@@ -19,6 +19,8 @@
#include <linux/smp.h>
#include <asm/cacheflush.h>
+#include <asm/hardware/gic.h>
+
#include <mach/omap4-common.h>
#include <mach/omap-wakeupgen.h>
@@ -57,6 +59,7 @@ void platform_cpu_die(unsigned int cpu)
* clear all interrupt wakeup sources
*/
omap_wakeupgen_irqmask_all(cpu, 1);
+ gic_cpu_disable();
omap4_enter_lowpower(cpu, PWRDM_POWER_OFF);
this_cpu = hard_smp_processor_id();
if (omap_read_auxcoreboot0() == this_cpu) {
@@ -64,6 +67,7 @@ void platform_cpu_die(unsigned int cpu)
* OK, proper wakeup, we're done
*/
omap_wakeupgen_irqmask_all(this_cpu, 0);
+ gic_cpu_enable();
/* Restore clockdomain to hardware supervised */
clkdm_allow_idle(cpu1_clkdm);
@@ -47,6 +47,8 @@
#include <asm/tlbflush.h>
#include <asm/smp_scu.h>
#include <asm/system.h>
+#include <asm/irq.h>
+#include <asm/hardware/gic.h>
#include <plat/omap44xx.h>
#include <mach/omap4-common.h>
@@ -57,13 +59,41 @@
#ifdef CONFIG_SMP
+#define GIC_MASK_ALL 0x0
+#define GIC_ISR_NON_SECURE 0xffffffff
+#define SPI_ENABLE_SET_OFFSET 0x04
+#define PPI_PRI_OFFSET 0x1c
+#define SPI_PRI_OFFSET 0x20
+#define SPI_TARGET_OFFSET 0x20
+#define SPI_CONFIG_OFFSET 0x20
+
+/* GIC save SAR bank base */
+static struct powerdomain *mpuss_pd;
+
+/* Variables to store maximum spi(Shared Peripheral Interrupts) registers. */
+static u32 max_spi_irq, max_spi_reg;
+
struct omap4_cpu_pm_info {
struct powerdomain *pwrdm;
void __iomem *scu_sar_addr;
};
+static void __iomem *gic_dist_base;
+static void __iomem *sar_base;
+
static DEFINE_PER_CPU(struct omap4_cpu_pm_info, omap4_pm_info);
+/* Helper functions */
+static inline void sar_writel(u32 val, u32 offset, u8 idx)
+{
+ __raw_writel(val, sar_base + offset + 4 * idx);
+}
+
+static inline u32 gic_readl(u32 offset, u8 idx)
+{
+ return __raw_readl(gic_dist_base + offset + 4 * idx);
+}
+
/*
* Set the CPUx powerdomain's previous power state
*/
@@ -121,6 +151,85 @@ static void scu_pwrst_prepare(unsigned int cpu_id, unsigned int cpu_state)
}
/*
+ * Save GIC context in SAR RAM. Restore is done by ROM code
+ * GIC is lost only when MPU hits OSWR or OFF. It consists
+ * of a distributor and a per-CPU interface module. The GIC
+ * save restore is optimised to save only necessary registers.
+ */
+static void gic_save_context(void)
+{
+ u8 i;
+ u32 val;
+
+ /*
+ * Interrupt Clear Enable registers are inverse of set enable
+ * and hence not needed to be saved. ROM code programs it
+ * based on Set Enable register values.
+ */
+
+ /* Save CPU 0 Interrupt Set Enable register */
+ val = gic_readl(GIC_DIST_ENABLE_SET, 0);
+ sar_writel(val, ICDISER_CPU0_OFFSET, 0);
+
+ /* Disable interrupts on CPU1 */
+ sar_writel(GIC_MASK_ALL, ICDISER_CPU1_OFFSET, 0);
+
+ /* Save all SPI Set Enable register */
+ for (i = 0; i < max_spi_reg; i++) {
+ val = gic_readl(GIC_DIST_ENABLE_SET + SPI_ENABLE_SET_OFFSET, i);
+ sar_writel(val, ICDISER_SPI_OFFSET, i);
+ }
+
+ /*
+ * Interrupt Priority Registers
+ * Secure sw accesses, last 5 bits of the 8 bits (bit[7:3] are used)
+ * Non-Secure sw accesses, last 4 bits (i.e. bits[7:4] are used)
+ * But the Secure Bits[7:3] are shifted by 1 in Non-Secure access.
