Merge branch 'android-omap-3.0' into android-omap-tuna-3.0

3 files changed, 139 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/dpll44xx.c b/arch/arm/mach-omap2/dpll44xx.c
index 7e509e7..983617f 100644
--- a/arch/arm/mach-omap2/dpll44xx.c
+++ b/arch/arm/mach-omap2/dpll44xx.c
@@ -79,6 +79,35 @@ int omap4_core_dpll_m2_set_rate(struct clk *clk, unsigned long rate)
 	clkdm_wakeup(l3_emif_clkdm);
 
 	/*
+	 * Errata ID: i728
+	 *
+	 * DESCRIPTION:
+	 *
+	 * If during a small window the following three events occur:
+	 *
+	 * 1) The EMIF_PWR_MGMT_CTRL[7:4] REG_SR_TIM SR_TIMING counter expires
+	 * 2) Frequency change update is requested CM_SHADOW_FREQ_CONFIG1
+	 *    FREQ_UPDATE set to 1
+	 * 3) OCP access is requested
+	 *
+	 * There will be clock instability on the DDR interface.
+	 *
+	 * WORKAROUND:
+	 *
+	 * Prevent event 1) while event 2) is happening.
+	 *
+	 * Disable the self-refresh when requesting a frequency change.
+	 * Before requesting a frequency change, program
+	 * EMIF_PWR_MGMT_CTRL[10:8] REG_LP_MODE to 0x0
+	 * (omap_emif_frequency_pre_notify)
+	 *
+	 * When the frequency change is completed, reprogram
+	 * EMIF_PWR_MGMT_CTRL[10:8] REG_LP_MODE to 0x2.
+	 * (omap_emif_frequency_post_notify)
+	 */
+	omap_emif_frequency_pre_notify();
+
+	/*
 	 * Program EMIF timing parameters in EMIF shadow registers
 	 * for targetted DRR clock.
 	 * DDR Clock = core_dpll_m2 / 2
@@ -107,6 +136,9 @@ int omap4_core_dpll_m2_set_rate(struct clk *clk, unsigned long rate)
 				& OMAP4430_FREQ_UPDATE_MASK) == 0),
 				MAX_FREQ_UPDATE_TIMEOUT, i);
 
+	/* Re-enable DDR self refresh */
+	omap_emif_frequency_post_notify();
+
 	/* Configures MEMIF domain back to HW_WKUP */
 	clkdm_allow_idle(l3_emif_clkdm);
 
@@ -150,6 +182,9 @@ int omap4_prcm_freq_update(void)
 	/* Configures MEMIF domain in SW_WKUP */
 	clkdm_wakeup(l3_emif_clkdm);
 
+	/* Disable DDR self refresh (Errata ID: i728) */
+	omap_emif_frequency_pre_notify();
+
 	/*
 	 * FREQ_UPDATE sequence:
 	 * - DLL_OVERRIDE=0 (DLL lock & code must not be overridden
@@ -167,6 +202,9 @@ int omap4_prcm_freq_update(void)
 				& OMAP4430_FREQ_UPDATE_MASK) == 0),
 				MAX_FREQ_UPDATE_TIMEOUT, i);
 
+	/* Re-enable DDR self refresh */
+	omap_emif_frequency_post_notify();
+
 	/* Configures MEMIF domain back to HW_WKUP */
 	clkdm_allow_idle(l3_emif_clkdm);
 
diff --git a/arch/arm/mach-omap2/emif.c b/arch/arm/mach-omap2/emif.c
index 968bcde..8d41bd1 100644
--- a/arch/arm/mach-omap2/emif.c
+++ b/arch/arm/mach-omap2/emif.c
@@ -38,6 +38,7 @@ struct emif_instance {
 	void __iomem *base;
 	u16 irq;
 	struct platform_device *pdev;
+	bool ddr_refresh_disabled;
 };
 static struct emif_instance emif[EMIF_NUM_INSTANCES];
 static struct emif_regs *emif_curr_regs[EMIF_NUM_INSTANCES];
@@ -534,6 +535,47 @@ static u32 get_ddr_phy_ctrl_1(u32 freq, u8 RL)
 }
 
