pch_uart: reference clock on CM-iTC

[Denis Turischev <denis@compulab.co.il>]

Default clock source for UARTs on Topcliff is external UART_CLK.
On CM-iTC USB_48MHz is used unstead. After VCO2PLL and DIV
manipulations UARTs will receive 192 MHz.
Clock manipulations on Topcliff are controlled in pch_phub.c

Signed-off-by: Denis Turischev <denis@compulab.co.il>
---
 drivers/misc/pch_phub.c       |   16 ++++++++++++++++
 drivers/tty/serial/pch_uart.c |    9 +++++++--
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/pch_phub.c b/drivers/misc/pch_phub.c
index 744b804..50cb839 100644
--- a/drivers/misc/pch_phub.c
+++ b/drivers/misc/pch_phub.c
@@ -27,6 +27,7 @@
 #include <linux/mutex.h>
 #include <linux/if_ether.h>
 #include <linux/ctype.h>
+#include <linux/dmi.h>

 #define PHUB_STATUS 0x00		/* Status Register offset */
 #define PHUB_CONTROL 0x04		/* Control Register offset */
@@ -41,6 +42,13 @@
 #define PCH_MINOR_NOS 1
 #define CLKCFG_CAN_50MHZ 0x12000000
 #define CLKCFG_CANCLK_MASK 0xFF000000
+#define CLKCFG_UART_MASK			0xFFFFFF
+
+/* CM-iTC */
+#define CLKCFG_UART_48MHZ			(1 << 16)
+#define CLKCFG_BAUDDIV				(2 << 20)
+#define CLKCFG_PLL2VCO				(8 << 9)
+#define CLKCFG_UARTCLKSEL			(1 << 18)

 /* SROM ACCESS Macro */
 #define PCH_WORD_ADDR_MASK (~((1 << 2) - 1))
@@ -607,6 +615,14 @@ static int __devinit pch_phub_probe(struct pci_dev *pdev,
 	pch_phub_read_modify_write_reg(chip, (unsigned int)CLKCFG_REG_OFFSET,
 					CLKCFG_CAN_50MHZ, CLKCFG_CANCLK_MASK);

+	/* quirk for CM-iTC board */
+	if (strstr(dmi_get_system_info(DMI_BOARD_NAME), "CM-iTC"))
+		pch_phub_read_modify_write_reg(chip,
+					(unsigned int)CLKCFG_REG_OFFSET,
+					CLKCFG_UART_48MHZ | CLKCFG_BAUDDIV |
+					CLKCFG_PLL2VCO | CLKCFG_UARTCLKSEL,
+					CLKCFG_UART_MASK);
+
 	/* set the prefech value */
 	iowrite32(0x000affaa, chip->pch_phub_base_address + 0x14);
 	/* set the interrupt delay value */
diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
index 70a6145..9689ac6 100644
--- a/drivers/tty/serial/pch_uart.c
+++ b/drivers/tty/serial/pch_uart.c
@@ -21,6 +21,7 @@
 #include <linux/serial_core.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
+#include <linux/dmi.h>

 #include <linux/dmaengine.h>
 #include <linux/pch_dma.h>
@@ -1267,14 +1268,18 @@ static struct eg20t_port *pch_uart_init_port(struct pci_dev *pdev,
 	if (!rxbuf)
 		goto init_port_free_txbuf;

+	base_baud = 1843200; /* 1.8432MHz */
+
+	/* quirk for CM-iTC board */
+	if (strstr(dmi_get_system_info(DMI_BOARD_NAME), "CM-iTC"))
+		base_baud = 192000000; /* 192.0MHz */
+
 	switch (port_type) {
 	case PORT_UNKNOWN:
 		fifosize = 256; /* UART0 */
-		base_baud = 1843200; /* 1.8432MHz */
 		break;
 	case PORT_8250:
 		fifosize = 64; /* UART1~3 */
-		base_baud = 1843200; /* 1.8432MHz */
 		break;
 	default:
 		dev_err(&pdev->dev, "Invalid Port Type(=%d)\n", port_type);
-- 
1.7.0.4

-- 
Denis