+ * Secure (bits[7:3] << 1)== Non Secure bits[7:4]
+ * Hence right shift the value by 1 while saving the priority
+ */
+
+ /* Save SGI priority registers (Software Generated Interrupt) */
+ for (i = 0; i < 4; i++) {
+ val = gic_readl(GIC_DIST_PRI, i);
+
+ /* Save the priority bits of the Interrupts */
+ sar_writel(val >> 0x1, ICDIPR_SFI_CPU0_OFFSET, i);
+
+ /* Disable the interrupts on CPU1 */
+ sar_writel(GIC_MASK_ALL, ICDIPR_SFI_CPU1_OFFSET, i);
+ }
+
+ /* Save PPI priority registers (Private Peripheral Intterupts) */
+ val = gic_readl(GIC_DIST_PRI + PPI_PRI_OFFSET, 0);
+ sar_writel(val >> 0x1, ICDIPR_PPI_CPU0_OFFSET, 0);
+ sar_writel(GIC_MASK_ALL, ICDIPR_PPI_CPU1_OFFSET, 0);
+
+ /* SPI priority registers - 4 interrupts/register */
+ for (i = 0; i < (max_spi_irq / 4); i++) {
+ val = gic_readl((GIC_DIST_PRI + SPI_PRI_OFFSET), i);
+ sar_writel(val >> 0x1, ICDIPR_SPI_OFFSET, i);
+ }
+
+ /* SPI Interrupt Target registers - 4 interrupts/register */
+ for (i = 0; i < (max_spi_irq / 4); i++) {
+ val = gic_readl((GIC_DIST_TARGET + SPI_TARGET_OFFSET), i);
+ sar_writel(val, ICDIPTR_SPI_OFFSET, i);
+ }
+
+ /* SPI Interrupt Congigeration eegisters- 16 interrupts/register */
+ for (i = 0; i < (max_spi_irq / 16); i++) {
+ val = gic_readl((GIC_DIST_CONFIG + SPI_CONFIG_OFFSET), i);
+ sar_writel(val, ICDICFR_OFFSET, i);
+ }
+
+ /* Set the Backup Bit Mask status for GIC */
+ val = __raw_readl(sar_base + SAR_BACKUP_STATUS_OFFSET);
+ val |= (SAR_BACKUP_STATUS_GIC_CPU0 | SAR_BACKUP_STATUS_GIC_CPU1);
+ __raw_writel(val, sar_base + SAR_BACKUP_STATUS_OFFSET);
+}
+
+/*
* OMAP4 MPUSS Low Power Entry Function
*
* The purpose of this function is to manage low power programming
@@ -128,11 +237,25 @@ static void scu_pwrst_prepare(unsigned int cpu_id, unsigned int cpu_state)
* Paramenters:
* cpu : CPU ID
* power_state: Targetted Low power state.
+ *
+ * MPUSS Low power states
+ * The basic rule is that the MPUSS power domain must be at the higher or
+ * equal power state (state that consume more power) than the higher of the
+ * two CPUs. For example, it is illegal for system power to be OFF, while
+ * the power of one or both of the CPU is DORMANT. When an illegal state is
+ * entered, then the hardware behavior is unpredictable.
