[Patch v2 2/3] misc: pch_phub: Add UART_CLK quirk for Boston platform

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



The EG20T has 4 UART blocks. The clock source for the UART block is
configured to receive a clock from an external pin by default.

An internal 25MHz clock in the EG20T can also be used as a clock source
for the clock.

The MIPS based Boston platform ties the external clock pin down and relies
on the internal clock source for the UART to function.

Boston is based on device tree.

Add a quirk to allow Boston to be detected via device tree and set the
correct clock source for UART.

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

---
V1 -> V2

no change
---
 drivers/misc/pch_phub.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/misc/pch_phub.c b/drivers/misc/pch_phub.c
index 1dd18f5..e42bdc9 100644
--- a/drivers/misc/pch_phub.c
+++ b/drivers/misc/pch_phub.c
@@ -58,6 +58,7 @@
 
 /* CM-iTC */
 #define CLKCFG_UART_48MHZ			(1 << 16)
+#define CLKCFG_UART_25MHZ			(2 << 16)
 #define CLKCFG_BAUDDIV				(2 << 20)
 #define CLKCFG_PLL2VCO				(8 << 9)
 #define CLKCFG_UARTCLKSEL			(1 << 18)
@@ -748,6 +749,16 @@ static int pch_phub_probe(struct pci_dev *pdev,
 		iowrite32(0x25, chip->pch_phub_base_address + 0x44);
 		chip->pch_opt_rom_start_address = PCH_PHUB_ROM_START_ADDR_EG20T;
 		chip->pch_mac_start_address = PCH_PHUB_MAC_START_ADDR_EG20T;
+
+		/* quirk for MIPS Boston platform */
+		if (pdev->dev.of_node) {
+			if (of_machine_is_compatible("img,boston")) {
+				pch_phub_read_modify_write_reg(chip,
+					(unsigned int)CLKCFG_REG_OFFSET,
+					CLKCFG_UART_25MHZ,
+					CLKCFG_UART_MASK);
+			}
+		}
 	} else if (id->driver_data == 2) { /* ML7213 IOH */
 		ret = sysfs_create_bin_file(&pdev->dev.kobj, &pch_bin_attr);
 		if (ret)
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-serial" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Kernel Newbies]     [Security]     [Netfilter]     [Bugtraq]     [Linux PPP]     [Linux FS]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Video 4 Linux]     [Linmodem]     [Device Mapper]     [Linux Kernel for ARM]

  Powered by Linux