Re: [PATCH v4 1/3] iTCO_wdt: Expose watchdog properties using platform data

From: Guenter Roeck
Date: Fri Aug 07 2015 - 11:30:51 EST

On 08/06/2015 05:46 AM, Matt Fleming wrote:
From: Matt Fleming <matt.fleming@xxxxxxxxx>

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.

Cc: Peter Tyser <ptyser@xxxxxxxxxxx>
Cc: Samuel Ortiz <sameo@xxxxxxxxxxxxxxx>
Acked-by: Lee Jones <lee.jones@xxxxxxxxxx>
Cc: Wim Van Sebroeck <wim@xxxxxxxxx>
Cc: Zha Qipeng <qipeng.zha@xxxxxxxxx>
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>

Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>

Cc: Jean Delvare <jdelvare@xxxxxxxx>
Acked-by: Darren Hart <dvhart@xxxxxxxxxxxxxxx> [drivers/x86 refactoring]
Signed-off-by: Matt Fleming <matt.fleming@xxxxxxxxx>
---
v4:
- Added Darren's ACK

v3:
- Added Lee's ACK

v2:
- Use lowercase "itco" in all new files and data structures.
- Use devm_kzalloc() to allocate platform data, fixing a memory leak
and saving us from having to free the allocation in error paths
- Move stray Kconfig hunk to PATCH 3 that accidentally snuck into v1
- Swap strcpy() for the safer strlcpy()
- Fix lpc_ich_info user in the intel_pmc_ipc driver that was merged for
v4.2.

drivers/mfd/lpc_ich.c | 32 +++++++++++++++++++++++++++++---
drivers/platform/x86/intel_pmc_ipc.c | 9 ++++-----
drivers/watchdog/iTCO_wdt.c | 11 +++++------
include/linux/mfd/lpc_ich.h | 6 ------
include/linux/platform_data/itco_wdt.h | 19 +++++++++++++++++++
5 files changed, 57 insertions(+), 20 deletions(-)
create mode 100644 include/linux/platform_data/itco_wdt.h

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);

diff --git a/drivers/platform/x86/intel_pmc_ipc.c b/drivers/platform/x86/intel_pmc_ipc.c
index 105cfffe82c6..28b2a12bb26d 100644
--- a/drivers/platform/x86/intel_pmc_ipc.c
+++ b/drivers/platform/x86/intel_pmc_ipc.c
@@ -33,7 +33,7 @@
#include <linux/suspend.h>
#include <linux/acpi.h>
#include <asm/intel_pmc_ipc.h>
-#include <linux/mfd/lpc_ich.h>
+#include <linux/platform_data/itco_wdt.h>

/*
* IPC registers
@@ -473,9 +473,9 @@ static struct resource tco_res[] = {
},
};

-static struct lpc_ich_info tco_info = {
+static struct itco_wdt_platform_data tco_info = {
.name = "Apollo Lake SoC",
- .iTCO_version = 3,
+ .version = 3,
};

static int ipc_create_punit_device(void)
@@ -552,8 +552,7 @@ static int ipc_create_tco_device(void)
goto err;
}

- ret = platform_device_add_data(pdev, &tco_info,
- sizeof(struct lpc_ich_info));
+ ret = platform_device_add_data(pdev, &tco_info, sizeof(tco_info));
if (ret) {
dev_err(ipcdev.dev, "Failed to add tco platform data\n");
goto err;
diff --git a/drivers/watchdog/iTCO_wdt.c b/drivers/watchdog/iTCO_wdt.c
index 3c3fd417ddeb..a94401b2deca 100644
--- a/drivers/watchdog/iTCO_wdt.c
+++ b/drivers/watchdog/iTCO_wdt.c
@@ -66,8 +66,7 @@
#include <linux/spinlock.h> /* For spin_lock/spin_unlock/... */
#include <linux/uaccess.h> /* For copy_to_user/put_user/... */
#include <linux/io.h> /* For inb/outb/... */
-#include <linux/mfd/core.h>
-#include <linux/mfd/lpc_ich.h>
+#include <linux/platform_data/itco_wdt.h>

#include "iTCO_vendor.h"

@@ -418,9 +417,9 @@ static int iTCO_wdt_probe(struct platform_device *dev)
{
int ret = -ENODEV;
unsigned long val32;
- struct lpc_ich_info *ich_info = dev_get_platdata(&dev->dev);
+ struct itco_wdt_platform_data *pdata = dev_get_platdata(&dev->dev);

- if (!ich_info)
+ if (!pdata)
goto out;

spin_lock_init(&iTCO_wdt_private.io_lock);
@@ -435,7 +434,7 @@ static int iTCO_wdt_probe(struct platform_device *dev)
if (!iTCO_wdt_private.smi_res)
goto out;

- iTCO_wdt_private.iTCO_version = ich_info->iTCO_version;
+ iTCO_wdt_private.iTCO_version = pdata->version;
iTCO_wdt_private.dev = dev;
iTCO_wdt_private.pdev = to_pci_dev(dev->dev.parent);

@@ -501,7 +500,7 @@ static int iTCO_wdt_probe(struct platform_device *dev)
}

pr_info("Found a %s TCO device (Version=%d, TCOBASE=0x%04llx)\n",
- ich_info->name, ich_info->iTCO_version, (u64)TCOBASE);
+ pdata->name, pdata->version, (u64)TCOBASE);

/* Clear out the (probably old) status */
if (iTCO_wdt_private.iTCO_version == 3) {
diff --git a/include/linux/mfd/lpc_ich.h b/include/linux/mfd/lpc_ich.h
index 8feac782fa83..2b300b44f994 100644
--- a/include/linux/mfd/lpc_ich.h
+++ b/include/linux/mfd/lpc_ich.h
@@ -20,12 +20,6 @@
#ifndef LPC_ICH_H
#define LPC_ICH_H

-/* Watchdog resources */
-#define ICH_RES_IO_TCO 0
-#define ICH_RES_IO_SMI 1
-#define ICH_RES_MEM_OFF 2
-#define ICH_RES_MEM_GCS_PMC 0
-
/* GPIO resources */
#define ICH_RES_GPIO 0
#define ICH_RES_GPE0 1
diff --git a/include/linux/platform_data/itco_wdt.h b/include/linux/platform_data/itco_wdt.h
new file mode 100644
index 000000000000..f16542c77ff7
--- /dev/null
+++ b/include/linux/platform_data/itco_wdt.h
@@ -0,0 +1,19 @@
+/*
+ * Platform data for the Intel TCO Watchdog
+ */
+
+#ifndef _ITCO_WDT_H_
+#define _ITCO_WDT_H_
+
+/* Watchdog resources */
+#define ICH_RES_IO_TCO 0
+#define ICH_RES_IO_SMI 1
+#define ICH_RES_MEM_OFF 2
+#define ICH_RES_MEM_GCS_PMC 0
+
+struct itco_wdt_platform_data {
+ char name[32];
+ unsigned int version;
+};
+
+#endif /* _ITCO_WDT_H_ */


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