[U-Boot] [PATCH v4 20/29] dm: Convert spi_flash_probe() and 'sf probe' to use driver model

[Simon Glass]

We want the SPI flash probing feature to operate as a standard driver.
Add a driver for the basic probing feature used by most boards. This
will be activated by device_probe() as with any other driver.

The 'sf probe' command currently keeps track of the SPI slave that it
last used. This doesn't work with driver model, since some other driver
or system may have probed the device and have access to it too. On the
other hand, if we try to probe a device twice the second probe is a nop
with driver model.

Fix this by searching for the matching device, removing it, and then
probing it again. This should work as expected regardless of other device
activity.

Signed-off-by: Simon Glass <sjg at chromium.org>
Reviewed-by: Jagannadha Sutradharudu Teki <jagannadh.teki at gmail.com>
---

Changes in v4: None
Changes in v3:
- Add a debug() in the probe method
- Make sure the old device is both removed and unbound in 'sf probe'

Changes in v2: None

 common/cmd_sf.c            | 25 ++++++++++++++++++
 drivers/mtd/spi/sf_probe.c | 66 ++++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 89 insertions(+), 2 deletions(-)

diff --git a/common/cmd_sf.c b/common/cmd_sf.c
index 42d89d4..95a6f89 100644
--- a/common/cmd_sf.c
+++ b/common/cmd_sf.c
@@ -8,11 +8,13 @@
 
 #include <common.h>
 #include <div64.h>
+#include <dm.h>
 #include <malloc.h>
 #include <spi.h>
 #include <spi_flash.h>
 
 #include <asm/io.h>
+#include <dm/device-internal.h>
 
 static struct spi_flash *flash;
 
@@ -81,7 +83,12 @@ 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;
+#ifdef CONFIG_DM_SPI_FLASH
+	struct udevice *new, *bus_dev;
+	int ret;
+#else
 	struct spi_flash *new;
+#endif
 
 	if (argc >= 2) {
 		cs = simple_strtoul(argv[1], &endp, 0);
@@ -109,6 +116,23 @@ static int do_spi_flash_probe(int argc, char * const argv[])
 			return -1;
 	}
 
+#ifdef CONFIG_DM_SPI_FLASH
+	/* Remove the old device, otherwise probe will just be a nop */
+	ret = spi_find_bus_and_cs(bus, cs, &bus_dev, &new);
+	if (!ret) {
+		device_remove(new);
+		device_unbind(new);
+	}
+	flash = NULL;
+	ret = spi_flash_probe_bus_cs(bus, cs, speed, mode, &new);
+	if (ret) {
+		printf("Failed to initialize SPI flash at %u:%u (error %d)\n",
+		       bus, cs, ret);
+		return 1;
+	}
+
+	flash = new->uclass_priv;
+#else
 	new = spi_flash_probe(bus, cs, speed, mode);
 	if (!new) {
 		printf("Failed to initialize SPI flash at %u:%u\n", bus, cs);
@@ -118,6 +142,7 @@ static int do_spi_flash_probe(int argc, char * const argv[])
 	if (flash)
 		spi_flash_free(flash);
 	flash = new;
+#endif
 
 	return 0;
 }
diff --git a/drivers/mtd/spi/sf_probe.c b/drivers/mtd/spi/sf_probe.c
index 212a825..2636426 100644
--- a/drivers/mtd/spi/sf_probe.c
+++ b/drivers/mtd/spi/sf_probe.c
@@ -9,6 +9,7 @@
  */
 
 #include <common.h>
+#include <dm.h>
 #include <errno.h>
 #include <fdtdec.h>
 #include <malloc.h>
@@ -131,13 +132,15 @@ static int spi_flash_validate_params(struct spi_slave *spi, u8 *idcode,
 	flash->dual_flash = flash->spi->option;
 
 	/* Assign spi_flash ops */
+#ifndef CONFIG_DM_SPI_FLASH
 	flash->write = spi_flash_cmd_write_ops;
-#ifdef CONFIG_SPI_FLASH_SST
+#if defined(CONFIG_SPI_FLASH_SST)
 	if (params->flags & SST_WP)
 		flash->write = sst_write_wp;
 #endif
 	flash->erase = spi_flash_cmd_erase_ops;
 	flash->read = spi_flash_cmd_read_ops;
+#endif
 
 	/* Compute the flash size */
 	flash->shift = (flash->dual_flash & SF_DUAL_PARALLEL_FLASH) ? 1 : 0;
@@ -398,7 +401,8 @@ err_read_id:
 	return ret;
 }
 
-static struct spi_flash *spi_flash_probe_tail(struct spi_slave *bus)
+#ifndef CONFIG_DM_SPI_FLASH
+struct spi_flash *spi_flash_probe_tail(struct spi_slave *bus)
 {
 	struct spi_flash *flash;
 
@@ -443,3 +447,61 @@ void spi_flash_free(struct spi_flash *flash)
 	spi_free_slave(flash->spi);
 	free(flash);
 }
+
+#else /* defined CONFIG_DM_SPI_FLASH */
+
+static int spi_flash_std_read(struct udevice *dev, u32 offset, size_t len,
+			      void *buf)
+{
+	struct spi_flash *flash = dev->uclass_priv;
+
+	return spi_flash_cmd_read_ops(flash, offset, len, buf);
+}
+
+int spi_flash_std_write(struct udevice *dev, u32 offset, size_t len,
+			const void *buf)
+{
+	struct spi_flash *flash = dev->uclass_priv;
+
+	return spi_flash_cmd_write_ops(flash, offset, len, buf);
+}
+
+int spi_flash_std_erase(struct udevice *dev, u32 offset, size_t len)
+{
+	struct spi_flash *flash = dev->uclass_priv;
+
+	return spi_flash_cmd_erase_ops(flash, offset, len);
+}
+
+int spi_flash_std_probe(struct udevice *dev)
+{
+	struct spi_slave *slave = dev_get_parentdata(dev);
+	struct spi_flash *flash;
+
+	flash = dev->uclass_priv;
+	flash->dev = dev;
+	debug("%s: slave=%p, cs=%d\n", __func__, slave, slave->cs);
+	return spi_flash_probe_slave(slave, flash);
+}
+
+static const struct dm_spi_flash_ops spi_flash_std_ops = {
+	.read = spi_flash_std_read,
+	.write = spi_flash_std_write,
+	.erase = spi_flash_std_erase,
+};
+
+static const struct udevice_id spi_flash_std_ids[] = {
+	{ .compatible = "spi-flash" },
+	{ }
+};
+
+U_BOOT_DRIVER(spi_flash_std) = {
+	.name		= "spi_flash_std",
+	.id		= UCLASS_SPI_FLASH,
+	.of_match	= spi_flash_std_ids,
+	.probe		= spi_flash_std_probe,
+	.priv_auto_alloc_size = sizeof(struct spi_flash),
+	.ops		= &spi_flash_std_ops,
+};
+
+#endif /* CONFIG_DM_SPI_FLASH */
-- 
2.1.0.rc2.206.gedb03e5