diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-mv64xxx.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-mv64xxx.c | 1003 |
1 files changed, 1003 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c new file mode 100644 index 000000000..30059c1df --- /dev/null +++ b/drivers/i2c/busses/i2c-mv64xxx.c @@ -0,0 +1,1003 @@ +/* + * Driver for the i2c controller on the Marvell line of host bridges + * (e.g, gt642[46]0, mv643[46]0, mv644[46]0, and Orion SoC family). + * + * Author: Mark A. Greer <mgreer@mvista.com> + * + * 2005 (c) MontaVista, Software, Inc. This file is licensed under + * the terms of the GNU General Public License version 2. This program + * is licensed "as is" without any warranty of any kind, whether express + * or implied. + */ +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/spinlock.h> +#include <linux/i2c.h> +#include <linux/interrupt.h> +#include <linux/mv643xx_i2c.h> +#include <linux/platform_device.h> +#include <linux/reset.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/of_irq.h> +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/delay.h> + +#define MV64XXX_I2C_ADDR_ADDR(val) ((val & 0x7f) << 1) +#define MV64XXX_I2C_BAUD_DIV_N(val) (val & 0x7) +#define MV64XXX_I2C_BAUD_DIV_M(val) ((val & 0xf) << 3) + +#define MV64XXX_I2C_REG_CONTROL_ACK BIT(2) +#define MV64XXX_I2C_REG_CONTROL_IFLG BIT(3) +#define MV64XXX_I2C_REG_CONTROL_STOP BIT(4) +#define MV64XXX_I2C_REG_CONTROL_START BIT(5) +#define MV64XXX_I2C_REG_CONTROL_TWSIEN BIT(6) +#define MV64XXX_I2C_REG_CONTROL_INTEN BIT(7) + +/* Ctlr status values */ +#define MV64XXX_I2C_STATUS_BUS_ERR 0x00 +#define MV64XXX_I2C_STATUS_MAST_START 0x08 +#define MV64XXX_I2C_STATUS_MAST_REPEAT_START 0x10 +#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK 0x18 +#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK 0x20 +#define MV64XXX_I2C_STATUS_MAST_WR_ACK 0x28 +#define MV64XXX_I2C_STATUS_MAST_WR_NO_ACK 0x30 +#define MV64XXX_I2C_STATUS_MAST_LOST_ARB 0x38 +#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK 0x40 +#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK 0x48 +#define MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK 0x50 +#define MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK 0x58 +#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK 0xd0 +#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_NO_ACK 0xd8 +#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK 0xe0 +#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_NO_ACK 0xe8 +#define MV64XXX_I2C_STATUS_NO_STATUS 0xf8 + +/* Register defines (I2C bridge) */ +#define MV64XXX_I2C_REG_TX_DATA_LO 0xc0 +#define MV64XXX_I2C_REG_TX_DATA_HI 0xc4 +#define MV64XXX_I2C_REG_RX_DATA_LO 0xc8 +#define MV64XXX_I2C_REG_RX_DATA_HI 0xcc +#define MV64XXX_I2C_REG_BRIDGE_CONTROL 0xd0 +#define MV64XXX_I2C_REG_BRIDGE_STATUS 0xd4 +#define MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE 0xd8 +#define MV64XXX_I2C_REG_BRIDGE_INTR_MASK 0xdC +#define MV64XXX_I2C_REG_BRIDGE_TIMING 0xe0 + +/* Bridge Control values */ +#define MV64XXX_I2C_BRIDGE_CONTROL_WR BIT(0) +#define MV64XXX_I2C_BRIDGE_CONTROL_RD BIT(1) +#define MV64XXX_I2C_BRIDGE_CONTROL_ADDR_SHIFT 2 +#define MV64XXX_I2C_BRIDGE_CONTROL_ADDR_EXT BIT(12) +#define MV64XXX_I2C_BRIDGE_CONTROL_TX_SIZE_SHIFT 13 +#define MV64XXX_I2C_BRIDGE_CONTROL_RX_SIZE_SHIFT 16 +#define MV64XXX_I2C_BRIDGE_CONTROL_ENABLE BIT(19) +#define MV64XXX_I2C_BRIDGE_CONTROL_REPEATED_START BIT(20) + +/* Bridge Status values */ +#define MV64XXX_I2C_BRIDGE_STATUS_ERROR BIT(0) + +/* Driver states */ +enum { + MV64XXX_I2C_STATE_INVALID, + MV64XXX_I2C_STATE_IDLE, + MV64XXX_I2C_STATE_WAITING_FOR_START_COND, + MV64XXX_I2C_STATE_WAITING_FOR_RESTART, + MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK, + MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK, + MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK, + MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA, +}; + +/* Driver actions */ +enum { + MV64XXX_I2C_ACTION_INVALID, + MV64XXX_I2C_ACTION_CONTINUE, + MV64XXX_I2C_ACTION_SEND_RESTART, + MV64XXX_I2C_ACTION_SEND_ADDR_1, + MV64XXX_I2C_ACTION_SEND_ADDR_2, + MV64XXX_I2C_ACTION_SEND_DATA, + MV64XXX_I2C_ACTION_RCV_DATA, + MV64XXX_I2C_ACTION_RCV_DATA_STOP, + MV64XXX_I2C_ACTION_SEND_STOP, +}; + +struct mv64xxx_i2c_regs { + u8 addr; + u8 ext_addr; + u8 data; + u8 control; + u8 status; + u8 clock; + u8 soft_reset; +}; + +struct mv64xxx_i2c_data { + struct i2c_msg *msgs; + int num_msgs; + int irq; + u32 state; + u32 action; + u32 aborting; + u32 cntl_bits; + void __iomem *reg_base; + struct mv64xxx_i2c_regs reg_offsets; + u32 addr1; + u32 addr2; + u32 bytes_left; + u32 byte_posn; + u32 send_stop; + u32 block; + int rc; + u32 freq_m; + u32 freq_n; +#if defined(CONFIG_HAVE_CLK) + struct clk *clk; +#endif + wait_queue_head_t waitq; + spinlock_t lock; + struct i2c_msg *msg; + struct i2c_adapter adapter; + bool offload_enabled; +/* 5us delay in order to avoid repeated start timing violation */ + bool errata_delay; + struct reset_control *rstc; + bool irq_clear_inverted; +}; + +static struct mv64xxx_i2c_regs mv64xxx_i2c_regs_mv64xxx = { + .addr = 0x00, + .ext_addr = 0x10, + .data = 0x04, + .control = 0x08, + .status = 0x0c, + .clock = 0x0c, + .soft_reset = 0x1c, +}; + +static struct mv64xxx_i2c_regs mv64xxx_i2c_regs_sun4i = { + .addr = 0x00, + .ext_addr = 0x04, + .data = 0x08, + .control = 0x0c, + .status = 0x10, + .clock = 0x14, + .soft_reset = 0x18, +}; + +static void +mv64xxx_i2c_prepare_for_io(struct mv64xxx_i2c_data *drv_data, + struct i2c_msg *msg) +{ + u32 dir = 0; + + drv_data->cntl_bits = MV64XXX_I2C_REG_CONTROL_ACK | + MV64XXX_I2C_REG_CONTROL_INTEN | MV64XXX_I2C_REG_CONTROL_TWSIEN; + + if (msg->flags & I2C_M_RD) + dir = 1; + + if (msg->flags & I2C_M_TEN) { + drv_data->addr1 = 0xf0 | (((u32)msg->addr & 0x300) >> 7) | dir; + drv_data->addr2 = (u32)msg->addr & 0xff; + } else { + drv_data->addr1 = MV64XXX_I2C_ADDR_ADDR((u32)msg->addr) | dir; + drv_data->addr2 = 0; + } +} + +/* + ***************************************************************************** + * + * Finite State Machine & Interrupt Routines + * + ***************************************************************************** + */ + +/* Reset hardware and initialize FSM */ +static void +mv64xxx_i2c_hw_init(struct mv64xxx_i2c_data *drv_data) +{ + if (drv_data->offload_enabled) { + writel(0, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL); + writel(0, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_TIMING); + writel(0, drv_data->reg_base + + MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE); + writel(0, drv_data->reg_base + + MV64XXX_I2C_REG_BRIDGE_INTR_MASK); + } + + writel(0, drv_data->reg_base + drv_data->reg_offsets.soft_reset); + writel(MV64XXX_I2C_BAUD_DIV_M(drv_data->freq_m) | MV64XXX_I2C_BAUD_DIV_N(drv_data->freq_n), + drv_data->reg_base + drv_data->reg_offsets.clock); + writel(0, drv_data->reg_base + drv_data->reg_offsets.addr); + writel(0, drv_data->reg_base + drv_data->reg_offsets.ext_addr); + writel(MV64XXX_I2C_REG_CONTROL_TWSIEN | MV64XXX_I2C_REG_CONTROL_STOP, + drv_data->reg_base + drv_data->reg_offsets.control); + drv_data->state = MV64XXX_I2C_STATE_IDLE; +} + +static void +mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status) +{ + /* + * If state is idle, then