From 59e21a2ab9b7554acf2c15dc9ee191e76bebade7 Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
Date: Fri, 4 Nov 2011 16:00:34 +0100
Subject: [PATCH 36/70] I2C: MIPS: lantiq: add FALC-ON i2c bus master

This patch adds the driver needed to make the I2C bus work on FALC-ON SoCs.

Signed-off-by: Thomas Langer <thomas.langer@lantiq.com>
Signed-off-by: John Crispin <blogic@openwrt.org>
Cc: linux-i2c@vger.kernel.org
---
 .../include/asm/mach-lantiq/falcon/lantiq_soc.h    |    5 +
 arch/mips/lantiq/falcon/clk.c                      |   44 -
 arch/mips/lantiq/falcon/devices.c                  |   16 +
 arch/mips/lantiq/falcon/devices.h                  |    1 +
 arch/mips/lantiq/falcon/mach-easy98000.c           |    1 +
 drivers/i2c/busses/Kconfig                         |   10 +
 drivers/i2c/busses/Makefile                        |    1 +
 drivers/i2c/busses/i2c-falcon.c                    | 1040 ++++++++++++++++++++
 8 files changed, 1074 insertions(+), 44 deletions(-)
 delete mode 100644 arch/mips/lantiq/falcon/clk.c
 create mode 100644 drivers/i2c/busses/i2c-falcon.c

--- a/arch/mips/include/asm/mach-lantiq/falcon/lantiq_soc.h
+++ b/arch/mips/include/asm/mach-lantiq/falcon/lantiq_soc.h
@@ -72,6 +72,10 @@
 #define LTQ_PADCTRL4_BASE_ADDR  0x1E800600
 #define LTQ_PADCTRL4_SIZE       0x0100
 
+/* I2C */
+#define GPON_I2C_BASE		0x1E200000
+#define GPON_I2C_SIZE		0x00010000
+
 /* CHIP ID */
 #define LTQ_STATUS_BASE_ADDR	0x1E802000
 
@@ -106,6 +110,7 @@
 #define ACTS_PADCTRL2	0x00200000
 #define ACTS_PADCTRL3	0x00200000
 #define ACTS_PADCTRL4	0x00400000
+#define ACTS_I2C_ACT	0x00004000
 
 /* global register ranges */
 extern __iomem void *ltq_ebu_membase;
--- a/arch/mips/lantiq/falcon/clk.c
+++ /dev/null
@@ -1,44 +0,0 @@
-/*
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published
- * by the Free Software Foundation.
- *
- * Copyright (C) 2011 Thomas Langer <thomas.langer@lantiq.com>
- * Copyright (C) 2011 John Crispin <blogic@openwrt.org>
- */
-
-#include <linux/ioport.h>
-#include <linux/export.h>
-
-#include <lantiq_soc.h>
-
-#include "devices.h"
-
-/* CPU0 Clock Control Register */
-#define LTQ_SYS1_CPU0CC		0x0040
-/* clock divider bit */
-#define LTQ_CPU0CC_CPUDIV	0x0001
-
-unsigned int
-ltq_get_io_region_clock(void)
-{
-	return CLOCK_200M;
-}
-EXPORT_SYMBOL(ltq_get_io_region_clock);
-
-unsigned int
-ltq_get_cpu_hz(void)
-{
-	if (ltq_sys1_r32(LTQ_SYS1_CPU0CC) & LTQ_CPU0CC_CPUDIV)
-		return CLOCK_200M;
-	else
-		return CLOCK_400M;
-}
-EXPORT_SYMBOL(ltq_get_cpu_hz);
-
-unsigned int
-ltq_get_fpi_hz(void)
-{
-	return CLOCK_100M;
-}
-EXPORT_SYMBOL(ltq_get_fpi_hz);
--- a/arch/mips/lantiq/falcon/devices.c
+++ b/arch/mips/lantiq/falcon/devices.c
@@ -134,3 +134,19 @@ falcon_register_spi_flash(struct spi_boa
 	spi_register_board_info(data, 1);
 	platform_device_register(&ltq_spi);
 }
+
+/* i2c */
+static struct resource falcon_i2c_resources[] = {
+	MEM_RES("i2c", GPON_I2C_BASE, GPON_I2C_SIZE),
+	IRQ_RES(i2c_lb, FALCON_IRQ_I2C_LBREQ),
+	IRQ_RES(i2c_b, FALCON_IRQ_I2C_BREQ),
+	IRQ_RES(i2c_err, FALCON_IRQ_I2C_I2C_ERR),
+	IRQ_RES(i2c_p, FALCON_IRQ_I2C_I2C_P),
+};
+
+void __init
+falcon_register_i2c(void)
+{
+	platform_device_register_simple("i2c-falcon", 0,
+		falcon_i2c_resources, ARRAY_SIZE(falcon_i2c_resources));
+}
--- a/arch/mips/lantiq/falcon/devices.h
+++ b/arch/mips/lantiq/falcon/devices.h
@@ -20,5 +20,6 @@ extern void falcon_register_nand(void);
 extern void falcon_register_gpio(void);
 extern void falcon_register_gpio_extra(void);
 extern void falcon_register_spi_flash(struct spi_board_info *data);
+extern void falcon_register_i2c(void);
 
 #endif
--- a/arch/mips/lantiq/falcon/mach-easy98000.c
+++ b/arch/mips/lantiq/falcon/mach-easy98000.c
@@ -98,6 +98,7 @@ easy98000_init_common(void)
 {
 	spi_register_board_info(&easy98000_spi_gpio_devices, 1);
 	platform_device_register(&easy98000_spi_gpio_device);
+	falcon_register_i2c();
 }
 
 static void __init
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -369,6 +369,16 @@ config I2C_DESIGNWARE_PCI
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-designware-pci.
