mx6: Enable L2 cache support

Add L2 cache support and enable it by default.

Configure the L2 cache in the same way as done by FSL kernel:
http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git/tree/arch/arm/mach-mx6/mm.c?h=imx_3.0.35_4.1.0

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Dirk Behme <dirk.behme@gmail.com>
Acked-by: Stefano Babic <sbabic@denx.de>

arch/arm/cpu/armv7/mx6/soc.c

@@ -8,6 +8,8 @@
  */
 
 #include <common.h>
+#include <asm/armv7.h>
+#include <asm/pl310.h>
 #include <asm/errno.h>
 #include <asm/io.h>
 #include <asm/arch/imx-regs.h>
@@ -375,3 +377,59 @@ void imx_setup_hdmi(void)
 	writel(reg, &mxc_ccm->chsccdr);
 }
 #endif
+
+#ifndef CONFIG_SYS_L2CACHE_OFF
+#define IOMUXC_GPR11_L2CACHE_AS_OCRAM 0x00000002
+void v7_outer_cache_enable(void)
+{
+	struct pl310_regs *const pl310 = (struct pl310_regs *)L2_PL310_BASE;
+	unsigned int val;
+
+#if defined CONFIG_MX6SL
+	struct iomuxc *iomux = (struct iomuxc *)IOMUXC_BASE_ADDR;
+	val = readl(&iomux->gpr[11]);
+	if (val & IOMUXC_GPR11_L2CACHE_AS_OCRAM) {
+		/* L2 cache configured as OCRAM, reset it */
+		val &= ~IOMUXC_GPR11_L2CACHE_AS_OCRAM;
+		writel(val, &iomux->gpr[11]);
+	}
+#endif
+
+	writel(0x132, &pl310->pl310_tag_latency_ctrl);
+	writel(0x132, &pl310->pl310_data_latency_ctrl);
+
+	val = readl(&pl310->pl310_prefetch_ctrl);
+
+	/* Turn on the L2 I/D prefetch */
+	val |= 0x30000000;
+
+	/*
+	 * The L2 cache controller(PL310) version on the i.MX6D/Q is r3p1-50rel0
+	 * The L2 cache controller(PL310) version on the i.MX6DL/SOLO/SL is r3p2
+	 * But according to ARM PL310 errata: 752271
+	 * ID: 752271: Double linefill feature can cause data corruption
+	 * Fault Status: Present in: r3p0, r3p1, r3p1-50rel0. Fixed in r3p2
+	 * Workaround: The only workaround to this erratum is to disable the
+	 * double linefill feature. This is the default behavior.
+	 */
+
+#ifndef CONFIG_MX6Q
+	val |= 0x40800000;
+#endif
+	writel(val, &pl310->pl310_prefetch_ctrl);
+
+	val = readl(&pl310->pl310_power_ctrl);
+	val |= L2X0_DYNAMIC_CLK_GATING_EN;
+	val |= L2X0_STNDBY_MODE_EN;
+	writel(val, &pl310->pl310_power_ctrl);
+
+	setbits_le32(&pl310->pl310_ctrl, L2X0_CTRL_EN);
+}
+
+void v7_outer_cache_disable(void)
+{
+	struct pl310_regs *const pl310 = (struct pl310_regs *)L2_PL310_BASE;
+
+	clrbits_le32(&pl310->pl310_ctrl, L2X0_CTRL_EN);
+}
+#endif /* !CONFIG_SYS_L2CACHE_OFF */

arch/arm/include/asm/arch-mx6/imx-regs.h

@@ -53,6 +53,7 @@
 #define GLOBAL_TIMER_BASE_ADDR          0x00A00200
 #define PRIVATE_TIMERS_WD_BASE_ADDR     0x00A00600
 #define IC_DISTRIBUTOR_BASE_ADDR        0x00A01000
+#define L2_PL310_BASE			0x00A02000
 #define GPV0_BASE_ADDR                  0x00B00000
 #define GPV1_BASE_ADDR                  0x00C00000
 #define PCIE_ARB_BASE_ADDR              0x01000000

arch/arm/include/asm/pl310.h

@@ -12,6 +12,9 @@
 
 /* Register bit fields */
 #define PL310_AUX_CTRL_ASSOCIATIVITY_MASK	(1 << 16)
+#define L2X0_DYNAMIC_CLK_GATING_EN		(1 << 1)
+#define L2X0_STNDBY_MODE_EN			(1 << 0)
+#define L2X0_CTRL_EN				1
 
 struct pl310_regs {
 	u32 pl310_cache_id;
@@ -47,6 +50,24 @@ struct pl310_regs {
 	u32 pad9[1];
 	u32 pl310_clean_inv_line_idx;
 	u32 pl310_clean_inv_way;
+	u32 pad10[64];
+	u32 pl310_lockdown_dbase;
+	u32 pl310_lockdown_ibase;
+	u32 pad11[190];
+	u32 pl310_addr_filter_start;
+	u32 pl310_addr_filter_end;
+	u32 pad12[190];
+	u32 pl310_test_operation;
+	u32 pad13[3];
+	u32 pl310_line_data;
+	u32 pad14[7];
+	u32 pl310_line_tag;
+	u32 pad15[3];
+	u32 pl310_debug_ctrl;
+	u32 pad16[7];
+	u32 pl310_prefetch_ctrl;
+	u32 pad17[7];
+	u32 pl310_power_ctrl;
 };
 
 void pl310_inval_all(void);

include/configs/mx6_common.h

@@ -22,4 +22,9 @@
 #define CONFIG_ARM_ERRATA_751472
 #define CONFIG_BOARD_POSTCLK_INIT
 
+#ifndef CONFIG_SYS_L2CACHE_OFF
+#define CONFIG_SYS_L2_PL310
+#define CONFIG_SYS_PL310_BASE	L2_PL310_BASE
+#endif
+
 #endif