MIPS: Loongson-3: Add chipset ACPI platform driver

This add south-bridge (SB700/SB710/SB800 chipset) ACPI platform driver
for Loongson-3. This will be used by EC (Embedded Controller, used by
laptops) driver and STR (Suspend To RAM).

[ralf@linux-mips.org: Fix build error if !CONFIG_CPU_LOONGSON3.  Build
doesn't like it if no obj-* variable is defined at all in a Makefile.
Obviously this has not been tested on other platforms.]

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/9619/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

3 files changed, 155 insertions, 0 deletions

diff --git a/drivers/platform/mips/Kconfig b/drivers/platform/mips/Kconfig
index b3ae30a..125e569 100644
--- a/drivers/platform/mips/Kconfig
+++ b/drivers/platform/mips/Kconfig
@@ -15,6 +15,10 @@ menuconfig MIPS_PLATFORM_DEVICES
 
 if MIPS_PLATFORM_DEVICES
 
+config MIPS_ACPI
+	bool
+	default y if LOONGSON_MACH3X
+
 config CPU_HWMON
 	tristate "Loongson CPU HWMon Driver"
 	depends on LOONGSON_MACH3X
diff --git a/drivers/platform/mips/Makefile b/drivers/platform/mips/Makefile
index 8dfd039..4341284 100644
--- a/drivers/platform/mips/Makefile
+++ b/drivers/platform/mips/Makefile
@@ -1 +1,2 @@
+obj-$(CONFIG_MIPS_ACPI) += acpi_init.o
 obj-$(CONFIG_CPU_HWMON) += cpu_hwmon.o
diff --git a/drivers/platform/mips/acpi_init.c b/drivers/platform/mips/acpi_init.c
new file mode 100644
index 0000000..dbdad79
--- /dev/null
+++ b/drivers/platform/mips/acpi_init.c
@@ -0,0 +1,150 @@
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/export.h>
+
+#define SBX00_ACPI_IO_BASE 0x800
+#define SBX00_ACPI_IO_SIZE 0x100
+
+#define ACPI_PM_EVT_BLK         (SBX00_ACPI_IO_BASE + 0x00) /* 4 bytes */
+#define ACPI_PM_CNT_BLK         (SBX00_ACPI_IO_BASE + 0x04) /* 2 bytes */
+#define ACPI_PMA_CNT_BLK        (SBX00_ACPI_IO_BASE + 0x0F) /* 1 byte */
+#define ACPI_PM_TMR_BLK         (SBX00_ACPI_IO_BASE + 0x18) /* 4 bytes */
+#define ACPI_GPE0_BLK           (SBX00_ACPI_IO_BASE + 0x10) /* 8 bytes */
+#define ACPI_END                (SBX00_ACPI_IO_BASE + 0x80)
+
+#define PM_INDEX        0xCD6
+#define PM_DATA         0xCD7
+#define PM2_INDEX       0xCD0
+#define PM2_DATA        0xCD1
+
+/*
+ * SCI interrupt need acpi space, allocate here
+ */
+
+static int __init register_acpi_resource(void)
+{
+	request_region(SBX00_ACPI_IO_BASE, SBX00_ACPI_IO_SIZE, "acpi");
+	return 0;
+}
+
+static void pmio_write_index(u16 index, u8 reg, u8 value)
+{
+	outb(reg, index);
+	outb(value, index + 1);
+}
+
+static u8 pmio_read_index(u16 index, u8 reg)
+{
+	outb(reg, index);
