arm: mx23: Fix VDDMEM misconfiguration

The VDDMEM ramped up in very weird way as it was horribly misconfigured.
Instead of setting up VDDMEM in one swipe, let it rise slowly the same
way as VDDD and VDDA in spl_power_init.c and then only clear ILIMIT before
memory gets inited. This makes sure the VDDMEM rises sanely, not jumps up
and down as it did till now.

The VDDMEM prior to this change did this:
     2V0____   .--------2V5
       |    `--'
 0V____|

The VDDMEM now does this:
    2V0_____,-----------2V5
      /
 0V__|

Moreover, VDDIO on MX23 uses 25mV steps while MX28 uses 50mV steps,
fix this difference too.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Otavio Salvador <otavio@ossystems.com.br>
Cc: Stefano Babic <sbabic@denx.de>

arch/arm/cpu/arm926ejs/mxs/spl_mem_init.c

@@ -256,17 +256,9 @@ static void mx23_mem_setup_vddmem(void)
 	struct mxs_power_regs *power_regs =
 		(struct mxs_power_regs *)MXS_POWER_BASE;
 
-	writel((0x10 << POWER_VDDMEMCTRL_TRG_OFFSET) |
-		POWER_VDDMEMCTRL_ENABLE_ILIMIT |
-		POWER_VDDMEMCTRL_ENABLE_LINREG |
-		POWER_VDDMEMCTRL_PULLDOWN_ACTIVE,
-		&power_regs->hw_power_vddmemctrl);
+	clrbits_le32(&power_regs->hw_power_vddmemctrl,
+		POWER_VDDMEMCTRL_ENABLE_ILIMIT);
 
-	early_delay(10000);
-
-	writel((0x10 << POWER_VDDMEMCTRL_TRG_OFFSET) |
-		POWER_VDDMEMCTRL_ENABLE_LINREG,
-		&power_regs->hw_power_vddmemctrl);
 }
 
 static void mx23_mem_init(void)

arch/arm/cpu/arm926ejs/mxs/spl_power_init.c

@@ -687,6 +687,12 @@ static void mxs_power_configure_power_source(void)
 	mxs_init_batt_bo();
 
 	mxs_switch_vddd_to_dcdc_source();
+
+#ifdef CONFIG_MX23
+	/* Fire up the VDDMEM LinReg now that we're all set. */
+	writel(POWER_VDDMEMCTRL_ENABLE_LINREG | POWER_VDDMEMCTRL_ENABLE_ILIMIT,
+		&power_regs->hw_power_vddmemctrl);
+#endif
 }
 
 static void mxs_enable_output_rail_protection(void)
@@ -781,7 +787,11 @@ struct mxs_vddx_cfg {
 static const struct mxs_vddx_cfg mxs_vddio_cfg = {
 	.reg			= &(((struct mxs_power_regs *)MXS_POWER_BASE)->
 					hw_power_vddioctrl),
+#if defined(CONFIG_MX23)
+	.step_mV		= 25,
+#else
 	.step_mV		= 50,
+#endif
 	.lowest_mV		= 2800,
 	.powered_by_linreg	= mxs_get_vddio_power_source_off,
 	.trg_mask		= POWER_VDDIOCTRL_TRG_MASK,
@@ -804,6 +814,21 @@ static const struct mxs_vddx_cfg mxs_vddd_cfg = {
 	.bo_offset_offset	= POWER_VDDDCTRL_BO_OFFSET_OFFSET,
 };
 
+#ifdef CONFIG_MX23
+static const struct mxs_vddx_cfg mxs_vddmem_cfg = {
+	.reg			= &(((struct mxs_power_regs *)MXS_POWER_BASE)->
+					hw_power_vddmemctrl),
+	.step_mV		= 50,
+	.lowest_mV		= 1700,
+	.powered_by_linreg	= NULL,
+	.trg_mask		= POWER_VDDMEMCTRL_TRG_MASK,
+	.bo_irq			= 0,
+	.bo_enirq		= 0,
+	.bo_offset_mask		= 0,
+	.bo_offset_offset	= 0,
+};
+#endif
+
 static void mxs_power_set_vddx(const struct mxs_vddx_cfg *cfg,
 				uint32_t new_target, uint32_t new_brownout)
 {
@@ -821,9 +846,10 @@ static void mxs_power_set_vddx(const struct mxs_vddx_cfg *cfg,
 	cur_target += cfg->lowest_mV;
 
 	adjust_up = new_target > cur_target;
-	powered_by_linreg = cfg->powered_by_linreg();
+	if (cfg->powered_by_linreg)
+		powered_by_linreg = cfg->powered_by_linreg();
 
-	if (adjust_up) {
+	if (adjust_up && cfg->bo_irq) {
 		if (powered_by_linreg) {
 			bo_int = readl(cfg->reg);
 			clrbits_le32(cfg->reg, cfg->bo_enirq);
@@ -864,14 +890,16 @@ static void mxs_power_set_vddx(const struct mxs_vddx_cfg *cfg,
 		cur_target += cfg->lowest_mV;
 	} while (new_target > cur_target);
 
-	if (adjust_up && powered_by_linreg) {
-		writel(cfg->bo_irq, &power_regs->hw_power_ctrl_clr);
-		if (bo_int & cfg->bo_enirq)
-			setbits_le32(cfg->reg, cfg->bo_enirq);
-	}
+	if (cfg->bo_irq) {
+		if (adjust_up && powered_by_linreg) {
+			writel(cfg->bo_irq, &power_regs->hw_power_ctrl_clr);
+			if (bo_int & cfg->bo_enirq)
+				setbits_le32(cfg->reg, cfg->bo_enirq);
+		}
 
-	clrsetbits_le32(cfg->reg, cfg->bo_offset_mask,
-			new_brownout << cfg->bo_offset_offset);
+		clrsetbits_le32(cfg->reg, cfg->bo_offset_mask,
+				new_brownout << cfg->bo_offset_offset);
+	}
 }
 
 static void mxs_setup_batt_detect(void)
@@ -910,7 +938,9 @@ void mxs_power_init(void)
 
 	mxs_power_set_vddx(&mxs_vddio_cfg, 3300, 3150);
 	mxs_power_set_vddx(&mxs_vddd_cfg, 1500, 1000);
-
+#ifdef CONFIG_MX23
+	mxs_power_set_vddx(&mxs_vddmem_cfg, 2500, 1700);
+#endif
 	writel(POWER_CTRL_VDDD_BO_IRQ | POWER_CTRL_VDDA_BO_IRQ |
 		POWER_CTRL_VDDIO_BO_IRQ | POWER_CTRL_VDD5V_DROOP_IRQ |
 		POWER_CTRL_VBUS_VALID_IRQ | POWER_CTRL_BATT_BO_IRQ |