_and_cs(busnum, cs, &bus, &dev));
 	ut_asserteq(-ENODEV, spi_get_bus_and_cs(busnum, cs, speed, mode,
-						NULL, 0, &bus, &slave));
+						false, NULL, 0, &bus, &slave));
 
 	/*
 	 * This forces the device to be re-added, but there is no emulation
@@ -56,7 +56,7 @@ static int dm_test_spi_find(struct unit_test_state *uts)
 	 * a 'partially-inited' device.
 	 */
 	ut_asserteq(-ENODEV, spi_find_bus_and_cs(busnum, cs, &bus, &dev));
-	ut_asserteq(-ENOENT, spi_get_bus_and_cs(busnum, cs, speed, mode,
+	ut_asserteq(-ENOENT, spi_get_bus_and_cs(busnum, cs, speed, mode, false,
 						"jedec_spi_nor", "name", &bus,
 						&slave));
 	sandbox_sf_unbind_emul(state_get_current(), busnum, cs);
@@ -67,7 +67,7 @@ static int dm_test_spi_find(struct unit_test_state *uts)
 	ut_assertok(sandbox_sf_bind_emul(state, busnum, cs, bus, node,
 					 "name"));
 	ut_assertok(spi_find_bus_and_cs(busnum, cs, &bus, &dev));
-	ut_assertok(spi_get_bus_and_cs(busnum, cs, speed, mode,
+	ut_assertok(spi_get_bus_and_cs(busnum, cs, speed, mode, false,
 				       "jedec_spi_nor", "name", &bus, &slave));
 
 	ut_assertok(spi_cs_info(bus, cs, &info));
@@ -77,7 +77,8 @@ static int dm_test_spi_find(struct unit_test_state *uts)
 	ut_assertok(sandbox_sf_bind_emul(state, busnum, cs_b, bus, node,
 					 "name"));
 	ut_asserteq(-EINVAL, spi_get_bus_and_cs(busnum, cs_b, speed, mode,
-				       "jedec_spi_nor", "name", &bus, &slave));
+						false, "jedec_spi_nor", "name",
+						&bus, &slave));
 	ut_asserteq(-EINVAL, spi_cs_info(bus, cs_b, &info));
 	ut_asserteq_ptr(NULL, info.dev);
 
@@ -145,10 +146,10 @@ static int dm_test_spi_claim_bus(struct unit_test_state *uts)
 	const int busnum = 0, cs_a = 0, cs_b = 1, mode = 0;
 
 	/* Get spi slave on CS0 */
-	ut_assertok(spi_get_bus_and_cs(busnum, cs_a, 1000000, mode, NULL, 0,
+	ut_assertok(spi_get_bus_and_cs(busnum, cs_a, 1000000, mode, false, NULL, 0,
 				       &bus, &slave_a));
 	/* Get spi slave on CS1 */
-	ut_assertok(spi_get_bus_and_cs(busnum, cs_b, 1000000, mode, NULL, 0,
+	ut_assertok(spi_get_bus_and_cs(busnum, cs_b, 1000000, mode, false, NULL, 0,
 				       &bus, &slave_b));
 
 	/* Different max_hz, different mode. */
@@ -182,7 +183,7 @@ static int dm_test_spi_xfer(struct unit_test_state *uts)
 	const char dout[5] = {0x9f};
 	unsigned char din[5];
 
-	ut_assertok(spi_get_bus_and_cs(busnum, cs, 1000000, mode, NULL, 0,
+	ut_assertok(spi_get_bus_and_cs(busnum, cs, 1000000, mode, false, NULL, 0,
 				       &bus, &slave));
 	ut_assertok(spi_claim_bus(slave));
 	ut_assertok(spi_xfer(slave, 40, dout, din,
-- 
2.17.1



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