+ *
+ * MPUSS state for the context save
+ * save_state =
+ * 0 - Nothing lost and no need to save: MPUSS INACTIVE
+ * 1 - CPUx L1 and logic lost: MPUSS CSWR
+ * 2 - CPUx L1 and logic lost + GIC lost: MPUSS OSWR
+ * 3 - CPUx L1 and logic lost + GIC + L2 lost: MPUSS OFF
*/
int omap4_enter_lowpower(unsigned int cpu, unsigned int power_state)
{
unsigned int save_state = 0;
- unsigned int wakeup_cpu = hard_smp_processor_id();
+ unsigned int wakeup_cpu;
if ((cpu >= NR_CPUS) || (omap_rev() == OMAP4430_REV_ES1_0))
goto ret;
@@ -157,6 +280,23 @@ int omap4_enter_lowpower(unsigned int cpu, unsigned int power_state)
goto ret;
}
+ /*
+ * MPUSS book keeping should be executed by master
+ * CPU only which is also the last CPU to go down.
+ */
+ if (cpu)
+ goto cpu_prepare;
+
+ /*
+ * Check MPUSS next state and save GIC if needed
+ * GIC lost during MPU OFF and OSWR
+ */
+ if (pwrdm_read_next_pwrst(mpuss_pd) == PWRDM_POWER_OFF) {
+ gic_save_context();
+ save_state = 3;
+ }
+
+cpu_prepare:
clear_cpu_prev_pwrst(cpu);
set_cpu_next_pwrst(cpu, power_state);
scu_pwrst_prepare(cpu, power_state);
@@ -177,6 +317,19 @@ int omap4_enter_lowpower(unsigned int cpu, unsigned int power_state)
wakeup_cpu = hard_smp_processor_id();
set_cpu_next_pwrst(wakeup_cpu, PWRDM_POWER_ON);
+ /* If !master cpu return to hotplug-path */
+ if (wakeup_cpu)
+ goto ret;
+
+ /* Check MPUSS previous power state and enable GIC if needed */
+ if (pwrdm_read_prev_pwrst(mpuss_pd) == PWRDM_POWER_OFF) {
+ /* Clear SAR BACKUP status */
+ __raw_writel(0x0, sar_base + SAR_BACKUP_STATUS_OFFSET);
+ /* Enable GIC distributor and inteface on CPU0*/
+ gic_cpu_enable();
+ gic_dist_enable();
+ }
+
ret:
return 0;
}
@@ -187,7 +340,11 @@ ret:
int __init omap4_mpuss_init(void)
{
struct omap4_cpu_pm_info *pm_info;
- void __iomem *sar_ram_base = omap4_get_sar_ram_base();
+ u8 i;
+
+ /* Get GIC and SAR RAM base addresses */
+ sar_base = omap4_get_sar_ram_base();
+ gic_dist_base = omap4_get_gic_dist_base();
if (omap_rev() == OMAP4430_REV_ES1_0) {
WARN(1, "Power Management not supported on OMAP4430 ES1.0\n");
@@ -196,7 +353,7 @@ int __init omap4_mpuss_init(void)
/* Initilaise per CPU PM information */
pm_info = &per_cpu(omap4_pm_info, 0x0);
- pm_info->scu_sar_addr = sar_ram_base + SCU_OFFSET0;
+ pm_info->scu_sar_addr = sar_base + SCU_OFFSET0;
pm_info->pwrdm = pwrdm_lookup("cpu0_pwrdm");
if (!pm_info->pwrdm) {
pr_err("Lookup failed for CPU0 pwrdm\n");
@@ -210,7 +367,7 @@ int __init omap4_mpuss_init(void)
pwrdm_set_next_pwrst(pm_info->pwrdm, PWRDM_POWER_ON);
pm_info = &per_cpu(omap4_pm_info, 0x1);
- pm_info->scu_sar_addr = sar_ram_base + SCU_OFFSET1;
+ pm_info->scu_sar_addr = sar_base + SCU_OFFSET1;
pm_info->pwrdm = pwrdm_lookup("cpu1_pwrdm");
if (!pm_info->pwrdm) {
pr_err("Lookup failed for CPU1 pwrdm\n");
@@ -229,9 +386,35 @@ int __init omap4_mpuss_init(void)
* is fixed so programit in init itself.