this is likely the remnants of an old + * operation that driver has given up on or the user has killed. + * If so, issue the stop condition and go to idle. + */ + if (drv_data->state == MV64XXX_I2C_STATE_IDLE) { + drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; + return; + } + + /* The status from the ctlr [mostly] tells us what to do next */ + switch (status) { + /* Start condition interrupt */ + case MV64XXX_I2C_STATUS_MAST_START: /* 0x08 */ + case MV64XXX_I2C_STATUS_MAST_REPEAT_START: /* 0x10 */ + drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_1; + drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK; + break; + + /* Performing a write */ + case MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK: /* 0x18 */ + if (drv_data->msg->flags & I2C_M_TEN) { + drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2; + drv_data->state = + MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK; + break; + } + /* FALLTHRU */ + case MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK: /* 0xd0 */ + case MV64XXX_I2C_STATUS_MAST_WR_ACK: /* 0x28 */ + if ((drv_data->bytes_left == 0) + || (drv_data->aborting + && (drv_data->byte_posn != 0))) { + if (drv_data->send_stop || drv_data->aborting) { + drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; + drv_data->state = MV64XXX_I2C_STATE_IDLE; + } else { + drv_data->action = + MV64XXX_I2C_ACTION_SEND_RESTART; + drv_data->state = + MV64XXX_I2C_STATE_WAITING_FOR_RESTART; + } + } else { + drv_data->action = MV64XXX_I2C_ACTION_SEND_DATA; + drv_data->state = + MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK; + drv_data->bytes_left--; + } + break; + + /* Performing a read */ + case MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK: /* 40 */ + if (drv_data->msg->flags & I2C_M_TEN) { + drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2; + drv_data->state = + MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK; + break; + } + /* FALLTHRU */ + case MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK: /* 0xe0 */ + if (drv_data->bytes_left == 0) { + drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; + drv_data->state = MV64XXX_I2C_STATE_IDLE; + break; + } + /* FALLTHRU */ + case MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK: /* 0x50 */ + if (status != MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK) + drv_data->action = MV64XXX_I2C_ACTION_CONTINUE; + else { + drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA; + drv_data->bytes_left--; + } + drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA; + + if ((drv_data->bytes_left == 1) || drv_data->aborting) + drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_ACK; + break; + + case MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK: /* 0x58 */ + drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA_STOP; + drv_data->state = MV64XXX_I2C_STATE_IDLE; + break; + + case MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK: /* 0x20 */ + case MV64XXX_I2C_STATUS_MAST_WR_NO_ACK: /* 30 */ + case MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK: /* 48 */ + /* Doesn't seem to be a device at other end */ + drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; + drv_data->state = MV64XXX_I2C_STATE_IDLE; + drv_data->rc = -ENXIO; + break; + + default: + dev_err(&drv_data->adapter.dev, + "mv64xxx_i2c_fsm: Ctlr Error -- state: 0x%x, " + "status: 0x%x, addr: 0x%x, flags: 0x%x\n", + drv_data->state, status, drv_data->msg->addr, + drv_data->msg->flags); + drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; + mv64xxx_i2c_hw_init(drv_data); + drv_data->rc = -EIO; + } +} + +static void mv64xxx_i2c_send_start(struct