/*
* early_printk_mrst.c - early consoles for Intel MID platforms
*
* Copyright (c) 2008-2010, Intel Corporation
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; version 2
* of the License.
*/
/*
* This file implements two early consoles named mrst and hsu.
* mrst is based on Maxim3110 spi-uart device, it exists in both
* Moorestown and Medfield platforms, while hsu is based on a High
* Speed UART device which only exists in the Medfield platform
*/
#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>
#include <asm/fixmap.h>
#include <asm/pgtable.h>
#include <asm/mrst.h>
#define MRST_SPI_TIMEOUT 0x200000
#define MRST_REGBASE_SPI0 0xff128000
#define MRST_REGBASE_SPI1 0xff128400
#define MRST_CLK_SPI0_REG 0xff11d86c
/* Bit fields in CTRLR0 */
#define SPI_DFS_OFFSET 0
#define SPI_FRF_OFFSET 4
#define SPI_FRF_SPI 0x0
#define SPI_FRF_SSP 0x1
#define SPI_FRF_MICROWIRE 0x2
#define SPI_FRF_RESV 0x3
#define SPI_MODE_OFFSET 6
#define SPI_SCPH_OFFSET 6
#define SPI_SCOL_OFFSET 7
#define SPI_TMOD_OFFSET 8
#define SPI_TMOD_TR 0x0 /* xmit & recv */
#define SPI_TMOD_TO 0x1 /* xmit only */
#define SPI_TMOD_RO 0x2 /* recv only */
#define SPI_TMOD_EPROMREAD 0x3 /* eeprom read mode */
#define SPI_SLVOE_OFFSET 10
#define SPI_SRL_OFFSET 11
#define SPI_CFS_OFFSET 12
/* Bit fields in SR, 7 bits */
#define SR_MASK 0x7f /* cover 7 bits */
#define SR_BUSY (1 << 0)
#define SR_TF_NOT_FULL (1 << 1)
#define SR_TF_EMPT (1 << 2)
#define SR_RF_NOT_EMPT (1 << 3)
#define SR_RF_FULL (1 << 4)
#define SR_TX_ERR (1 << 5)
#define SR_DCOL (1 << 6)
struct dw_spi_reg {
u32 ctrl0;
u32 ctrl1;
u32 ssienr;
u32 mwcr;
u32 ser;
u32 baudr;
u32 txfltr;
u32 rxfltr;
u32 txflr;
u32 rxflr;
u32 sr;
u32 imr;
u32 isr;
u32 risr;
u32 txoicr;
u32 rxoicr;
u32 rxuicr;
u32 msticr;
u32 icr;
u32 dmacr;
u32 dmatdlr;
u32 dmardlr;
u32 idr;
u32 version;
/* Currently operates as 32 bits, though only the low 16 bits matter */
u32 dr;
} __packed;
#define dw_readl(dw, name) __raw_readl(&(dw)->name)
#define dw_writel(dw, name, val) __raw_writel((val), &(dw)->name)
/* Default use SPI0 register for mrst, we will detect Penwell and use SPI1 */
static unsigned long mrst_spi_paddr = MRST_REGBASE_SPI0;
static u32 *pclk_spi0;
/* Always contains an accessable address, start with 0 */
static struct dw_spi_reg *pspi;
static struct kmsg_dumper dw_dumper;
static int dumper_registered;
static void dw_kmsg_dump(struct kmsg_dumper *dumper,
enum kmsg_dump_reason reason,
const char *s1, unsigned long l1,
const char *s2, unsigned long l2)
{
int i;
/* When run to this, we'd better re-init the HW */
mrst_early_console_init();
for (i = 0; i < l1; i++)
early_mrst_console.write(&early_mrst_console, s1 + i, 1);
for (i = 0; i < l2; i++)
early_mrst_console.write(&early_mrst_console, s2 + i, 1);
}
/* Set the ratio rate to 115200, 8n1, IRQ disabled */
static void max3110_write_config(void)
{
u16 config;
config = 0xc001;
dw_writel(pspi, dr, config);
}
/* Translate char to a eligible word and send to max3110 */
static void max3110_write_data(char c)
{
u16 data;
data = 0x8000 | c;
dw_writel(pspi, dr, data);
}
void mrst_early_console_init(void)