*/
__raw_writel(virt_to_phys(omap4_cpu_resume),
- sar_ram_base + CPU1_WAKEUP_NS_PA_ADDR_OFFSET);
+ sar_base + CPU1_WAKEUP_NS_PA_ADDR_OFFSET);
__raw_writel(virt_to_phys(omap4_cpu_resume),
- sar_ram_base + CPU0_WAKEUP_NS_PA_ADDR_OFFSET);
+ sar_base + CPU0_WAKEUP_NS_PA_ADDR_OFFSET);
+
+ mpuss_pd = pwrdm_lookup("mpu_pwrdm");
+ if (!mpuss_pd) {
+ pr_err("Failed to get lookup for MPUSS pwrdm\n");
+ return -ENODEV;
+ }
+
+ /*
+ * Find out how many interrupts are supported.
+ * OMAP4 supports max of 128 SPIs where as GIC can support
+ * up to 1020 interrupt sources. On OMAP4, maximum SPIs are
+ * fused in DIST_CTR bit-fields as 128. Hence the code is safe
+ * from reserved register writes since its well within 1020.
+ */
+ max_spi_reg = __raw_readl(gic_dist_base + GIC_DIST_CTR) & 0x1f;
+ max_spi_irq = max_spi_reg * 32;
+
+ /*
+ * Mark the PPI and SPI interrupts as non-secure.
+ * program the SAR locations for interrupt security registers to
+ * reflect the same.
+ */
+ sar_writel(GIC_ISR_NON_SECURE, ICDISR_CPU0_OFFSET, 0);
+ sar_writel(GIC_ISR_NON_SECURE, ICDISR_CPU1_OFFSET, 0);
+ for (i = 0; i < max_spi_reg; i++)
+ sar_writel(GIC_ISR_NON_SECURE, ICDISR_SPI_OFFSET, i);
return 0;
}
@@ -30,4 +30,24 @@
#define CPU0_WAKEUP_NS_PA_ADDR_OFFSET 0xa04
#define CPU1_WAKEUP_NS_PA_ADDR_OFFSET 0xa08
+/* GIC save restore offset from SAR_BANK3 */
+#define SAR_BACKUP_STATUS_OFFSET (SAR_BANK3_OFFSET + 0x500)
+#define SAR_SECURE_RAM_SIZE_OFFSET (SAR_BANK3_OFFSET + 0x504)
+#define SAR_SECRAM_SAVED_AT_OFFSET (SAR_BANK3_OFFSET + 0x508)
+#define ICDISR_CPU0_OFFSET (SAR_BANK3_OFFSET + 0x50c)
+#define ICDISR_CPU1_OFFSET (SAR_BANK3_OFFSET + 0x510)
+#define ICDISR_SPI_OFFSET (SAR_BANK3_OFFSET + 0x514)
+#define ICDISER_CPU0_OFFSET (SAR_BANK3_OFFSET + 0x524)
+#define ICDISER_CPU1_OFFSET (SAR_BANK3_OFFSET + 0x528)
+#define ICDISER_SPI_OFFSET (SAR_BANK3_OFFSET + 0x52c)
+#define ICDIPR_SFI_CPU0_OFFSET (SAR_BANK3_OFFSET + 0x53c)
+#define ICDIPR_PPI_CPU0_OFFSET (SAR_BANK3_OFFSET + 0x54c)
+#define ICDIPR_SFI_CPU1_OFFSET (SAR_BANK3_OFFSET + 0x550)
+#define ICDIPR_PPI_CPU1_OFFSET (SAR_BANK3_OFFSET + 0x560)
+#define ICDIPR_SPI_OFFSET (SAR_BANK3_OFFSET + 0x564)
+#define ICDIPTR_SPI_OFFSET (SAR_BANK3_OFFSET + 0x5e4)
+#define ICDICFR_OFFSET (SAR_BANK3_OFFSET + 0x664)
+#define SAR_BACKUP_STATUS_GIC_CPU0 0x1
+#define SAR_BACKUP_STATUS_GIC_CPU1 0x2
+
#endif