 
+config I2C_FALCON
+	tristate "Falcon I2C interface"
+	depends on SOC_FALCON
+	help
+	  If you say yes to this option, support will be included for the
+	  Lantiq FALC-ON I2C core.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called i2c-falcon.
+
 config I2C_GPIO
 	tristate "GPIO-based bitbanging I2C"
 	depends on GENERIC_GPIO
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -37,6 +37,7 @@ obj-$(CONFIG_I2C_DESIGNWARE_PLATFORM)	+=
 i2c-designware-platform-objs := i2c-designware-platdrv.o i2c-designware-core.o
 obj-$(CONFIG_I2C_DESIGNWARE_PCI)	+= i2c-designware-pci.o
 i2c-designware-pci-objs := i2c-designware-pcidrv.o i2c-designware-core.o
+obj-$(CONFIG_I2C_FALCON)	+= i2c-falcon.o
 obj-$(CONFIG_I2C_GPIO)		+= i2c-gpio.o
 obj-$(CONFIG_I2C_HIGHLANDER)	+= i2c-highlander.o
 obj-$(CONFIG_I2C_IBM_IIC)	+= i2c-ibm_iic.o
--- /dev/null
+++ b/drivers/i2c/busses/i2c-falcon.c
@@ -0,0 +1,1040 @@
+/*
+ * Lantiq FALC(tm) ON - I2C bus adapter
+ *
+ * Parts based on i2c-designware.c and other i2c drivers from Linux 2.6.33
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Copyright (C) 2010 Thomas Langer <thomas.langer@lantiq.com>
+ */
+
+/*
+ * CURRENT ISSUES:
+ * - no high speed support
+ * - supports only master mode
+ * - ten bit mode is not tested (no slave devices)
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/clk.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/gpio.h>
+
+#include <lantiq_soc.h>
+
+/* I2C Identification Register */
+/* Module ID */
+#define I2C_ID_ID_MASK 0x0000FF00
+/* field offset */
+#define I2C_ID_ID_OFFSET 8
+/* Revision */
+#define I2C_ID_REV_MASK 0x000000FF
+/* field offset */
+#define I2C_ID_REV_OFFSET 0
+
+/* I2C Error Interrupt Request Source Status Register */
+/* TXF_OFL */
+#define I2C_ERR_IRQSS_TXF_OFL 0x00000008
+/* TXF_UFL */
+#define I2C_ERR_IRQSS_TXF_UFL 0x00000004
+/* RXF_OFL */
+#define I2C_ERR_IRQSS_RXF_OFL 0x00000002
+/* RXF_UFL */
+#define I2C_ERR_IRQSS_RXF_UFL 0x00000001
+
+/* I2C Bus Status Register */
+/* Bus Status */
+#define I2C_BUS_STAT_BS_MASK 0x00000003
+/* I2C Bus is free. */
+#define I2C_BUS_STAT_BS_FREE 0x00000000
+/*
+ * The device is working as master and has claimed the control
+ * on the I2C-bus (busy master).
+ */
+#define I2C_BUS_STAT_BS_BM 0x00000002
+
+/* I2C Interrupt Clear Register */
+/* Clear */
+#define I2C_ICR_BREQ_INT_CLR 0x00000008
+/* Clear */
+#define I2C_ICR_LBREQ_INT_CLR 0x00000004
+
+/* I2C RUN Control Register */
+/* Enable */
+#define I2C_RUN_CTRL_RUN_EN 0x00000001
+
+/* I2C Kernel Clock Control Register */
+/* field offset */
+#define I2C_CLC_RMC_OFFSET 8
+/* Enable */
+#define I2C_IMSC_I2C_P_INT_EN 0x00000020
+/* Enable */
+#define I2C_IMSC_I2C_ERR_INT_EN 0x00000010
+/* Enable */
+#define I2C_IMSC_BREQ_INT_EN 0x00000008
+/* Enable */
+#define I2C_IMSC_LBREQ_INT_EN 0x00000004
+
+/* I2C Fractional Divider Configuration Register */
+/* field offset */
+#define I2C_FDIV_CFG_INC_OFFSET 16
+/* field offset */
+#define I2C_FDIV_CFG_DEC_OFFSET 0
+
+/* I2C Fractional Divider (highspeed mode) Configuration Register */
+/* field offset */
+#define I2C_FDIV_HIGH_CFG_INC_OFFSET 16
+/* field offset */
+#define I2C_FDIV_HIGH_CFG_DEC_OFFSET 0
+
+/* I2C Address Register */
+/* Enable */
+#define I2C_ADDR_CFG_SOPE_EN 0x00200000
+/* Enable */
+#define I2C_ADDR_CFG_SONA_EN 0x00100000
+/* Enable */
+#define I2C_ADDR_CFG_MnS_EN 0x00080000
+
+/* I2C Protocol Interrupt Request Source Status Register */
+/* RX */
+#define I2C_P_IRQSS_RX 0x00000040
+/* TX_END */
+#define I2C_P_IRQSS_TX_END 0x00000020
+/* NACK */
+#define I2C_P_IRQSS_NACK 0x00000010
+/* AL */
+#define I2C_P_IRQSS_AL 0x00000008
+
+/* I2C Raw Interrupt Status Register */
+/* Read: Interrupt occurred. */
+#define I2C_RIS_I2C_P_INT_INTOCC 0x00000020
+/* Read: Interrupt occurred. */
+#define I2C_RIS_I2C_ERR_INT_INTOCC 0x00000010
+
+/* I2C End Data Control Register */
+/*
+ * Set End of Transmission - Note: Do not write '1' to this bit when bus is
+ * free. This will cause an abort after the first byte when a new transfer
+ * is started.
