superio/nuvoton/npcd378: Add PSU fan control

Implement method to access the SuperIO's harware monitor (HWM) IO space.
Set the PSU fan using a new CMOS option psu_fan_lvl. Add the CMOS option
to all board that use NPCD378. In case no CMOS is set use the default
fan level 3.

The HWM space can be written to at any time, but the SuperIO has to be
notified that a write is ongoing. After clearing the write-lock bit all
changes are applied at once.

Tested on HP Compaq 8200 SFF.

Change-Id: I56ce7ad1df88638589a577b8a09d5d775557887b
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/26050
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 63 insertions, 1 deletions

diff --git a/src/superio/nuvoton/npcd378/superio.c b/src/superio/nuvoton/npcd378/superio.c
index d468884c82..013225de32 100644
--- a/src/superio/nuvoton/npcd378/superio.c
+++ b/src/superio/nuvoton/npcd378/superio.c
@@ -18,24 +18,86 @@
  */
 
 #include <arch/io.h>
+#include <console/console.h>
 #include <device/device.h>
 #include <device/pnp.h>
+#include <option.h>
 #include <pc80/keyboard.h>
 #include <stdlib.h>
 #include <superio/conf_mode.h>
 
 #include "npcd378.h"
 
+uint8_t npcd378_hwm_read(const uint16_t iobase, const uint16_t reg)
+{
+	outb((reg >> 8) & 0xf, iobase + 0xff);
+	uint8_t reg8 = inb(iobase + (reg & 0xff));
+	if (reg8 == 0xff)
+		reg8 = inb(iobase + (reg & 0xff));
+
+	outb(0, iobase + 0xff);
+	return reg8;
+}
+
+void npcd378_hwm_write(const uint16_t iobase, const uint16_t reg,
+		       const uint8_t val)
+{
+	outb((reg >> 8) & 0xf, iobase + 0xff);
+	outb(val, iobase + (reg & 0xff));
+
+	outb(0, iobase + 0xff);
+}
+
+void npcd378_hwm_write_start(const uint16_t iobase)
+{
+	u8 reg8 = npcd378_hwm_read(iobase, NPCD837_HWM_WRITE_LOCK_CTRL);
+	reg8 &= ~NPCD837_HWM_WRITE_LOCK_BIT;
+	npcd378_hwm_write(iobase, NPCD837_HWM_WRITE_LOCK_CTRL, reg8);
+}
+
+void npcd378_hwm_write_finished(const uint16_t iobase)
+{
+	u8 reg8 = npcd378_hwm_read(iobase, NPCD837_HWM_WRITE_LOCK_CTRL);
+	reg8 |= NPCD837_HWM_WRITE_LOCK_BIT;
+	npcd378_hwm_write(iobase, NPCD837_HWM_WRITE_LOCK_CTRL, reg8);
+}
+
 static void npcd378_init(struct device *dev)
 {
+	struct resource *res;
+	uint8_t pwm, fan_lvl;
+
 	if (!dev->enabled)
 		return;
 
 	switch (dev->path.pnp.device) {
-	/* TODO: Might potentially need code for HWM or FDC etc. */
+	/* TODO: Might potentially need code for FDC etc. */
 	case NPCD378_KBC:
 		pc_keyboard_init(PROBE_AUX_DEVICE);
 		break;
+	case NPCD378_HWM:
+		res = find_resource(dev, PNP_IDX_IO0);
+		if (!res || !res->base) {
+			printk(BIOS_ERR, "NPCD378: LDN%u IOBASE not set.\n",
+			       NPCD378_HWM);
+			break;
+		}
+
+		npcd378_hwm_write_start(res->base);
+
+		if (!get_option(&fan_lvl, "psu_fan_lvl") || fan_lvl > 7)
+			fan_lvl = 3;
+
+		pwm = NPCD378_HWM_PSU_FAN_MIN +
+		    (NPCD378_HWM_PSU_FAN_MAX - NPCD378_HWM_PSU_FAN_MIN) *
+		    fan_lvl / 7;
+
+		/* Set PSU fan PWM lvl */
+		npcd378_hwm_write(res->base, NPCD378_HWM_PSU_FAN_PWM_CTRL, pwm);
+		printk(BIOS_INFO, "NPCD378: PSU fan PWM 0x%02x\n", pwm);
+
+		npcd378_hwm_write_finished(res->base);
+		break;
 	}
 }