mfd: watchdog: iTCO_wdt: Expose watchdog properties using platform data

Intel Sunrisepoint (Skylake PCH) has the iTCO watchdog accessible across
the SMBus, unlike previous generations of PCH/ICH where it was on the
LPC bus. Because it's on the SMBus, it doesn't make sense to pass around
a 'struct lpc_ich_info', and leaking the type of bus into the iTCO
watchdog driver is kind of backwards anyway.

This change introduces a new 'struct itco_wdt_platform_data' for use
inside the iTCO watchdog driver and by the upcoming Intel Sunrisepoint
code, which neatly avoids having to include lpc_ich headers in the i801
i2c driver.

This change is overdue because lpc_ich_info has already found its way
into other TCO watchdog users, notably the intel_pmc_ipc driver where
the watchdog actually isn't on the LPC bus as far as I can see.

A simple translation layer is provided for converting from the existing
'struct lpc_ich_info' inside the lpc_ich mfd driver.

Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Acked-by: Darren Hart <dvhart@linux.intel.com> [drivers/x86 refactoring]
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

1 files changed, 29 insertions, 3 deletions

diff --git a/drivers/mfd/lpc_ich.c b/drivers/mfd/lpc_ich.c
index 8de34398abc0..c5a9a08b5dfb 100644
--- a/drivers/mfd/lpc_ich.c
+++ b/drivers/mfd/lpc_ich.c
@@ -66,6 +66,7 @@
 #include <linux/pci.h>
 #include <linux/mfd/core.h>
 #include <linux/mfd/lpc_ich.h>
+#include <linux/platform_data/itco_wdt.h>
 
 #define ACPIBASE                0x40
 #define ACPIBASE_GPE_OFF        0x28
@@ -835,9 +836,31 @@ static void lpc_ich_enable_pmc_space(struct pci_dev *dev)
         priv->actrl_pbase_save = reg_save;
 }
 
-static void lpc_ich_finalize_cell(struct pci_dev *dev, struct mfd_cell *cell)
+static int lpc_ich_finalize_wdt_cell(struct pci_dev *dev)
 {
+        struct itco_wdt_platform_data *pdata;
         struct lpc_ich_priv *priv = pci_get_drvdata(dev);
+        struct lpc_ich_info *info;
+        struct mfd_cell *cell = &lpc_ich_cells[LPC_WDT];
+
+        pdata = devm_kzalloc(&dev->dev, sizeof(*pdata), GFP_KERNEL);
+        if (!pdata)
+                return -ENOMEM;
+
+        info = &lpc_chipset_info[priv->chipset];
+
+        pdata->version = info->iTCO_version;
+        strlcpy(pdata->name, info->name, sizeof(pdata->name));
+
+        cell->platform_data = pdata;
+        cell->pdata_size = sizeof(*pdata);
+        return 0;
+}
+
+static void lpc_ich_finalize_gpio_cell(struct pci_dev *dev)
+{
+        struct lpc_ich_priv *priv = pci_get_drvdata(dev);
+        struct mfd_cell *cell = &lpc_ich_cells[LPC_GPIO];
 
         cell->platform_data = &lpc_chipset_info[priv->chipset];
         cell->pdata_size = sizeof(struct lpc_ich_info);
@@ -933,7 +956,7 @@ gpe0_done:
         lpc_chipset_info[priv->chipset].use_gpio = ret;
         lpc_ich_enable_gpio_space(dev);
 
-        lpc_ich_finalize_cell(dev, &lpc_ich_cells[LPC_GPIO]);
+        lpc_ich_finalize_gpio_cell(dev);
         ret = mfd_add_devices(&dev->dev, PLATFORM_DEVID_AUTO,
                               &lpc_ich_cells[LPC_GPIO], 1, NULL, 0, NULL);
 
@@ -1007,7 +1030,10 @@ static int lpc_ich_init_wdt(struct pci_dev *dev)
                 res->end = base_addr + ACPIBASE_PMC_END;
         }
 
-        lpc_ich_finalize_cell(dev, &lpc_ich_cells[LPC_WDT]);
+        ret = lpc_ich_finalize_wdt_cell(dev);
+        if (ret)
+                goto wdt_done;
+
         ret = mfd_add_devices(&dev->dev, PLATFORM_DEVID_AUTO,
                               &lpc_ich_cells[LPC_WDT], 1, NULL, 0, NULL);