[PATCH V2 2/3] ARM: imx: add i.MX7ULP SoC revision support

From: Anson Huang
Date: Fri Jan 11 2019 - 01:22:57 EST


i.MX7ULP SoC's revision info is inside the SIM module,
bit[31:28] of JTAG_ID register defines revision as below
from B0:

0001 B0
0010 B1

This patch adds SoC revision support for i.MX7ULP, test
result as below:

root@imx7ulp-evk ~$ cat /sys/devices/soc0/revision
2.1

Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx>
---
arch/arm/mach-imx/mach-imx7ulp.c | 39 +++++++++++++++++++++++++++++++++++++++
1 file changed, 39 insertions(+)

diff --git a/arch/arm/mach-imx/mach-imx7ulp.c b/arch/arm/mach-imx/mach-imx7ulp.c
index 19c5b30..11ac71a 100644
--- a/arch/arm/mach-imx/mach-imx7ulp.c
+++ b/arch/arm/mach-imx/mach-imx7ulp.c
@@ -6,18 +6,57 @@
*/

#include <linux/irqchip.h>
+#include <linux/mfd/syscon.h>
#include <linux/of_platform.h>
+#include <linux/regmap.h>
#include <asm/mach/arch.h>

#include "common.h"
#include "cpuidle.h"
#include "hardware.h"

+#define SIM_JTAG_ID_REG 0x8c
+
+static void __init imx7ulp_set_revision(void)
+{
+ struct regmap *sim;
+ u32 revision;
+
+ sim = syscon_regmap_lookup_by_compatible("fsl,imx7ulp-sim");
+ if (IS_ERR(sim)) {
+ pr_warn("failed to find fsl,imx7ulp-sim regmap!\n");
+ return;
+ }
+
+ if (regmap_read(sim, SIM_JTAG_ID_REG, &revision)) {
+ pr_warn("failed to read sim regmap!\n");
+ return;
+ }
+
+ /*
+ * bit[31:28] of JTAG_ID register defines revision as below from B0:
+ * 0001 B0
+ * 0010 B1
+ */
+ switch (revision >> 28) {
+ case 1:
+ imx_set_soc_revision(IMX_CHIP_REVISION_2_0);
+ break;
+ case 2:
+ imx_set_soc_revision(IMX_CHIP_REVISION_2_1);
+ break;
+ default:
+ imx_set_soc_revision(IMX_CHIP_REVISION_1_0);
+ break;
+ }
+}
+
static void __init imx7ulp_init_machine(void)
{
imx7ulp_pm_init();

mxc_set_cpu_type(MXC_CPU_IMX7ULP);
+ imx7ulp_set_revision();
of_platform_default_populate(NULL, NULL, imx_soc_device_init());
}

--
2.7.4