[PATCH v3] pch_uart: reference clock on CM-iTC

From: Denis Turischev
Date: Thu Mar 10 2011 - 08:16:25 EST


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

v2: redone against the linux-next tree
v3: redone against linux/kernel/git/next/linux-next.git snapshot

Signed-off-by: Denis Turischev <denis@xxxxxxxxxxxxxx>
---
diff -Nru linux-next-20110310.orig/drivers/misc/pch_phub.c linux-next-20110310/drivers/misc/pch_phub.c
--- linux-next-20110310.orig/drivers/misc/pch_phub.c 2011-03-10 08:31:30.000000000 +0200
+++ linux-next-20110310/drivers/misc/pch_phub.c 2011-03-10 14:42:05.110978473 +0200
@@ -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 */
@@ -46,6 +47,13 @@
#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)

/* Macros for ML7213 */
#define PCI_VENDOR_ID_ROHM 0x10db
@@ -618,6 +626,14 @@
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 -Nru linux-next-20110310.orig/drivers/tty/serial/pch_uart.c linux-next-20110310/drivers/tty/serial/pch_uart.c
--- linux-next-20110310.orig/drivers/tty/serial/pch_uart.c 2011-03-10 08:31:30.000000000 +0200
+++ linux-next-20110310/drivers/tty/serial/pch_uart.c 2011-03-10 14:45:46.123478166 +0200
@@ -20,6 +20,7 @@
#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>
@@ -1403,14 +1404,18 @@
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; /* EG20T/ML7213: UART0 */
- base_baud = 1843200; /* 1.8432MHz */
break;
case PORT_8250:
fifosize = 64; /* EG20T:UART1~3 ML7213: UART1~2*/
- base_baud = 1843200; /* 1.8432MHz */
break;
default:
dev_err(&pdev->dev, "Invalid Port Type(=%d)\n", port_type);
--
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