x86/platform/intel-mid: Implement power off sequence

Tell SCU that we are about powering off the device.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160907123955.21228-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/intel-mid.h

@@ -18,6 +18,8 @@
 extern int intel_mid_pci_init(void);
 extern int intel_mid_pci_set_power_state(struct pci_dev *pdev, pci_power_t state);
 
+extern void intel_mid_pwr_power_off(void);
+
 #define INTEL_MID_PWR_LSS_OFFSET	4
 #define INTEL_MID_PWR_LSS_TYPE		(1 << 7)
 

arch/x86/include/asm/intel_scu_ipc.h

@@ -3,6 +3,8 @@
 
 #include <linux/notifier.h>
 
+#define IPCMSG_COLD_OFF		0x80	/* Only for Tangier */
+
 #define IPCMSG_WARM_RESET	0xF0
 #define IPCMSG_COLD_RESET	0xF1
 #define IPCMSG_SOFT_RESET	0xF2

arch/x86/platform/intel-mid/intel-mid.c

@@ -70,6 +70,11 @@ EXPORT_SYMBOL_GPL(__intel_mid_cpu_chip);
 
 static void intel_mid_power_off(void)
 {
+	/* Shut down South Complex via PWRMU */
+	intel_mid_pwr_power_off();
+
+	/* Only for Tangier, the rest will ignore this command */
+	intel_scu_ipc_simple_command(IPCMSG_COLD_OFF, 1);
 };
 
 static void intel_mid_reboot(void)

arch/x86/platform/intel-mid/pwr.c

@@ -48,7 +48,15 @@
 #define PM_CMD_CM_IMMEDIATE	(1 << 9)
 #define PM_CMD_CM_DELAY		(2 << 9)
 #define PM_CMD_CM_TRIGGER	(3 << 9)
-#define PM_CMD_D3cold		(1 << 21)
+
+/* System states */
+#define PM_CMD_SYS_STATE_S5	(5 << 16)
+
+/* Trigger variants */
+#define PM_CMD_CFG_TRIGGER_NC	(3 << 19)
+
+/* Message to wait for TRIGGER_NC case */
+#define TRIGGER_NC_MSG_2	(2 << 22)
 
 /* List of commands */
 #define CMD_SET_CFG		0x01
@@ -264,6 +272,20 @@ int intel_mid_pci_set_power_state(struct pci_dev *pdev, pci_power_t state)
 }
 EXPORT_SYMBOL_GPL(intel_mid_pci_set_power_state);
 
+void intel_mid_pwr_power_off(void)
+{
+	struct mid_pwr *pwr = midpwr;
+	u32 cmd = PM_CMD_SYS_STATE_S5 |
+		  PM_CMD_CMD(CMD_SET_CFG) |
+		  PM_CMD_CM_TRIGGER |
+		  PM_CMD_CFG_TRIGGER_NC |
+		  TRIGGER_NC_MSG_2;
+
+	/* Send command to SCU */
+	writel(cmd, pwr->regs + PM_CMD);
+	mid_pwr_wait(pwr);
+}
+
 int intel_mid_pwr_get_lss_id(struct pci_dev *pdev)
 {
 	int vndr;