 /*
+ * get_lp_mode - Get the LP Mode of a EMIF instance.
+ *
+ * It returns the REG_LP_MODE of EMIF_PWR_MGMT_CTRL[10:8]
+ * for a EMIF.
+ *
+ */
+static u32 get_lp_mode(u32 emif_nr)
+{
+	u32 temp, lpmode;
+	void __iomem *base = emif[emif_nr].base;
+
+	temp = readl(base + OMAP44XX_EMIF_PWR_MGMT_CTRL);
+	lpmode = (temp & OMAP44XX_REG_LP_MODE_MASK) >>
+			OMAP44XX_REG_LP_MODE_SHIFT;
+
+	return lpmode;
+}
+
+/*
+ * set_lp_mode - Set the LP Mode of a EMIF instance.
+ *
+ * It replaces the REG_LP_MODE of EMIF_PWR_MGMT_CTRL[10:8]
+ * with the new value for a EMIF.
+ *
+ */
+static void set_lp_mode(u32 emif_nr, u32 lpmode)
+{
+	u32 temp;
+	void __iomem *base = emif[emif_nr].base;
+
+	/* Extract current lp mode value */
+	temp = readl(base + OMAP44XX_EMIF_PWR_MGMT_CTRL);
+
+	/* Write out the new lp mode value */
+	temp &= ~OMAP44XX_REG_LP_MODE_MASK;
+	temp |= lpmode << OMAP44XX_REG_LP_MODE_SHIFT;
+	writel(temp, base + OMAP44XX_EMIF_PWR_MGMT_CTRL);
+
+}
+
+/*
  * Get the temperature level of the EMIF instance:
  * Reads the MR4 register of attached SDRAM parts to find out the temperature
  * level. If there are two parts attached(one on each CS), then the temperature
@@ -875,6 +917,8 @@ static int __devinit omap_emif_probe(struct platform_device *pdev)
 
 	pr_info("EMIF%d is enabled with IRQ%d\n", id, emif[id].irq);
 
+	emif[id].ddr_refresh_disabled = false;
+
 	return 0;
 }
 
@@ -1278,6 +1322,61 @@ int omap_emif_setup_registers(u32 freq, u32 volt_state)
 	return err;
 }
 
+
+/*
+ * omap_emif_frequency_pre_notify - Disable DDR self refresh of both EMIFs
+ *
+ * It disables the LP mode if the LP mode of EMIFs was LP_MODE_SELF_REFRESH.
+ *
+ * It should be called before any PRCM frequency update sequence.
+ * After the frequency update sequence, omap_emif_frequency_post_notify
+ * should be called to restore the original LP MODE setting of the EMIFs.
+ *
+ */
+void omap_emif_frequency_pre_notify(void)
+{
+	int emif_num;
+
+	for (emif_num = EMIF1; emif_num < EMIF_NUM_INSTANCES; emif_num++) {
+
+		/*
+		 * Only disable ddr self-refresh
+		 * if ddr self-refresh was enabled
+		 */
+		if (likely(LP_MODE_SELF_REFRESH == get_lp_mode(emif_num))) {
+
+			set_lp_mode(emif_num, LP_MODE_DISABLE);
+			emif[emif_num].ddr_refresh_disabled = true;
+		}
+
+	}
+}
+
+/*
+ * omap_emif_frequency_post_notify - Enable DDR self refresh of both EMIFs
+ *
+ * It restores the LP mode of the EMIFs back to LP_MODE_SELF_REFRESH if it
+ * was previously disabled by omap_emif_frequency_pre_notify()
+ *
+ */
+void omap_emif_frequency_post_notify(void)
+{
+	int emif_num;
+
+	for (emif_num = EMIF1; emif_num < EMIF_NUM_INSTANCES; emif_num++) {
+
+		/*
+		 * Only re-enable ddr self-refresh
+		 * if ddr self-refresh was disabled
+		 */
+		if (likely(emif[emif_num].ddr_refresh_disabled)) {
+
+			set_lp_mode(emif_num, LP_MODE_SELF_REFRESH);
+			emif[emif_num].ddr_refresh_disabled = false;
+		}
+	}
+}
+
 /*
  * omap_emif_setup_device_details - save the SDRAM device details passed
  * from the board file
diff --git a/arch/arm/mach-omap2/include/mach/emif.h b/arch/arm/mach-omap2/include/mach/emif.h
index 99a7c69..d7e1eb9 100644
--- a/arch/arm/mach-omap2/include/mach/emif.h
+++ b/arch/arm/mach-omap2/include/mach/emif.h
@@ -258,6 +258,8 @@ struct emif_regs {
 
 int omap_emif_setup_registers(u32 freq,
 			      u32 volt_state);
+void omap_emif_frequency_pre_notify(void);
+void omap_emif_frequency_post_notify(void);
 int omap_emif_setup_device_details(
 			const struct emif_device_details *emif1_devices,
 			const struct emif_device_details *emif2_devices);