+ */
+#define I2C_ENDD_CTRL_SETEND 0x00000002
+/* TX FIFO Flow Control */
+#define I2C_FIFO_CFG_TXFC 0x00020000
+/* RX FIFO Flow Control */
+#define I2C_FIFO_CFG_RXFC 0x00010000
+/* Word aligned (character alignment of four characters) */
+#define I2C_FIFO_CFG_TXFA_TXFA2 0x00002000
+/* Word aligned (character alignment of four characters) */
+#define I2C_FIFO_CFG_RXFA_RXFA2 0x00000200
+/* 1 word */
+#define I2C_FIFO_CFG_TXBS_TXBS0 0x00000000
+/* 1 word */
+#define I2C_FIFO_CFG_RXBS_RXBS0 0x00000000
+
+
+/* I2C register structure */
+struct gpon_reg_i2c {
+	/* I2C Kernel Clock Control Register */
+	unsigned int clc; /* 0x00000000 */
+	/* Reserved */
+	unsigned int res_0; /* 0x00000004 */
+	/* I2C Identification Register */
+	unsigned int id; /* 0x00000008 */
+	/* Reserved */
+	unsigned int res_1; /* 0x0000000C */
+	/*
+	 * I2C RUN Control Register - This register enables and disables the I2C
+	 * peripheral. Before enabling, the I2C has to be configured properly.
+	 * After enabling no configuration is possible
+	 */
+	unsigned int run_ctrl; /* 0x00000010 */
+	/*
+	 * I2C End Data Control Register - This register is used to either turn
+	 * around the data transmission direction or to address another slave
+	 * without sending a stop condition. Also the software can stop the
+	 * slave-transmitter by sending a not-accolade when working as
+	 * master-receiver or even stop data transmission immediately when
+	 * operating as master-transmitter. The writing to the bits of this
+	 * control register is only effective when in MASTER RECEIVES BYTES,
+	 * MASTER TRANSMITS BYTES, MASTER RESTART or SLAVE RECEIVE BYTES state
+	 */
+	unsigned int endd_ctrl; /* 0x00000014 */
+	/*
+	 * I2C Fractional Divider Configuration Register - These register is
+	 * used to program the fractional divider of the I2C bus. Before the
+	 * peripheral is switched on by setting the RUN-bit the two (fixed)
+	 * values for the two operating frequencies are programmed into these
+	 * (configuration) registers. The Register FDIV_HIGH_CFG has the same
+	 * layout as I2C_FDIV_CFG.
+	 */
+	unsigned int fdiv_cfg; /* 0x00000018 */
+	/*
+	 * I2C Fractional Divider (highspeed mode) Configuration Register
+	 * These register is used to program the fractional divider of the I2C
+	 * bus. Before the peripheral is switched on by setting the RUN-bit the
+	 * two (fixed) values for the two operating frequencies are programmed
+	 * into these (configuration) registers. The Register FDIV_CFG has the
+	 * same layout as I2C_FDIV_CFG.
+	 */
+	unsigned int fdiv_high_cfg; /* 0x0000001C */
+	/* I2C Address Configuration Register */
+	unsigned int addr_cfg; /* 0x00000020 */
+	/*
+	 * I2C Bus Status Register - This register gives a status information
+	 * of the I2C. This additional information can be used by the software
+	 * to start proper actions.
+	 */
+	unsigned int bus_stat; /* 0x00000024 */
+	/* I2C FIFO Configuration Register */
+	unsigned int fifo_cfg; /* 0x00000028 */
+	/* I2C Maximum Received Packet Size Register */
+	unsigned int mrps_ctrl; /* 0x0000002C */
+	/* I2C Received Packet Size Status Register */
+	unsigned int rps_stat; /* 0x00000030 */
+	/* I2C Transmit Packet Size Register */
+	unsigned int tps_ctrl; /* 0x00000034 */
+	/* I2C Filled FIFO Stages Status Register */
+	unsigned int ffs_stat; /* 0x00000038 */
+	/* Reserved */
+	unsigned int res_2; /* 0x0000003C */
+	/* I2C Timing Configuration Register */
+	unsigned int tim_cfg; /* 0x00000040 */
+	/* Reserved */
+		unsigned int res_3[7]; /* 0x00000044 */
+	/* I2C Error Interrupt Request Source Mask Register */
+	unsigned int err_irqsm; /* 0x00000060 */
+	/* I2C Error Interrupt Request Source Status Register */
+	unsigned int err_irqss; /* 0x00000064 */
+	/* I2C Error Interrupt Request Source Clear Register */
+	unsigned int err_irqsc; /* 0x00000068 */
+	/* Reserved */
+	unsigned int res_4; /* 0x0000006C */
+	/* I2C Protocol Interrupt Request Source Mask Register */
+	unsigned int p_irqsm; /* 0x00000070 */