{
u32 ctrlr0 = 0;
u32 spi0_cdiv;
u32 freq; /* Freqency info only need be searched once */
/* Base clk is 100 MHz, the actual clk = 100M / (clk_divider + 1) */
pclk_spi0 = (void *)set_fixmap_offset_nocache(FIX_EARLYCON_MEM_BASE,
MRST_CLK_SPI0_REG);
spi0_cdiv = ((*pclk_spi0) & 0xe00) >> 9;
freq = 100000000 / (spi0_cdiv + 1);
if (mrst_identify_cpu() == MRST_CPU_CHIP_PENWELL)
mrst_spi_paddr = MRST_REGBASE_SPI1;
pspi = (void *)set_fixmap_offset_nocache(FIX_EARLYCON_MEM_BASE,
mrst_spi_paddr);
/* Disable SPI controller */
dw_writel(pspi, ssienr, 0);
/* Set control param, 8 bits, transmit only mode */
ctrlr0 = dw_readl(pspi, ctrl0);
ctrlr0 &= 0xfcc0;
ctrlr0 |= 0xf | (SPI_FRF_SPI << SPI_FRF_OFFSET)
| (SPI_TMOD_TO << SPI_TMOD_OFFSET);
dw_writel(pspi, ctrl0, ctrlr0);
/*
* Change the spi0 clk to comply with 115200 bps, use 100000 to
* calculate the clk dividor to make the clock a little slower
* than real baud rate.
*/
dw_writel(pspi, baudr, freq/100000);
/* Disable all INT for early phase */
dw_writel(pspi, imr, 0x0);
/* Set the cs to spi-uart */
dw_writel(pspi, ser, 0x2);
/* Enable the HW, the last step for HW init */
dw_writel(pspi, ssienr, 0x1);
/* Set the default configuration */
max3110_write_config();
/* Register the kmsg dumper */
if (!dumper_registered) {
dw_dumper.dump = dw_kmsg_dump;
kmsg_dump_register(&dw_dumper);
dumper_registered = 1;
}
}
/* Slave select should be called in the read/write function */
static void early_mrst_spi_putc(char c)
{
unsigned int timeout;
u32 sr;
timeout = MRST_SPI_TIMEOUT;
/* Early putc needs to make sure the TX FIFO is not full */
while (--timeout) {
sr = dw_readl(pspi, sr);
if (!(sr & SR_TF_NOT_FULL))
cpu_relax();
else
break;
}
if (!timeout)
pr_warning("MRST earlycon: timed out\n");
else
max3110_write_data(c);
}
/* Early SPI only uses polling mode */
static void early_mrst_spi_write(struct console *con, const char *str, unsigned n)
{
int i;
for (i = 0; i < n && *str; i++) {
if (*str == '\n')
early_mrst_spi_putc('\r');
early_mrst_spi_putc(*str);
str++;
}
}
struct console early_mrst_console = {
.name = "earlymrst",
.write = early_mrst_spi_write,
.flags = CON_PRINTBUFFER,
.index = -1,
};
/*
* Following is the early console based on Medfield HSU (High
* Speed UART) device.
*/
#define HSU_PORT2_PADDR 0xffa28180
static void __iomem *phsu;
void hsu_early_console_init(void)
{
u8 lcr;
phsu = (void *)set_fixmap_offset_nocache(FIX_EARLYCON_MEM_BASE,
HSU_PORT2_PADDR);
/* Disable FIFO */
writeb(0x0, phsu + UART_FCR);
/* Set to default 115200 bps, 8n1 */
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);
/* Enable FIFO */
writeb(0x7, phsu + UART_FCR);
}
#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);
}
/* Only write the char when there was no timeout */
if (timeout)
writeb(ch, phsu + UART_TX);
}
static void early_hsu_write(struct console *con, const char *str, unsigned n)
{
int i;
for (i = 0; i < n && *str; i++) {
if (*str == '\n')
early_hsu_putc('\r');
early_hsu_putc(*str);
str++;
}
}
struct console early_hsu_console = {
.name = "earlyhsu",
.write = early_hsu_write,
.flags = CON_PRINTBUFFER,
.index = -1,
};
