sh: mach-sdk7786: pm_power_off support.

This wires up power-off support for the SDK7786 board.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

arch/sh/boards/mach-sdk7786/setup.c

@@ -165,6 +165,19 @@ static void sdk7786_restart(char *cmd)
 	fpga_write_reg(0xa5a5, SRSTR);
 }
 
+static void sdk7786_power_off(void)
+{
+	fpga_write_reg(fpga_read_reg(PWRCR) | PWRCR_PDWNREQ, PWRCR);
+
+	/*
+	 * It can take up to 20us for the R8C to do its job, back off and
+	 * wait a bit until we've been shut off. Even though newer FPGA
+	 * versions don't set the ACK bit, the latency issue remains.
+	 */
+	while ((fpga_read_reg(PWRCR) & PWRCR_PDWNACK) == 0)
+		cpu_sleep();
+}
+
 /* Initialize the board */
 static void __init sdk7786_setup(char **cmdline_p)
 {
@@ -175,6 +188,7 @@ static void __init sdk7786_setup(char **cmdline_p)
 	pr_info("\tPCB revision:\t%d\n", fpga_read_reg(PCBRR) & 0xf);
 
 	machine_ops.restart = sdk7786_restart;
+	pm_power_off = sdk7786_power_off;
 }
 
 /*

arch/sh/include/mach-sdk7786/mach/fpga.h

@@ -42,6 +42,15 @@
 #define  SCBR_I2CCEN	BIT(1)	/* CPU I2C master enable */
 
 #define PWRCR		0x1a0
+#define  PWRCR_SCISEL0	BIT(0)
+#define  PWRCR_SCISEL1	BIT(1)
+#define  PWRCR_SCIEN	BIT(2)	/* Serial port enable */
+#define  PWRCR_PDWNACK	BIT(5)	/* Power down acknowledge */
+#define  PWRCR_PDWNREQ	BIT(7)	/* Power down request */
+#define  PWRCR_INT2	BIT(11)	/* INT2 connection to power manager */
+#define  PWRCR_BUPINIT	BIT(13)	/* DDR backup initialize */
+#define  PWRCR_BKPRST	BIT(15) /* Backup power reset */
+
 #define SPCBR		0x1b0
 #define SPICR		0x1c0
 #define SPIDR		0x1d0