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Subject[PATCH 5/6] mtd: spi-nor: aspeed: Don't automatically attach reserved chips
Date
With this change, any flash chips under the controller that are marked
with a DT status of "reserved" will be created, but not automatically
attached. Userspace can later request that they be attached using the
attach_chip sysfs file.

This is to accommodate situations where a chip may be (for example)
shared with another controller external to the SoC and require
userspace to arbitrate access to it prior to actually attaching it.
(such as a firmware SPI flash shared between a BMC and the host
system).

Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
---
drivers/mtd/spi-nor/controllers/aspeed-smc.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/spi-nor/controllers/aspeed-smc.c b/drivers/mtd/spi-nor/controllers/aspeed-smc.c
index da49192a8220..328b008fafb2 100644
--- a/drivers/mtd/spi-nor/controllers/aspeed-smc.c
+++ b/drivers/mtd/spi-nor/controllers/aspeed-smc.c
@@ -826,10 +826,14 @@ static int aspeed_smc_setup_flash(struct aspeed_smc_controller *controller,
unsigned int cs;
int ret = -ENODEV;

- for_each_available_child_of_node(np, child) {
+ for_each_child_of_node(np, child) {
struct aspeed_smc_chip *chip;
struct spi_nor *nor;

+ /* Skip disabled nodes, but include reserved ones for later attachment */
+ if (!of_device_is_available(child) && !of_device_is_reserved(child))
+ continue;
+
/* This driver does not support NAND or NOR flash devices. */
if (!of_device_is_compatible(child, "jedec,spi-nor"))
continue;
@@ -873,6 +877,9 @@ static int aspeed_smc_setup_flash(struct aspeed_smc_controller *controller,

controller->chips[cs] = chip;

+ if (of_device_is_reserved(child))
+ continue;
+
ret = aspeed_smc_register_chip(chip);
if (ret)
break;
--
2.33.0
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