platform/x86: intel_pmc_ipc: Convert to MFD

This driver only creates a bunch of platform devices sharing resources
belonging to the PMC device. This is pretty much what MFD subsystem is
for so move the driver there, renaming it to intel_pmc_bxt.c which
should be more clear what it is.

MFD subsystem provides nice helper APIs for subdevice creation so
convert the driver to use those. Unfortunately the ACPI device includes
separate resources for most of the subdevices so we cannot simply call
mfd_add_devices() to create all of them but instead we need to call it
separately for each device.

The new MFD driver continues to expose two sysfs attributes that allow
userspace to send IPC commands to the PMC/SCU to avoid breaking any
existing applications that may use these. Generally this is bad idea so
document this in the ABI documentation.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

1 files changed, 19 insertions, 6 deletions

diff --git a/drivers/watchdog/iTCO_wdt.c b/drivers/watchdog/iTCO_wdt.c
index e707c4797f76..a370a185a41c 100644
--- a/drivers/watchdog/iTCO_wdt.c
+++ b/drivers/watchdog/iTCO_wdt.c
@@ -64,6 +64,7 @@
 #include <linux/uaccess.h>		/* For copy_to_user/put_user/... */
 #include <linux/io.h>			/* For inb/outb/... */
 #include <linux/platform_data/itco_wdt.h>
+#include <linux/mfd/intel_pmc_bxt.h>
 
 #include "iTCO_vendor.h"
 
@@ -233,12 +234,24 @@ static int update_no_reboot_bit_cnt(void *priv, bool set)
 	return val != newval ? -EIO : 0;
 }
 
+static int update_no_reboot_bit_pmc(void *priv, bool set)
+{
+	struct intel_pmc_dev *pmc = priv;
+	u32 bits = PMC_CFG_NO_REBOOT_EN;
+	u32 value = set ? bits : 0;
+
+	return intel_pmc_gcr_update(pmc, PMC_GCR_PMC_CFG_REG, bits, value);
+}
+
 static void iTCO_wdt_no_reboot_bit_setup(struct iTCO_wdt_private *p,
-		struct itco_wdt_platform_data *pdata)
+					 struct platform_device *pdev,
+					 struct itco_wdt_platform_data *pdata)
 {
-	if (pdata->update_no_reboot_bit) {
-		p->update_no_reboot_bit = pdata->update_no_reboot_bit;
-		p->no_reboot_priv = pdata->no_reboot_priv;
+	if (pdata->no_reboot_use_pmc) {
+		struct intel_pmc_dev *pmc = dev_get_drvdata(pdev->dev.parent);
+
+		p->update_no_reboot_bit = update_no_reboot_bit_pmc;
+		p->no_reboot_priv = pmc;
 		return;
 	}
 
@@ -478,14 +491,14 @@ static int iTCO_wdt_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
-	iTCO_wdt_no_reboot_bit_setup(p, pdata);
+	iTCO_wdt_no_reboot_bit_setup(p, pdev, pdata);
 
 	/*
 	 * Get the Memory-Mapped GCS or PMC register, we need it for the
 	 * NO_REBOOT flag (TCO v2 and v3).
 	 */
 	if (p->iTCO_version >= 2 && p->iTCO_version < 6 &&
-	    !pdata->update_no_reboot_bit) {
+	    !pdata->no_reboot_use_pmc) {
 		p->gcs_pmc_res = platform_get_resource(pdev,
 						       IORESOURCE_MEM,
 						       ICH_RES_MEM_GCS_PMC);