--- /dev/null
+/*
+ * early_printk_mrst.c - spi-uart early printk for Intel Moorestown platform
+ *
+ * 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.
+ */
+
+#include <linux/kmsg_dump.h>
+#include <linux/console.h>
+#include <linux/kernel.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,
+};
git.openpandora.org / pandora-kernel.git / commitdiff