[Patch v2 1/3] misc: pch_phub: Read prefetch value from device tree if passed

From: Zubair Lutfullah Kakakhel
Date: Fri Aug 12 2016 - 07:49:21 EST


The default prefetch value for the eg20t device is hard coded to
0x000affaa.

Add support for an alternative to be read from DT if available

Signed-off-by: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@xxxxxxxxxx>

---
V1 -> V2
added #include <linux/of.h>
---
drivers/misc/pch_phub.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/pch_phub.c b/drivers/misc/pch_phub.c
index 4810e03..1dd18f5 100644
--- a/drivers/misc/pch_phub.c
+++ b/drivers/misc/pch_phub.c
@@ -28,6 +28,7 @@
#include <linux/if_ether.h>
#include <linux/ctype.h>
#include <linux/dmi.h>
+#include <linux/of.h>

#define PHUB_STATUS 0x00 /* Status Register offset */
#define PHUB_CONTROL 0x04 /* Control Register offset */
@@ -711,6 +712,12 @@ static int pch_phub_probe(struct pci_dev *pdev,

if (id->driver_data == 1) { /* EG20T PCH */
const char *board_name;
+ unsigned int prefetch = 0x000affaa;
+
+ if (pdev->dev.of_node)
+ of_property_read_u32(pdev->dev.of_node,
+ "intel,eg20t-prefetch",
+ &prefetch);

ret = sysfs_create_file(&pdev->dev.kobj,
&dev_attr_pch_mac.attr);
@@ -736,7 +743,7 @@ static int pch_phub_probe(struct pci_dev *pdev,
CLKCFG_UART_MASK);

/* set the prefech value */
- iowrite32(0x000affaa, chip->pch_phub_base_address + 0x14);
+ iowrite32(prefetch, chip->pch_phub_base_address + 0x14);
/* set the interrupt delay value */
iowrite32(0x25, chip->pch_phub_base_address + 0x44);
chip->pch_opt_rom_start_address = PCH_PHUB_ROM_START_ADDR_EG20T;
--
1.9.1