summaryrefslogtreecommitdiff
path: root/arch/arm/mach-omap2/sdrc.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/mach-omap2/sdrc.c')
-rw-r--r--arch/arm/mach-omap2/sdrc.c157
1 files changed, 157 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/sdrc.c b/arch/arm/mach-omap2/sdrc.c
new file mode 100644
index 000000000..dae7e4804
--- /dev/null
+++ b/arch/arm/mach-omap2/sdrc.c
@@ -0,0 +1,157 @@
+/*
+ * SMS/SDRC (SDRAM controller) common code for OMAP2/3
+ *
+ * Copyright (C) 2005, 2008 Texas Instruments Inc.
+ * Copyright (C) 2005, 2008 Nokia Corporation
+ *
+ * Tony Lindgren <tony@atomide.com>
+ * Paul Walmsley
+ * Richard Woodruff <r-woodruff2@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#undef DEBUG
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/errno.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+
+#include "common.h"
+#include "clock.h"
+#include "sdrc.h"
+
+static struct omap_sdrc_params *sdrc_init_params_cs0, *sdrc_init_params_cs1;
+
+void __iomem *omap2_sdrc_base;
+void __iomem *omap2_sms_base;
+
+struct omap2_sms_regs {
+ u32 sms_sysconfig;
+};
+
+static struct omap2_sms_regs sms_context;
+
+/* SDRC_POWER register bits */
+#define SDRC_POWER_EXTCLKDIS_SHIFT 3
+#define SDRC_POWER_PWDENA_SHIFT 2
+#define SDRC_POWER_PAGEPOLICY_SHIFT 0
+
+/**
+ * omap2_sms_save_context - Save SMS registers
+ *
+ * Save SMS registers that need to be restored after off mode.
+ */
+void omap2_sms_save_context(void)
+{
+ sms_context.sms_sysconfig = sms_read_reg(SMS_SYSCONFIG);
+}
+
+/**
+ * omap2_sms_restore_context - Restore SMS registers
+ *
+ * Restore SMS registers that need to be Restored after off mode.
+ */
+void omap2_sms_restore_context(void)
+{
+ sms_write_reg(sms_context.sms_sysconfig, SMS_SYSCONFIG);
+}
+
+/**
+ * omap2_sdrc_get_params - return SDRC register values for a given clock rate
+ * @r: SDRC clock rate (in Hz)
+ * @sdrc_cs0: chip select 0 ram timings **
+ * @sdrc_cs1: chip select 1 ram timings **
+ *
+ * Return pre-calculated values for the SDRC_ACTIM_CTRLA,
+ * SDRC_ACTIM_CTRLB, SDRC_RFR_CTRL and SDRC_MR registers in sdrc_cs[01]
+ * structs,for a given SDRC clock rate 'r'.
+ * These parameters control various timing delays in the SDRAM controller
+ * that are expressed in terms of the number of SDRC clock cycles to
+ * wait; hence the clock rate dependency.
+ *
+ * Supports 2 different timing parameters for both chip selects.
+ *
+ * Note 1: the sdrc_init_params_cs[01] must be sorted rate descending.
+ * Note 2: If sdrc_init_params_cs_1 is not NULL it must be of same size
+ * as sdrc_init_params_cs_0.
+ *
+ * Fills in the struct omap_sdrc_params * for each chip select.
+ * Returns 0 upon success or -1 upon failure.
+ */
+int omap2_sdrc_get_params(unsigned long r,
+ struct omap_sdrc_params **sdrc_cs0,
+ struct omap_sdrc_params **sdrc_cs1)
+{
+ struct omap_sdrc_params *sp0, *sp1;
+
+ if (!sdrc_init_params_cs0)
+ return -1;
+
+ sp0 = sdrc_init_params_cs0;
+ sp1 = sdrc_init_params_cs1;
+
+ while (sp0->rate && sp0->rate != r) {
+ sp0++;
+ if (sdrc_init_params_cs1)
+ sp1++;
+ }
+
+ if (!sp0->rate)
+ return -1;
+
+ *sdrc_cs0 = sp0;
+ *sdrc_cs1 = sp1;
+ return 0;
+}
+
+
+void __init omap2_set_globals_sdrc(void __iomem *sdrc, void __iomem *sms)
+{
+ omap2_sdrc_base = sdrc;
+ omap2_sms_base = sms;
+}
+
+/**
+ * omap2_sdrc_init - initialize SMS, SDRC devices on boot
+ * @sdrc_cs[01]: pointers to a null-terminated list of struct omap_sdrc_params
+ * Support for 2 chip selects timings
+ *
+ * Turn on smart idle modes for SDRAM scheduler and controller.
+ * Program a known-good configuration for the SDRC to deal with buggy
+ * bootloaders.
+ */
+void __init omap2_sdrc_init(struct omap_sdrc_params *sdrc_cs0,
+ struct omap_sdrc_params *sdrc_cs1)
+{
+ u32 l;
+
+ l = sms_read_reg(SMS_SYSCONFIG);
+ l &= ~(0x3 << 3);
+ l |= (0x2 << 3);
+ sms_write_reg(l, SMS_SYSCONFIG);
+
+ l = sdrc_read_reg(SDRC_SYSCONFIG);
+ l &= ~(0x3 << 3);
+ l |= (0x2 << 3);
+ sdrc_write_reg(l, SDRC_SYSCONFIG);
+
+ sdrc_init_params_cs0 = sdrc_cs0;
+ sdrc_init_params_cs1 = sdrc_cs1;
+
+ /* XXX Enable SRFRONIDLEREQ here also? */
+ /*
+ * PWDENA should not be set due to 34xx erratum 1.150 - PWDENA
+ * can cause random memory corruption
+ */
+ l = (1 << SDRC_POWER_EXTCLKDIS_SHIFT) |
+ (1 << SDRC_POWER_PAGEPOLICY_SHIFT);
+ sdrc_write_reg(l, SDRC_POWER);
+ omap2_sms_save_context();
+}