MLK-11281-9 ARM: imx: add debug uart io save/restore for lpsr

When exit from lpsr mode, iomuxc's io/pad settings will
be lost, although driver resume callback will restore
module io settings from sleep mode to default mode, debug
uart needs to be enabled earlier to support
"no_console_suspend" case.

Signed-off-by: Anson Huang <b20788@freescale.com>

diff --git a/arch/arm/mach-imx/pm-imx7.c b/arch/arm/mach-imx/pm-imx7.c
index 2ea167b..747b0e7 100644 (file)
--- a/arch/arm/mach-imx/pm-imx7.c
+++ b/arch/arm/mach-imx/pm-imx7.c
@@ -59,6 +59,12 @@
 #define UART_UTS       0xb4
 
 #define MAX_IOMUXC_GPR                 23
+#define MAX_UART_IO                    4
+
+#define UART_RX_IO     0x128
+#define UART_RX_PAD    0x398
+#define UART_TX_IO     0x12c
+#define UART_TX_PAD    0x39c
 
 extern unsigned long iram_tlb_base_addr;
 extern unsigned long iram_tlb_phys_addr;
@@ -73,10 +79,12 @@ static void __iomem *ccm_base;
 static void __iomem *lpsr_base;
 static void __iomem *console_base;
 static void __iomem *suspend_ocram_base;
+static void __iomem *iomuxc_base;
 static void (*imx7_suspend_in_ocram_fn)(void __iomem *ocram_vbase);
 struct imx7_cpu_pm_info *pm_info;
 static bool lpsr_enabled;
 static u32 iomuxc_gpr[MAX_IOMUXC_GPR];
+static u32 uart1_io[MAX_UART_IO];
 /*
  * suspend ocram space layout:
  * ======================== high address ======================
@@ -303,6 +311,15 @@ static void imx7_console_save(unsigned int *regs)
        regs[9] = readl_relaxed(console_base + UART_UTS);
 }
 
+static void imx7_console_io_save(void)
+{
+       /* save uart1 io, driver resume is too late */
+       uart1_io[0] = readl_relaxed(iomuxc_base + UART_RX_IO);
+       uart1_io[1] = readl_relaxed(iomuxc_base + UART_RX_PAD);
+       uart1_io[2] = readl_relaxed(iomuxc_base + UART_TX_IO);
+       uart1_io[3] = readl_relaxed(iomuxc_base + UART_TX_PAD);
+}
+
 static void imx7_console_restore(unsigned int *regs)
 {
        if (!console_base)
@@ -320,6 +337,15 @@ static void imx7_console_restore(unsigned int *regs)
        writel_relaxed(regs[3], console_base + UART_UCR4);
 }
 
+static void imx7_console_io_restore(void)
+{
+       /* restore uart1 io */
+       writel_relaxed(uart1_io[0], iomuxc_base + UART_RX_IO);
+       writel_relaxed(uart1_io[1], iomuxc_base + UART_RX_PAD);
+       writel_relaxed(uart1_io[2], iomuxc_base + UART_TX_IO);
+       writel_relaxed(uart1_io[3], iomuxc_base + UART_TX_PAD);
+}
+
 static int imx7_suspend_finish(unsigned long val)
 {
        if (!imx7_suspend_in_ocram_fn) {
@@ -376,6 +402,7 @@ static int imx7_pm_enter(suspend_state_t state)
                        memcpy(ocram_saved_in_ddr, ocram_base, ocram_size);
                        if (lpsr_enabled) {
                                imx7_pm_set_lpsr_resume_addr(pm_info->resume_addr);
+                               imx7_console_io_save();
                                memcpy(lpm_ocram_saved_in_ddr, lpm_ocram_base,
                                        lpm_ocram_size);
                                imx7_iomuxc_gpr_save();
@@ -386,6 +413,7 @@ static int imx7_pm_enter(suspend_state_t state)
                cpu_suspend(0, imx7_suspend_finish);
 
                if (imx7_pm_is_resume_from_lpsr()) {
+                       imx7_console_io_restore();
                        memcpy(lpm_ocram_base, lpm_ocram_saved_in_ddr,
                                lpm_ocram_size);
                        imx7_iomuxc_gpr_restore();
@@ -677,6 +705,12 @@ void __init imx7d_pm_init(void)
                lpm_ocram_size = resource_size(&res);
                lpm_ocram_saved_in_ddr = kzalloc(lpm_ocram_size, GFP_KERNEL);
                WARN_ON(!lpm_ocram_saved_in_ddr);
+
+               np = of_find_node_by_path(
+                       "/soc/aips-bus@30000000/iomuxc@30330000");
+               if (np)
+                       iomuxc_base = of_iomap(np, 0);
+               WARN_ON(!iomuxc_base);
        }
 
        if (imx_ddrc_get_ddr_type() == IMX_DDR_TYPE_LPDDR3