+	/* I2C Protocol Interrupt Request Source Status Register */
+	unsigned int p_irqss; /* 0x00000074 */
+	/* I2C Protocol Interrupt Request Source Clear Register */
+	unsigned int p_irqsc; /* 0x00000078 */
+	/* Reserved */
+	unsigned int res_5; /* 0x0000007C */
+	/* I2C Raw Interrupt Status Register */
+	unsigned int ris; /* 0x00000080 */
+	/* I2C Interrupt Mask Control Register */
+	unsigned int imsc; /* 0x00000084 */
+	/* I2C Masked Interrupt Status Register */
+	unsigned int mis; /* 0x00000088 */
+	/* I2C Interrupt Clear Register */
+	unsigned int icr; /* 0x0000008C */
+	/* I2C Interrupt Set Register */
+	unsigned int isr; /* 0x00000090 */
+	/* I2C DMA Enable Register */
+	unsigned int dmae; /* 0x00000094 */
+	/* Reserved */
+	unsigned int res_6[8154]; /* 0x00000098 */
+	/* I2C Transmit Data Register */
+	unsigned int txd; /* 0x00008000 */
+	/* Reserved */
+	unsigned int res_7[4095]; /* 0x00008004 */
+	/* I2C Receive Data Register */
+	unsigned int rxd; /* 0x0000C000 */
+	/* Reserved */
+	unsigned int res_8[4095]; /* 0x0000C004 */
+};
+
+/* mapping for access macros */
+#define i2c	((struct gpon_reg_i2c *)priv->membase)
+#define reg_r32(reg)		__raw_readl(reg)
+#define reg_w32(val, reg)	__raw_writel(val, reg)
+#define reg_w32_mask(clear, set, reg)	\
+				reg_w32((reg_r32(reg) & ~(clear)) | (set), reg)
+#define reg_r32_table(reg, idx) reg_r32(&((uint32_t *)&reg)[idx])
+#define reg_w32_table(val, reg, idx) reg_w32(val, &((uint32_t *)&reg)[idx])
+
+#define i2c_r32(reg) reg_r32(&i2c->reg)
+#define i2c_w32(val, reg) reg_w32(val, &i2c->reg)
+#define i2c_w32_mask(clear, set, reg) reg_w32_mask(clear, set, &i2c->reg)
+
+#define DRV_NAME "i2c-falcon"
+#define DRV_VERSION "1.01"
+
+#define FALCON_I2C_BUSY_TIMEOUT		20 /* ms */
+
+#ifdef DEBUG
+#define FALCON_I2C_XFER_TIMEOUT		(25 * HZ)
+#else
+#define FALCON_I2C_XFER_TIMEOUT		HZ
+#endif
+#if defined(DEBUG) && 0
+#define PRINTK(arg...) pr_info(arg)
+#else
+#define PRINTK(arg...) do {} while (0)
+#endif
+
+#define FALCON_I2C_IMSC_DEFAULT_MASK	(I2C_IMSC_I2C_P_INT_EN | \
+					 I2C_IMSC_I2C_ERR_INT_EN)
+
+#define FALCON_I2C_ARB_LOST	(1 << 0)
+#define FALCON_I2C_NACK		(1 << 1)
+#define FALCON_I2C_RX_UFL	(1 << 2)
+#define FALCON_I2C_RX_OFL	(1 << 3)
+#define FALCON_I2C_TX_UFL	(1 << 4)
+#define FALCON_I2C_TX_OFL	(1 << 5)
+
+struct falcon_i2c {
+	struct mutex mutex;
+
+	enum {
+		FALCON_I2C_MODE_100	= 1,
+		FALCON_I2C_MODE_400	= 2,
+		FALCON_I2C_MODE_3400	= 3
+	} mode;				/* current speed mode */
+
+	struct clk *clk;		/* clock input for i2c hardware block */
+	struct gpon_reg_i2c __iomem *membase;	/* base of mapped registers */
+	int irq_lb, irq_b, irq_err, irq_p;	/* last burst, burst, error,
+						   protocol IRQs */
+
+	struct i2c_adapter adap;
+	struct device *dev;
+
+	struct completion	cmd_complete;
+
+	/* message transfer data */
+	/* current message */
+	struct i2c_msg		*current_msg;
+	/* number of messages to handle */
+	int			msgs_num;
+	/* current buffer */
+	u8			*msg_buf;
+	/* remaining length of current buffer */
+	u32			msg_buf_len;
+	/* error status of the current transfer */
+	int			msg_err;
+
+	/* master status codes */
+	enum {
+		STATUS_IDLE,
+		STATUS_ADDR,	/* address phase */
+		STATUS_WRITE,
+		STATUS_READ,
+		STATUS_READ_END,
+		STATUS_STOP
+	} status;
+};
+
+static irqreturn_t falcon_i2c_isr(int irq, void *dev_id);
+
+static inline void enable_burst_irq(struct falcon_i2c *priv)
+{
+	i2c_w32_mask(0, I2C_IMSC_LBREQ_INT_EN | I2C_IMSC_BREQ_INT_EN, imsc);
+}
+static inline void disable_burst_irq(struct falcon_i2c *priv)
+{
+	i2c_w32_mask(I2C_IMSC_LBREQ_INT_EN | I2C_IMSC_BREQ_INT_EN, 0, imsc);
+}
+
+static void prepare_msg_send_addr(struct falcon_i2c *priv)
+{
+	struct i2c_msg *msg = priv->current_msg;
+	int rd = !!(msg->flags & I2C_M_RD);
+	u16 addr = msg->addr;
+
+	/* new i2c_msg */
+	priv->msg_buf = msg->buf;
+	priv->msg_buf_len = msg->len;
+	if (rd)
+		priv->status = STATUS_READ;
+	else
+		priv->status = STATUS_WRITE;
+
+	/* send slave address */
+	if (msg->flags & I2C_M_TEN) {
+		i2c_w32(0xf0 | ((addr & 0x300) >> 7) | rd, txd);
