soc: imx: gpc: restrict register range for regmap access

GPC registers are NOT continuous, some registers are
reserved and accessing them from userspace will trigger
external abort, add regmap register access table to
avoid below abort:

root@imx6slevk:~# cat /sys/kernel/debug/regmap/20dc000.gpc/registers
[  108.480477] Unhandled fault: imprecise external abort (0x1406) at 0xb6db5004
[  108.487985] pgd = 42b54bfd
[  108.490741] [b6db5004] *pgd=ba1b7831
[  108.494386] Internal error: : 1406 [#1] SMP ARM
[  108.498943] Modules linked in:
[  108.502043] CPU: 0 PID: 389 Comm: cat Not tainted 4.18.0-rc1-00074-gc9f1f60-dirty #482
[  108.509982] Hardware name: Freescale i.MX6 SoloLite (Device Tree)
[  108.516123] PC is at regmap_mmio_read32le+0x20/0x24
[  108.521031] LR is at regmap_mmio_read+0x40/0x60
[  108.525586] pc : [<c059cf74>]    lr : [<c059d1ac>]    psr: 20060093
[  108.531875] sp : eccf1d98  ip : eccf1da8  fp : eccf1da4
[  108.537122] r10: ec2d3800  r9 : eccf1f60  r8 : ecfc0000
[  108.542370] r7 : eccf1e2c  r6 : eccf1e2c  r5 : 00000028  r4 : ec338e00
[  108.548920] r3 : 00000000  r2 : eccf1e2c  r1 : f0980028  r0 : 00000000
[  108.555474] Flags: nzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment none
[  108.562720] Control: 10c5387d  Table: acf4004a  DAC: 00000051
[  108.568491] Process cat (pid: 389, stack limit = 0xd4318a65)
[  108.574174] Stack: (0xeccf1d98 to 0xeccf2000)

Fixes: 721cabf6 ("soc: imx: move PGC handling to a new GPC driver")
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

drivers/soc/imx/gpc.c

@@ -27,9 +27,16 @@
 #define GPC_PGC_SW2ISO_SHIFT	0x8
 #define GPC_PGC_SW_SHIFT	0x0
 
+#define GPC_PGC_PCI_PDN		0x200
+#define GPC_PGC_PCI_SR		0x20c
+
 #define GPC_PGC_GPU_PDN		0x260
 #define GPC_PGC_GPU_PUPSCR	0x264
 #define GPC_PGC_GPU_PDNSCR	0x268
+#define GPC_PGC_GPU_SR		0x26c
+
+#define GPC_PGC_DISP_PDN	0x240
+#define GPC_PGC_DISP_SR		0x24c
 
 #define GPU_VPU_PUP_REQ		BIT(1)
 #define GPU_VPU_PDN_REQ		BIT(0)
@@ -318,10 +325,24 @@ static const struct of_device_id imx_gpc_dt_ids[] = {
 	{ }
 };
 
+static const struct regmap_range yes_ranges[] = {
+	regmap_reg_range(GPC_CNTR, GPC_CNTR),
+	regmap_reg_range(GPC_PGC_PCI_PDN, GPC_PGC_PCI_SR),
+	regmap_reg_range(GPC_PGC_GPU_PDN, GPC_PGC_GPU_SR),
+	regmap_reg_range(GPC_PGC_DISP_PDN, GPC_PGC_DISP_SR),
+};
+
+static const struct regmap_access_table access_table = {
+	.yes_ranges	= yes_ranges,
+	.n_yes_ranges	= ARRAY_SIZE(yes_ranges),
+};
+
 static const struct regmap_config imx_gpc_regmap_config = {
 	.reg_bits = 32,
 	.val_bits = 32,
 	.reg_stride = 4,
+	.rd_table = &access_table,
+	.wr_table = &access_table,
 	.max_register = 0x2ac,
 };