ARM: mx51: Implement code to allow mx51 to enter WFI
Implement code for MX51 that allows the SoC to enter WFI when
arch_idle is called.
This patch is also necessary for correctly suspending the system.
Signed-off-by: Dinh Nguyen <Dinh.Nguyen@freescale.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
diff --git a/arch/arm/mach-mx5/system.c b/arch/arm/mach-mx5/system.c
new file mode 100644
index 0000000..76ae8dc
--- /dev/null
+++ b/arch/arm/mach-mx5/system.c
@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
+ */
+
+/*
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <mach/hardware.h>
+#include "crm_regs.h"
+
+/* set cpu low power mode before WFI instruction. This function is called
+ * mx5 because it can be used for mx50, mx51, and mx53.*/
+void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode)
+{
+ u32 plat_lpc, arm_srpgcr, ccm_clpcr;
+ u32 empgc0, empgc1;
+ int stop_mode = 0;
+
+ /* always allow platform to issue a deep sleep mode request */
+ plat_lpc = __raw_readl(MXC_CORTEXA8_PLAT_LPC) &
+ ~(MXC_CORTEXA8_PLAT_LPC_DSM);
+ ccm_clpcr = __raw_readl(MXC_CCM_CLPCR) & ~(MXC_CCM_CLPCR_LPM_MASK);
+ arm_srpgcr = __raw_readl(MXC_SRPG_ARM_SRPGCR) & ~(MXC_SRPGCR_PCR);
+ empgc0 = __raw_readl(MXC_SRPG_EMPGC0_SRPGCR) & ~(MXC_SRPGCR_PCR);
+ empgc1 = __raw_readl(MXC_SRPG_EMPGC1_SRPGCR) & ~(MXC_SRPGCR_PCR);
+
+ switch (mode) {
+ case WAIT_CLOCKED:
+ break;
+ case WAIT_UNCLOCKED:
+ ccm_clpcr |= 0x1 << MXC_CCM_CLPCR_LPM_OFFSET;
+ break;
+ case WAIT_UNCLOCKED_POWER_OFF:
+ case STOP_POWER_OFF:
+ plat_lpc |= MXC_CORTEXA8_PLAT_LPC_DSM
+ | MXC_CORTEXA8_PLAT_LPC_DBG_DSM;
+ if (mode == WAIT_UNCLOCKED_POWER_OFF) {
+ ccm_clpcr |= 0x1 << MXC_CCM_CLPCR_LPM_OFFSET;
+ ccm_clpcr &= ~MXC_CCM_CLPCR_VSTBY;
+ ccm_clpcr &= ~MXC_CCM_CLPCR_SBYOS;
+ stop_mode = 0;
+ } else {
+ ccm_clpcr |= 0x2 << MXC_CCM_CLPCR_LPM_OFFSET;
+ ccm_clpcr |= 0x3 << MXC_CCM_CLPCR_STBY_COUNT_OFFSET;
+ ccm_clpcr |= MXC_CCM_CLPCR_VSTBY;
+ ccm_clpcr |= MXC_CCM_CLPCR_SBYOS;
+ stop_mode = 1;
+ }
+ arm_srpgcr |= MXC_SRPGCR_PCR;
+
+ if (tzic_enable_wake(1) != 0)
+ return;
+ break;
+ case STOP_POWER_ON:
+ ccm_clpcr |= 0x2 << MXC_CCM_CLPCR_LPM_OFFSET;
+ break;
+ default:
+ printk(KERN_WARNING "UNKNOWN cpu power mode: %d\n", mode);
+ return;
+ }
+
+ __raw_writel(plat_lpc, MXC_CORTEXA8_PLAT_LPC);
+ __raw_writel(ccm_clpcr, MXC_CCM_CLPCR);
+ __raw_writel(arm_srpgcr, MXC_SRPG_ARM_SRPGCR);
+
+ /* Enable NEON SRPG for all but MX50TO1.0. */
+ if (mx50_revision() != IMX_CHIP_REVISION_1_0)
+ __raw_writel(arm_srpgcr, MXC_SRPG_NEON_SRPGCR);
+
+ if (stop_mode) {
+ empgc0 |= MXC_SRPGCR_PCR;
+ empgc1 |= MXC_SRPGCR_PCR;
+
+ __raw_writel(empgc0, MXC_SRPG_EMPGC0_SRPGCR);
+ __raw_writel(empgc1, MXC_SRPG_EMPGC1_SRPGCR);
+ }
+}