+		i2c_w32(addr & 0xff, txd);
+	} else
+		i2c_w32((addr & 0x7f) << 1 | rd, txd);
+}
+
+static void set_tx_len(struct falcon_i2c *priv)
+{
+	struct i2c_msg *msg = priv->current_msg;
+	int len = (msg->flags & I2C_M_TEN) ? 2 : 1;
+
+	PRINTK("set_tx_len %cX\n", (msg->flags & I2C_M_RD) ? ('R') : ('T'));
+
+	priv->status = STATUS_ADDR;
+
+	if (!(msg->flags & I2C_M_RD)) {
+		len += msg->len;
+	} else {
+		/* set maximum received packet size (before rx int!) */
+		i2c_w32(msg->len, mrps_ctrl);
+	}
+	i2c_w32(len, tps_ctrl);
+	enable_burst_irq(priv);
+}
+
+static int falcon_i2c_hw_init(struct i2c_adapter *adap)
+{
+	struct falcon_i2c *priv = i2c_get_adapdata(adap);
+
+	/* disable bus */
+	i2c_w32_mask(I2C_RUN_CTRL_RUN_EN, 0, run_ctrl);
+
+#ifndef DEBUG
+	/* set normal operation clock divider */
+	i2c_w32(1 << I2C_CLC_RMC_OFFSET, clc);
+#else
+	/* for debugging a higher divider value! */
+	i2c_w32(0xF0 << I2C_CLC_RMC_OFFSET, clc);
+#endif
+
+	/* set frequency */
+	if (priv->mode == FALCON_I2C_MODE_100) {
+		dev_dbg(priv->dev, "set standard mode (100 kHz)\n");
+		i2c_w32(0, fdiv_high_cfg);
+		i2c_w32((1 << I2C_FDIV_CFG_INC_OFFSET) |
+			(499 << I2C_FDIV_CFG_DEC_OFFSET),
+			fdiv_cfg);
+	} else if (priv->mode == FALCON_I2C_MODE_400) {
+		dev_dbg(priv->dev, "set fast mode (400 kHz)\n");
+		i2c_w32(0, fdiv_high_cfg);
+		i2c_w32((1 << I2C_FDIV_CFG_INC_OFFSET) |
+			(124 << I2C_FDIV_CFG_DEC_OFFSET),
+			fdiv_cfg);
+	} else if (priv->mode == FALCON_I2C_MODE_3400) {
+		dev_dbg(priv->dev, "set high mode (3.4 MHz)\n");
+		i2c_w32(0, fdiv_cfg);
+		/* TODO recalculate value for 100MHz input */
+		i2c_w32((41 << I2C_FDIV_HIGH_CFG_INC_OFFSET) |
+			(152 << I2C_FDIV_HIGH_CFG_DEC_OFFSET),
+			fdiv_high_cfg);
+	} else {
+		dev_warn(priv->dev, "unknown mode\n");
+		return -ENODEV;
+	}
+
+	/* configure fifo */
+	i2c_w32(I2C_FIFO_CFG_TXFC | /* tx fifo as flow controller */
+		I2C_FIFO_CFG_RXFC | /* rx fifo as flow controller */
+		I2C_FIFO_CFG_TXFA_TXFA2 | /* tx fifo 4-byte aligned */
+		I2C_FIFO_CFG_RXFA_RXFA2 | /* rx fifo 4-byte aligned */
+		I2C_FIFO_CFG_TXBS_TXBS0 | /* tx fifo burst size is 1 word */
+		I2C_FIFO_CFG_RXBS_RXBS0,  /* rx fifo burst size is 1 word */
+		fifo_cfg);
+
+	/* configure address */
+	i2c_w32(I2C_ADDR_CFG_SOPE_EN |	/* generate stop when no more data
+					   in the fifo */
+		I2C_ADDR_CFG_SONA_EN |	/* generate stop when NA received */
+		I2C_ADDR_CFG_MnS_EN |	/* we are master device */
+		0,			/* our slave address (not used!) */
+		addr_cfg);
+
+	/* enable bus */
+	i2c_w32_mask(0, I2C_RUN_CTRL_RUN_EN, run_ctrl);
+
+	return 0;
+}
+
+static int falcon_i2c_wait_bus_not_busy(struct falcon_i2c *priv)
+{
+	int timeout = FALCON_I2C_BUSY_TIMEOUT;
+
+	while ((i2c_r32(bus_stat) & I2C_BUS_STAT_BS_MASK)
+				 != I2C_BUS_STAT_BS_FREE) {
+		if (timeout <= 0) {
+			dev_warn(priv->dev, "timeout waiting for bus ready\n");
+			return -ETIMEDOUT;
+		}
+		timeout--;
+		mdelay(1);
+	}
+
+	return 0;
+}
+
+static void falcon_i2c_tx(struct falcon_i2c *priv, int last)
+{
+	if (priv->msg_buf_len && priv->msg_buf) {
+		i2c_w32(*priv->msg_buf, txd);
+
+		if (--priv->msg_buf_len)
+			priv->msg_buf++;
+		else
+			priv->msg_buf = NULL;
+	} else
+		last = 1;
+
+	if (last)
+		disable_burst_irq(priv);
+}
+
+static void falcon_i2c_rx(struct falcon_i2c *priv, int last)
+{
+	u32 fifo_stat, timeout;
+	if (priv->msg_buf_len && priv->msg_buf) {
+		timeout = 5000000;
+		do {
+			fifo_stat = i2c_r32(ffs_stat);
+		} while (!fifo_stat && --timeout);
+		if (!timeout) {
+			last = 1;
+			PRINTK("\nrx timeout\n");
+			goto err;
+		}
+		while (fifo_stat) {
+			*priv->msg_buf = i2c_r32(rxd);
+			if (--priv->msg_buf_len)
+				priv->msg_buf++;
+			else {
+				priv->msg_buf = NULL;
+				last = 1;
+				break;
+			}
+			#if 0
+			fifo_stat = i2c_r32(ffs_stat);
+			#else
+			/* do not read more than burst size, otherwise no "last
+			burst" is generated and the transaction is blocked! */
+			fifo_stat = 0;
+			#endif
+		}
+	} else {
+		last = 1;
+	}
+err:
+	if (last) {
+		disable_burst_irq(priv);
