ARM: mvebu: Use system controller to get the soc id when possible

On Armada 38x it is possible to get the SoC Id and the revision
without using the PCI register. Accessing the PCI registers implies
enabling its clock and, because of the initialization issue, not
keeping them enable. So if possible it is better to avoid it.

Armada 370 and Armada XP provides the SoC ID values from the system
controller but not the revision.

Armada 375 provides both but the SoC ID value looks buggy (0x6660
instead of 0x6720).

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1403538128-27859-1-git-send-email-gregory.clement@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

1 files changed, 19 insertions, 0 deletions

diff --git a/arch/arm/mach-mvebu/system-controller.c b/arch/arm/mach-mvebu/system-controller.c
index 0c5524ac75b7..b2b4e3d6558c 100644
--- a/arch/arm/mach-mvebu/system-controller.c
+++ b/arch/arm/mach-mvebu/system-controller.c
@@ -39,6 +39,9 @@ struct mvebu_system_controller {
 	u32 system_soft_reset;
 
 	u32 resume_boot_addr;
+
+	u32 dev_id;
+	u32 rev_id;
 };
 static struct mvebu_system_controller *mvebu_sc;
 
@@ -47,6 +50,8 @@ static const struct mvebu_system_controller armada_370_xp_system_controller = {
 	.system_soft_reset_offset = 0x64,
 	.rstoutn_mask_reset_out_en = 0x1,
 	.system_soft_reset = 0x1,
+	.dev_id = 0x38,
+	.rev_id = 0x3c,
 };
 
 static const struct mvebu_system_controller armada_375_system_controller = {
@@ -55,6 +60,8 @@ static const struct mvebu_system_controller armada_375_system_controller = {
 	.rstoutn_mask_reset_out_en = 0x1,
 	.system_soft_reset = 0x1,
 	.resume_boot_addr = 0xd4,
+	.dev_id = 0x38,
+	.rev_id = 0x3c,
 };
 
 static const struct mvebu_system_controller orion_system_controller = {
@@ -101,6 +108,18 @@ void mvebu_restart(enum reboot_mode mode, const char *cmd)
 		;
 }
 
+int mvebu_system_controller_get_soc_id(u32 *dev, u32 *rev)
+{
+	if (of_machine_is_compatible("marvell,armada380") &&
+		system_controller_base) {
+		*dev = readl(system_controller_base + mvebu_sc->dev_id) >> 16;
+		*rev = (readl(system_controller_base + mvebu_sc->rev_id) >> 8)
+			& 0xF;
+		return 0;
+	} else
+		return -ENODEV;
+}
+
 #ifdef CONFIG_SMP
 void mvebu_system_controller_set_cpu_boot_addr(void *boot_addr)
 {