From: Feng Tang <feng.tang@xxxxxxxxx>
To enable early printk of HSU console, simply set "earlyprint=hsu" in
kernel command line.
Currently we put the code in the mrst_earlyprintk.c and it need enable
CONFIG_X86_MRST_EARLY_PRINTK config option
Signed-off-by: Feng Tang <feng.tang@xxxxxxxxx>
Signed-off-by: Alan Cox <alan@xxxxxxxxxxxxxxx>
---
arch/x86/include/asm/mrst.h | 1
arch/x86/kernel/early_printk.c | 3 +
arch/x86/kernel/mrst_earlyprintk.c | 128 ++++++++++++++++++++++++++++++++++++
3 files changed, 132 insertions(+), 0 deletions(-)
diff --git a/arch/x86/include/asm/mrst.h b/arch/x86/include/asm/mrst.h
index 704d2fd..b6531da 100644
--- a/arch/x86/include/asm/mrst.h
+++ b/arch/x86/include/asm/mrst.h
@@ -46,5 +46,6 @@ extern enum mrst_timer_options mrst_timer_options;
#define SFI_MRTC_MAX 8
extern struct console early_mrst_console;
+extern struct console early_hsu_console;
extern void mrst_early_printk(const char *fmt, ...);
#endif /* _ASM_X86_MRST_H */
diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c
index 435a070..fd095e7 100644
--- a/arch/x86/kernel/early_printk.c
+++ b/arch/x86/kernel/early_printk.c
@@ -243,6 +243,9 @@ static int __init setup_early_printk(char *buf)
#ifdef CONFIG_X86_MRST_EARLY_PRINTK
if (!strncmp(buf, "mrst", 4))
early_console_register(&early_mrst_console, keep);
+
+ if (!strncmp(buf, "hsu", 3))
+ early_console_register(&early_hsu_console, keep);
#endif
buf++;
}
diff --git a/arch/x86/kernel/mrst_earlyprintk.c b/arch/x86/kernel/mrst_earlyprintk.c
index 4aff765..1fb1305 100644
--- a/arch/x86/kernel/mrst_earlyprintk.c
+++ b/arch/x86/kernel/mrst_earlyprintk.c
@@ -9,9 +9,12 @@
* of the License.
*/
+#include <linux/serial_reg.h>
+#include <linux/serial_mfd.h>
#include <linux/kmsg_dump.h>
#include <linux/console.h>
#include <linux/kernel.h>
+#include <linux/delay.h>
#include <linux/init.h>
#include <linux/io.h>
@@ -281,3 +284,128 @@ void mrst_early_printk(const char *fmt, ...)
early_mrst_console.write(&early_mrst_console, buf, n);
}
+
+
+/* Will use HSU port2 for early console */
+
+/*
+ * Note:
+ * 1. still need GPIO workaround for UART2
+ *
+ */
+static spinlock_t hsu_lock;
+static int hsu_inited;
+static void __iomem *phsu;
+#define HSU_PORT2_PADDR 0xffa28180
+#define MFD_GPIO_HSU_REG 0xff12c064
+
+static void early_hsu_init(void)
+{
+ u8 lcr;
+
+ if (phsu && hsu_inited)
+ return;
+
+ spin_lock_init(&hsu_lock);
+
+ /* GPIO workaround */
+ set_fixmap_nocache(FIX_EARLYCON_MEM_BASE, MFD_GPIO_HSU_REG);
+ phsu = (void *)(__fix_to_virt(FIX_EARLYCON_MEM_BASE) +
+ (MFD_GPIO_HSU_REG & (PAGE_SIZE - 1)));
+
+ *((u32 *)phsu) = 0x55465;
+
+ set_fixmap_nocache(FIX_EARLYCON_MEM_BASE, HSU_PORT2_PADDR);
+ phsu = (void *)(__fix_to_virt(FIX_EARLYCON_MEM_BASE) +
+ (HSU_PORT2_PADDR & (PAGE_SIZE - 1)));
+
+ writeb(0x0, phsu + UART_FCR);
+
+ /* set to default 115200 */
+ lcr = readb(phsu + UART_LCR);
+ writeb((0x80 | lcr), phsu + UART_LCR);
+ writeb(0x18, phsu + UART_DLL);
+ writeb(lcr, phsu + UART_LCR);
+ writel(0x3600, phsu + UART_MUL*4);
+
+ writeb(0x8, phsu + UART_MCR);
+ writeb(0x7, phsu + UART_FCR);
+ writeb(0x3, phsu + UART_LCR);
+
+ /* clear IRQ status */
+ readb(phsu + UART_LSR);
+ readb(phsu + UART_RX);
+ readb(phsu + UART_IIR);
+ readb(phsu + UART_MSR);
+
+
+
+ writeb(0x7, phsu + UART_FCR);
+
+ hsu_inited = 1;
+}
+
+#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
+static void early_hsu_putc(char ch)
+{
+ unsigned int timeout = 10000; /* 10ms*/
+ u8 status;
+
+ while (timeout--) {
+ status = readb(phsu + UART_LSR);
+ if (status & BOTH_EMPTY)
+ break;
+
+ udelay(1);
+ }
+
+ if (timeout == 0xffffffff)
+ return;
+
+ writeb(ch, phsu + UART_TX);
+}
+
+static void early_hsu_write(struct console *con,
+ const char *str, unsigned n)
+{
+ int i;
+ unsigned long flags;
+
+ /*
+ printk("%s(): enter\n\n", __func__);
+ */
+
+ if (unlikely(!hsu_inited))
+ early_hsu_init();
+
+ spin_lock_irqsave(&hsu_lock, flags);
+ for (i = 0; i < n && *str; i++) {
+ if (*str == '\n')
+ early_hsu_putc('\r');
+ early_hsu_putc(*str);
+
+ str++;
+ }
+ spin_unlock_irqrestore(&hsu_lock, flags);
+}
+
+
+struct console early_hsu_console = {
+ .name = "earlyhsu",
+ .write = early_hsu_write,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+};
+
+void hsu_early_printk(const char *fmt, ...)
+{
+ char buf[512];
+ int n;
+ va_list ap;
+
+ va_start(ap, fmt);
+ n = vscnprintf(buf, 512, fmt, ap);
+ va_end(ap);
+
+ early_hsu_console.write(&early_mrst_console, buf, n);
+}
--
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