+
+		if (priv->status == STATUS_READ_END) {
+			/* do the STATUS_STOP and complete() here, as sometimes
+			   the tx_end is already seen before this is finished */
+			priv->status = STATUS_STOP;
+			complete(&priv->cmd_complete);
+		} else {
+			i2c_w32(I2C_ENDD_CTRL_SETEND, endd_ctrl);
+			priv->status = STATUS_READ_END;
+		}
+	}
+}
+
+static void falcon_i2c_xfer_init(struct falcon_i2c *priv)
+{
+	/* enable interrupts */
+	i2c_w32(FALCON_I2C_IMSC_DEFAULT_MASK, imsc);
+
+	/* trigger transfer of first msg */
+	set_tx_len(priv);
+}
+
+static void dump_msgs(struct i2c_msg msgs[], int num, int rx)
+{
+#if defined(DEBUG)
+	int i, j;
+	pr_info("Messages %d %s\n", num, rx ? "out" : "in");
+	for (i = 0; i < num; i++) {
+		pr_info("%2d %cX Msg(%d) addr=0x%X: ", i,
+			(msgs[i].flags & I2C_M_RD) ? ('R') : ('T'),
+			msgs[i].len, msgs[i].addr);
+		if (!(msgs[i].flags & I2C_M_RD) || rx) {
+			for (j = 0; j < msgs[i].len; j++)
+				printk("%02X ", msgs[i].buf[j]);
+		}
+		printk("\n");
+	}
+#endif
+}
+
+static void falcon_i2c_release_bus(struct falcon_i2c *priv)
+{
+	if ((i2c_r32(bus_stat) & I2C_BUS_STAT_BS_MASK) == I2C_BUS_STAT_BS_BM)
+		i2c_w32(I2C_ENDD_CTRL_SETEND, endd_ctrl);
+}
+
+static int falcon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
+			   int num)
+{
+	struct falcon_i2c *priv = i2c_get_adapdata(adap);
+	int ret;
+
+	dev_dbg(priv->dev, "xfer %u messages\n", num);
+	dump_msgs(msgs, num, 0);
+
+	mutex_lock(&priv->mutex);
+
+	INIT_COMPLETION(priv->cmd_complete);
+	priv->current_msg = msgs;
+	priv->msgs_num = num;
+	priv->msg_err = 0;
+	priv->status = STATUS_IDLE;
+
+	/* wait for the bus to become ready */
+	ret = falcon_i2c_wait_bus_not_busy(priv);
+	if (ret)
+		goto done;
+
+	while (priv->msgs_num) {
+		/* start the transfers */
+		falcon_i2c_xfer_init(priv);
+
+		/* wait for transfers to complete */
+		ret = wait_for_completion_interruptible_timeout(
+			&priv->cmd_complete, FALCON_I2C_XFER_TIMEOUT);
+		if (ret == 0) {
+			dev_err(priv->dev, "controller timed out\n");
+			falcon_i2c_hw_init(adap);
+			ret = -ETIMEDOUT;
+			goto done;
+		} else if (ret < 0)
+			goto done;
+
+		if (priv->msg_err) {
+			if (priv->msg_err & FALCON_I2C_NACK)
+				ret = -ENXIO;
+			else
+				ret = -EREMOTEIO;
+			goto done;
+		}
+		if (--priv->msgs_num)
+			priv->current_msg++;
+	}
+	/* no error? */
+	ret = num;
+
+done:
+	falcon_i2c_release_bus(priv);
+
+	mutex_unlock(&priv->mutex);
+
+	if (ret >= 0)
+		dump_msgs(msgs, num, 1);
+
+	PRINTK("XFER ret %d\n", ret);
+	return ret;
+}
+
+static irqreturn_t falcon_i2c_isr_burst(int irq, void *dev_id)
+{
+	struct falcon_i2c *priv = dev_id;
+	struct i2c_msg *msg = priv->current_msg;
+	int last = (irq == priv->irq_lb);
+
+	if (last)
+		PRINTK("LB ");
+	else
+		PRINTK("B ");
+
+	if (msg->flags & I2C_M_RD) {
+		switch (priv->status) {
+		case STATUS_ADDR:
+			PRINTK("X");
+			prepare_msg_send_addr(priv);
+			disable_burst_irq(priv);
+			break;
+		case STATUS_READ:
+		case STATUS_READ_END:
+			PRINTK("R");
+			falcon_i2c_rx(priv, last);
+			break;
+		default:
+			disable_burst_irq(priv);
+			PRINTK("Status R %d\n", priv->status);
+			break;
+		}
+	} else {
+		switch (priv->status) {
+		case STATUS_ADDR:
+			PRINTK("x");
+			prepare_msg_send_addr(priv);
+			break;
+		case STATUS_WRITE:
+			PRINTK("w");
+			falcon_i2c_tx(priv, last);
+			break;
+		default:
+			disable_burst_irq(priv);
+			PRINTK("Status W %d\n", priv->status);
+			break;
+		}
+	}
+
+	i2c_w32(I2C_ICR_BREQ_INT_CLR | I2C_ICR_LBREQ_INT_CLR, icr);
+	return IRQ_HANDLED;
+}
+
+static void falcon_i2c_isr_prot(struct falcon_i2c *priv)
+{
+	u32 i_pro = i2c_r32(p_irqss);
+
+	PRINTK("i2c-p");
+
+	/* not acknowledge */
+	if (i_pro & I2C_P_IRQSS_NACK) {
+		priv->msg_err |= FALCON_I2C_NACK;
+		PRINTK(" nack");
+	}
+
+	/* arbitration lost */
+	if (i_pro & I2C_P_IRQSS_AL) {
+		priv->msg_err |= FALCON_I2C_ARB_LOST;
+		PRINTK(" arb-lost");
+	}
+	/* tx -> rx switch */
+	if (i_pro & I2C_P_IRQSS_RX)
+		PRINTK(" rx");
+
+	/* tx end */
+	if (i_pro & I2C_P_IRQSS_TX_END)