mv64xxx_i2c_data *drv_data) +{ + drv_data->msg = drv_data->msgs; + drv_data->byte_posn = 0; + drv_data->bytes_left = drv_data->msg->len; + drv_data->aborting = 0; + drv_data->rc = 0; + + mv64xxx_i2c_prepare_for_io(drv_data, drv_data->msgs); + writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_START, + drv_data->reg_base + drv_data->reg_offsets.control); +} + +static void +mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data) +{ + switch(drv_data->action) { + case MV64XXX_I2C_ACTION_SEND_RESTART: + /* We should only get here if we have further messages */ + BUG_ON(drv_data->num_msgs == 0); + + drv_data->msgs++; + drv_data->num_msgs--; + mv64xxx_i2c_send_start(drv_data); + + if (drv_data->errata_delay) + udelay(5); + + /* + * We're never at the start of the message here, and by this + * time it's already too late to do any protocol mangling. + * Thankfully, do not advertise support for that feature. + */ + drv_data->send_stop = drv_data->num_msgs == 1; + break; + + case MV64XXX_I2C_ACTION_CONTINUE: + writel(drv_data->cntl_bits, + drv_data->reg_base + drv_data->reg_offsets.control); + break; + + case MV64XXX_I2C_ACTION_SEND_ADDR_1: + writel(drv_data->addr1, + drv_data->reg_base + drv_data->reg_offsets.data); + writel(drv_data->cntl_bits, + drv_data->reg_base + drv_data->reg_offsets.control); + break; + + case MV64XXX_I2C_ACTION_SEND_ADDR_2: + writel(drv_data->addr2, + drv_data->reg_base + drv_data->reg_offsets.data); + writel(drv_data->cntl_bits, + drv_data->reg_base + drv_data->reg_offsets.control); + break; + + case MV64XXX_I2C_ACTION_SEND_DATA: + writel(drv_data->msg->buf[drv_data->byte_posn++], + drv_data->reg_base + drv_data->reg_offsets.data); + writel(drv_data->cntl_bits, + drv_data->reg_base + drv_data->reg_offsets.control); + break; + + case MV64XXX_I2C_ACTION_RCV_DATA: + drv_data->msg->buf[drv_data->byte_posn++] = + readl(drv_data->reg_base + drv_data->reg_offsets.data); + writel(drv_data->cntl_bits, + drv_data->reg_base + drv_data->reg_offsets.control); + break; + + case MV64XXX_I2C_ACTION_RCV_DATA_STOP: + drv_data->msg->buf[drv_data->byte_posn++] = + readl(drv_data->reg_base + drv_data->reg_offsets.data); + drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN; + writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP, + drv_data->reg_base + drv_data->reg_offsets.control); + drv_data->block = 0; + if (drv_data->errata_delay) + udelay(5); + + wake_up(&drv_data->waitq); + break; + + case MV64XXX_I2C_ACTION_INVALID: + default: + dev_err(&drv_data->adapter.dev, + "mv64xxx_i2c_do_action: Invalid action: %d\n", + drv_data->action); + drv_data->rc = -EIO; + + /* FALLTHRU */ + case MV64XXX_I2C_ACTION_SEND_STOP: + drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN; + writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP, + drv_data->reg_base + drv_data->reg_offsets.control); + drv_data->block = 0; + wake_up(&drv_data->waitq); + break; + } +} + +static void +mv64xxx_i2c_read_offload_rx_data(struct mv64xxx_i2c_data *drv_data, + struct i2c_msg *msg) +{ + u32 buf[2]; + + buf[0] = readl(drv_data->reg_base + MV64XXX_I2C_REG_RX_DATA_LO); + buf[1] = readl(drv_data->reg_base + MV64XXX_I2C_REG_RX_DATA_HI); + + memcpy(msg->buf, buf, msg->len); +} + +static int +mv64xxx_i2c_intr_offload(struct mv64xxx_i2c_data *drv_data) +{ + u32 cause, status; + + cause = readl(drv_data->reg_base + + MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE); + if (!cause) + return IRQ_NONE; + + status = readl(drv_data->reg_base + + MV64XXX_I2C_REG_BRIDGE_STATUS); + + if (status & MV64XXX_I2C_BRIDGE_STATUS_ERROR) { + drv_data->rc = -EIO; + goto out; + } + + drv_data->rc = 0; + + /* + * Transaction is a one message read transaction, read data + * for this message. + */ + if (drv_data->num_msgs == 1 && drv_data->msgs[0].flags & I2C_M_RD) { + mv64xxx_i2c_read_offload_rx_data(drv_data, drv_data->msgs); + drv_data->msgs++; + drv_data->num_msgs--; + } + /* + * Transaction is a two messages write/read transaction, read + * data for the second (read) message. + */ + else if (drv_data->num_msgs == 2 && + !