+	return inb(index + 1);
+}
+
+void pm_iowrite(u8 reg, u8 value)
+{
+	pmio_write_index(PM_INDEX, reg, value);
+}
+EXPORT_SYMBOL(pm_iowrite);
+
+u8 pm_ioread(u8 reg)
+{
+	return pmio_read_index(PM_INDEX, reg);
+}
+EXPORT_SYMBOL(pm_ioread);
+
+void pm2_iowrite(u8 reg, u8 value)
+{
+	pmio_write_index(PM2_INDEX, reg, value);
+}
+EXPORT_SYMBOL(pm2_iowrite);
+
+u8 pm2_ioread(u8 reg)
+{
+	return pmio_read_index(PM2_INDEX, reg);
+}
+EXPORT_SYMBOL(pm2_ioread);
+
+static void acpi_hw_clear_status(void)
+{
+	u16 value;
+
+	/* PMStatus: Clear WakeStatus/PwrBtnStatus */
+	value = inw(ACPI_PM_EVT_BLK);
+	value |= (1 << 8 | 1 << 15);
+	outw(value, ACPI_PM_EVT_BLK);
+
+	/* GPEStatus: Clear all generated events */
+	outl(inl(ACPI_GPE0_BLK), ACPI_GPE0_BLK);
+}
+
+void acpi_registers_setup(void)
+{
+	u32 value;
+
+	/* PM Status Base */
+	pm_iowrite(0x20, ACPI_PM_EVT_BLK & 0xff);
+	pm_iowrite(0x21, ACPI_PM_EVT_BLK >> 8);
+
+	/* PM Control Base */
+	pm_iowrite(0x22, ACPI_PM_CNT_BLK & 0xff);
+	pm_iowrite(0x23, ACPI_PM_CNT_BLK >> 8);
+
+	/* GPM Base */
+	pm_iowrite(0x28, ACPI_GPE0_BLK & 0xff);
+	pm_iowrite(0x29, ACPI_GPE0_BLK >> 8);
+
+	/* ACPI End */
+	pm_iowrite(0x2e, ACPI_END & 0xff);
+	pm_iowrite(0x2f, ACPI_END >> 8);
+
+	/* IO Decode: When AcpiDecodeEnable set, South-Bridge uses the contents
+	 * of the PM registers at index 0x20~0x2B to decode ACPI I/O address. */
+	pm_iowrite(0x0e, 1 << 3);
+
+	/* SCI_EN set */
+	outw(1, ACPI_PM_CNT_BLK);
+
+	/* Enable to generate SCI */
+	pm_iowrite(0x10, pm_ioread(0x10) | 1);
+
+	/* GPM3/GPM9 enable */
+	value = inl(ACPI_GPE0_BLK + 4);
+	outl(value | (1 << 14) | (1 << 22), ACPI_GPE0_BLK + 4);
+
+	/* Set GPM9 as input */
+	pm_iowrite(0x8d, pm_ioread(0x8d) & (~(1 << 1)));
+
+	/* Set GPM9 as non-output */
+	pm_iowrite(0x94, pm_ioread(0x94) | (1 << 3));
+
+	/* GPM3 config ACPI trigger SCIOUT */
+	pm_iowrite(0x33, pm_ioread(0x33) & (~(3 << 4)));
+
+	/* GPM9 config ACPI trigger SCIOUT */
+	pm_iowrite(0x3d, pm_ioread(0x3d) & (~(3 << 2)));
+
+	/* GPM3 config falling edge trigger */
+	pm_iowrite(0x37, pm_ioread(0x37) & (~(1 << 6)));
+
+	/* No wait for STPGNT# in ACPI Sx state */
+	pm_iowrite(0x7c, pm_ioread(0x7c) | (1 << 6));
+
+	/* Set GPM3 pull-down enable */
+	value = pm2_ioread(0xf6);
+	value |= ((1 << 7) | (1 << 3));
+	pm2_iowrite(0xf6, value);
+
+	/* Set GPM9 pull-down enable */
+	value = pm2_ioread(0xf8);
+	value |= ((1 << 5) | (1 << 1));
+	pm2_iowrite(0xf8, value);
+}
+
+int __init sbx00_acpi_init(void)
+{
+	register_acpi_resource();
+	acpi_registers_setup();
+	acpi_hw_clear_status();
+
+	return 0;
+}