+		PRINTK(" txend");
+	PRINTK("\n");
+
+	if (!priv->msg_err) {
+		/* tx -> rx switch */
+		if (i_pro & I2C_P_IRQSS_RX) {
+			priv->status = STATUS_READ;
+			enable_burst_irq(priv);
+		}
+		if (i_pro & I2C_P_IRQSS_TX_END) {
+			if (priv->status == STATUS_READ)
+				priv->status = STATUS_READ_END;
+			else {
+				disable_burst_irq(priv);
+				priv->status = STATUS_STOP;
+			}
+		}
+	}
+
+	i2c_w32(i_pro, p_irqsc);
+}
+
+static irqreturn_t falcon_i2c_isr(int irq, void *dev_id)
+{
+	u32 i_raw, i_err = 0;
+	struct falcon_i2c *priv = dev_id;
+
+	i_raw = i2c_r32(mis);
+	PRINTK("i_raw 0x%08X\n", i_raw);
+
+	/* error interrupt */
+	if (i_raw & I2C_RIS_I2C_ERR_INT_INTOCC) {
+		i_err = i2c_r32(err_irqss);
+		PRINTK("i_err 0x%08X bus_stat 0x%04X\n",
+			i_err, i2c_r32(bus_stat));
+
+		/* tx fifo overflow (8) */
+		if (i_err & I2C_ERR_IRQSS_TXF_OFL)
+			priv->msg_err |= FALCON_I2C_TX_OFL;
+
+		/* tx fifo underflow (4) */
+		if (i_err & I2C_ERR_IRQSS_TXF_UFL)
+			priv->msg_err |= FALCON_I2C_TX_UFL;
+
+		/* rx fifo overflow (2) */
+		if (i_err & I2C_ERR_IRQSS_RXF_OFL)
+			priv->msg_err |= FALCON_I2C_RX_OFL;
+
+		/* rx fifo underflow (1) */
+		if (i_err & I2C_ERR_IRQSS_RXF_UFL)
+			priv->msg_err |= FALCON_I2C_RX_UFL;
+
+		i2c_w32(i_err, err_irqsc);
+	}
+
+	/* protocol interrupt */
+	if (i_raw & I2C_RIS_I2C_P_INT_INTOCC)
+		falcon_i2c_isr_prot(priv);
+
+	if ((priv->msg_err) || (priv->status == STATUS_STOP))
+		complete(&priv->cmd_complete);
+
+	return IRQ_HANDLED;
+}
+
+static u32 falcon_i2c_functionality(struct i2c_adapter *adap)
+{
+	return	I2C_FUNC_I2C |
+		I2C_FUNC_10BIT_ADDR |
+		I2C_FUNC_SMBUS_EMUL;
+}
+
+static struct i2c_algorithm falcon_i2c_algorithm = {
+	.master_xfer	= falcon_i2c_xfer,
+	.functionality	= falcon_i2c_functionality,
+};
+
+static int __devinit falcon_i2c_probe(struct platform_device *pdev)
+{
+	int ret = 0;
+	struct falcon_i2c *priv;
+	struct i2c_adapter *adap;
+	struct resource *mmres, *ioarea,
+			*irqres_lb, *irqres_b, *irqres_err, *irqres_p;
+	struct clk *clk;
+
+	dev_dbg(&pdev->dev, "probing\n");
+
+	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	irqres_lb = platform_get_resource_byname(pdev, IORESOURCE_IRQ,
+						 "i2c_lb");
+	irqres_b = platform_get_resource_byname(pdev, IORESOURCE_IRQ, "i2c_b");
+	irqres_err = platform_get_resource_byname(pdev, IORESOURCE_IRQ,
+						  "i2c_err");
+	irqres_p = platform_get_resource_byname(pdev, IORESOURCE_IRQ, "i2c_p");
+
+	if (!mmres || !irqres_lb || !irqres_b || !irqres_err || !irqres_p) {
+		dev_err(&pdev->dev, "no resources\n");
+		return -ENODEV;
+	}
+
+	clk = clk_get_fpi();
+	if (IS_ERR(clk)) {
+		dev_err(&pdev->dev, "failed to get fpi clk\n");
+		return -ENOENT;
+	}
+
+	if (clk_get_rate(clk) != 100000000) {
+		dev_err(&pdev->dev, "input clock is not 100MHz\n");
+		return -ENOENT;
+	}
+	clk = clk_get(&pdev->dev, NULL);
+	if (IS_ERR(clk)) {
+		dev_err(&pdev->dev, "failed to get i2c clk\n");
+		return -ENOENT;
+	}
+
+	/* allocate private data */
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv) {
+		dev_err(&pdev->dev, "can't allocate private data\n");
+		return -ENOMEM;
+	}
+
+	adap = &priv->adap;
+	i2c_set_adapdata(adap, priv);
+	adap->owner = THIS_MODULE;
+	adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
+	strlcpy(adap->name, DRV_NAME "-adapter", sizeof(adap->name));
+	adap->algo = &falcon_i2c_algorithm;
+
+	priv->mode = FALCON_I2C_MODE_100;
+	priv->clk = clk;
+	priv->dev = &pdev->dev;
+
+	init_completion(&priv->cmd_complete);
+	mutex_init(&priv->mutex);
+
+	if (ltq_gpio_request(&pdev->dev, 107, 0, 0, DRV_NAME":sda") ||
+		ltq_gpio_request(&pdev->dev, 108, 0, 0, DRV_NAME":scl"))
+	{
+		dev_err(&pdev->dev, "I2C gpios not available\n");
+		ret = -ENXIO;
+		goto err_free_priv;
+	}
+
+	ioarea = request_mem_region(mmres->start, resource_size(mmres),
+					 pdev->name);
+
+	if (ioarea == NULL) {
+		dev_err(&pdev->dev, "I2C region already claimed\n");
+		ret = -ENXIO;
+		goto err_free_gpio;
+	}
+
+	/* map memory */
+	priv->membase = ioremap_nocache(mmres->start & ~KSEG1,
