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authorJoel Stanley <joel@jms.id.au>2018-02-19 10:24:22 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-03-15 20:20:51 +0300
commitf4d029098428da68b47eaba8094b5c0887a9edc8 (patch)
tree9678ad190c2581b051061a5a35b711f2ef633dac /drivers/misc
parent99aad9e3a9d28c1b998cb157c85e17db957e8ae5 (diff)
downloadlinux-f4d029098428da68b47eaba8094b5c0887a9edc8.tar.xz
misc: aspeed-lpc-ctrl: Enable FWH and A2H bridge cycles
To date this driver has relied on prevous state from out of tree hacks and vendor u-boot trees in order to have the host be able to access data over the LPC bus. Now we explicitly enable the AHB to LPC bridge and FWH cycles from when the user first configures the address to map. We chose to do this then as before that time there is no way for the kernel to know where it is safe to point the LPC window. Tested-by: Lei YU <mine260309@gmail.com> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc')
-rw-r--r--drivers/misc/aspeed-lpc-ctrl.c18
1 files changed, 16 insertions, 2 deletions
diff --git a/drivers/misc/aspeed-lpc-ctrl.c b/drivers/misc/aspeed-lpc-ctrl.c
index 1827b7aa6674..a024f8042259 100644
--- a/drivers/misc/aspeed-lpc-ctrl.c
+++ b/drivers/misc/aspeed-lpc-ctrl.c
@@ -21,6 +21,10 @@
#define DEVICE_NAME "aspeed-lpc-ctrl"
+#define HICR5 0x0
+#define HICR5_ENL2H BIT(8)
+#define HICR5_ENFWH BIT(10)
+
#define HICR7 0x8
#define HICR8 0xc
@@ -155,8 +159,18 @@ static long aspeed_lpc_ctrl_ioctl(struct file *file, unsigned int cmd,
if (rc)
return rc;
- return regmap_write(lpc_ctrl->regmap, HICR8,
- (~(map.size - 1)) | ((map.size >> 16) - 1));
+ rc = regmap_write(lpc_ctrl->regmap, HICR8,
+ (~(map.size - 1)) | ((map.size >> 16) - 1));
+ if (rc)
+ return rc;
+
+ /*
+ * Enable LPC FHW cycles. This is required for the host to
+ * access the regions specified.
+ */
+ return regmap_update_bits(lpc_ctrl->regmap, HICR5,
+ HICR5_ENFWH | HICR5_ENL2H,
+ HICR5_ENFWH | HICR5_ENL2H);
}
return -EINVAL;