+		resource_size(mmres));
+	if (priv->membase == NULL) {
+		ret = -ENOMEM;
+		goto err_release_region;
+	}
+
+	priv->irq_lb = irqres_lb->start;
+	ret = request_irq(priv->irq_lb, falcon_i2c_isr_burst, IRQF_DISABLED,
+			  irqres_lb->name, priv);
+	if (ret) {
+		dev_err(&pdev->dev, "can't get last burst IRQ %d\n",
+					irqres_lb->start);
+		ret = -ENODEV;
+		goto err_unmap_mem;
+	}
+
+	priv->irq_b = irqres_b->start;
+	ret = request_irq(priv->irq_b, falcon_i2c_isr_burst, IRQF_DISABLED,
+			  irqres_b->name, priv);
+	if (ret) {
+		dev_err(&pdev->dev, "can't get burst IRQ %d\n",
+					irqres_b->start);
+		ret = -ENODEV;
+		goto err_free_lb_irq;
+	}
+
+	priv->irq_err = irqres_err->start;
+	ret = request_irq(priv->irq_err, falcon_i2c_isr, IRQF_DISABLED,
+			  irqres_err->name, priv);
+	if (ret) {
+		dev_err(&pdev->dev, "can't get error IRQ %d\n",
+					irqres_err->start);
+		ret = -ENODEV;
+		goto err_free_b_irq;
+	}
+
+	priv->irq_p = irqres_p->start;
+	ret = request_irq(priv->irq_p, falcon_i2c_isr, IRQF_DISABLED,
+			  irqres_p->name, priv);
+	if (ret) {
+		dev_err(&pdev->dev, "can't get protocol IRQ %d\n",
+					irqres_p->start);
+		ret = -ENODEV;
+		goto err_free_err_irq;
+	}
+
+	dev_dbg(&pdev->dev, "mapped io-space to %p\n", priv->membase);
+	dev_dbg(&pdev->dev, "use IRQs %d, %d, %d, %d\n", irqres_lb->start,
+	    irqres_b->start, irqres_err->start, irqres_p->start);
+
+	/* add our adapter to the i2c stack */
+	ret = i2c_add_numbered_adapter(adap);
+	if (ret) {
+		dev_err(&pdev->dev, "can't register I2C adapter\n");
+		goto err_free_p_irq;
+	}
+
+	platform_set_drvdata(pdev, priv);
+	i2c_set_adapdata(adap, priv);
+
+	/* print module version information */
+	dev_dbg(&pdev->dev, "module id=%u revision=%u\n",
+		(i2c_r32(id) & I2C_ID_ID_MASK) >> I2C_ID_ID_OFFSET,
+		(i2c_r32(id) & I2C_ID_REV_MASK) >> I2C_ID_REV_OFFSET);
+
+	/* initialize HW */
+	ret = falcon_i2c_hw_init(adap);
+	if (ret) {
+		dev_err(&pdev->dev, "can't configure adapter\n");
+		goto err_remove_adapter;
+	}
+
+	dev_info(&pdev->dev, "version %s\n", DRV_VERSION);
+
+	return 0;
+
+err_remove_adapter:
+	i2c_del_adapter(adap);
+	platform_set_drvdata(pdev, NULL);
+
+err_free_p_irq:
+	free_irq(priv->irq_p, priv);
+
+err_free_err_irq:
+	free_irq(priv->irq_err, priv);
+
+err_free_b_irq:
+	free_irq(priv->irq_b, priv);
+
+err_free_lb_irq:
+	free_irq(priv->irq_lb, priv);
+
+err_unmap_mem:
+	iounmap(priv->membase);
+
+err_release_region:
+	release_mem_region(mmres->start, resource_size(mmres));
+
+err_free_gpio:
+	gpio_free(108);
+	gpio_free(107);
+
+err_free_priv:
+	kfree(priv);
+
+	return ret;
+}
+
+static int __devexit falcon_i2c_remove(struct platform_device *pdev)
+{
+	struct falcon_i2c *priv = platform_get_drvdata(pdev);
+	struct resource *mmres;
+
+	/* disable bus */
+	i2c_w32_mask(I2C_RUN_CTRL_RUN_EN, 0, run_ctrl);
+
+	/* remove driver */
+	platform_set_drvdata(pdev, NULL);
+	i2c_del_adapter(&priv->adap);
+
+	free_irq(priv->irq_lb, priv);
+	free_irq(priv->irq_b, priv);
+	free_irq(priv->irq_err, priv);
+	free_irq(priv->irq_p, priv);
+
+	iounmap(priv->membase);
+
+	gpio_free(108);
+	gpio_free(107);
+
+	kfree(priv);
+
+	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	release_mem_region(mmres->start, resource_size(mmres));
+
+	dev_dbg(&pdev->dev, "removed\n");
+
+	return 0;
+}
+
+static struct platform_driver falcon_i2c_driver = {
+	.probe	= falcon_i2c_probe,
+	.remove	= __devexit_p(falcon_i2c_remove),
+	.driver	= {
+		.name	= DRV_NAME,
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init falcon_i2c_init(void)
+{
+	int ret;
+
+	ret = platform_driver_register(&falcon_i2c_driver);
+
+	if (ret)
+		pr_debug(DRV_NAME ": can't register platform driver\n");
+
+	return ret;
+}
+
+static void __exit falcon_i2c_exit(void)
+{
+	platform_driver_unregister(&falcon_i2c_driver);
+}
+
+module_init(falcon_i2c_init);
+module_exit(falcon_i2c_exit);
+
+MODULE_DESCRIPTION("Lantiq FALC(tm) ON - I2C bus adapter");
+MODULE_ALIAS("platform:" DRV_NAME);
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRV_VERSION);