(drv_data->msgs[0].flags & I2C_M_RD) && + drv_data->msgs[1].flags & I2C_M_RD) { + mv64xxx_i2c_read_offload_rx_data(drv_data, drv_data->msgs + 1); + drv_data->msgs += 2; + drv_data->num_msgs -= 2; + } + +out: + writel(0, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL); + writel(0, drv_data->reg_base + + MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE); + drv_data->block = 0; + + wake_up(&drv_data->waitq); + + return IRQ_HANDLED; +} + +static irqreturn_t +mv64xxx_i2c_intr(int irq, void *dev_id) +{ + struct mv64xxx_i2c_data *drv_data = dev_id; + unsigned long flags; + u32 status; + irqreturn_t rc = IRQ_NONE; + + spin_lock_irqsave(&drv_data->lock, flags); + + if (drv_data->offload_enabled) + rc = mv64xxx_i2c_intr_offload(drv_data); + + while (readl(drv_data->reg_base + drv_data->reg_offsets.control) & + MV64XXX_I2C_REG_CONTROL_IFLG) { + status = readl(drv_data->reg_base + drv_data->reg_offsets.status); + mv64xxx_i2c_fsm(drv_data, status); + mv64xxx_i2c_do_action(drv_data); + + if (drv_data->irq_clear_inverted) + writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_IFLG, + drv_data->reg_base + drv_data->reg_offsets.control); + + rc = IRQ_HANDLED; + } + spin_unlock_irqrestore(&drv_data->lock, flags); + + return rc; +} + +/* + ***************************************************************************** + * + * I2C Msg Execution Routines + * + ***************************************************************************** + */ +static void +mv64xxx_i2c_wait_for_completion(struct mv64xxx_i2c_data *drv_data) +{ + long time_left; + unsigned long flags; + char abort = 0; + + time_left = wait_event_timeout(drv_data->waitq, + !drv_data->block, drv_data->adapter.timeout); + + spin_lock_irqsave(&drv_data->lock, flags); + if (!time_left) { /* Timed out */ + drv_data->rc = -ETIMEDOUT; + abort = 1; + } else if (time_left < 0) { /* Interrupted/Error */ + drv_data->rc = time_left; /* errno value */ + abort = 1; + } + + if (abort && drv_data->block) { + drv_data->aborting = 1; + spin_unlock_irqrestore(&drv_data->lock, flags); + + time_left = wait_event_timeout(drv_data->waitq, + !drv_data->block, drv_data->adapter.timeout); + + if ((time_left <= 0) && drv_data->block) { + drv_data->state = MV64XXX_I2C_STATE_IDLE; + dev_err(&drv_data->adapter.dev, + "mv64xxx: I2C bus locked, block: %d, " + "time_left: %d\n", drv_data->block, + (int)time_left); + mv64xxx_i2c_hw_init(drv_data); + } + } else + spin_unlock_irqrestore(&drv_data->lock, flags); +} + +static int +mv64xxx_i2c_execute_msg(struct mv64xxx_i2c_data *drv_data, struct i2c_msg *msg, + int is_last) +{ + unsigned long flags; + + spin_lock_irqsave(&drv_data->lock, flags); + + drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_START_COND; + + drv_data->send_stop = is_last; + drv_data->block = 1; + mv64xxx_i2c_send_start(drv_data); + spin_unlock_irqrestore(&drv_data->lock, flags); + + mv64xxx_i2c_wait_for_completion(drv_data); + return drv_data->rc; +} + +static void +mv64xxx_i2c_prepare_tx(struct mv64xxx_i2c_data *drv_data) +{ + struct i2c_msg *msg = drv_data->msgs; + u32 buf[2]; + + memcpy(buf, msg->buf, msg->len); + + writel(buf[0], drv_data->reg_base + MV64XXX_I2C_REG_TX_DATA_LO); + writel(buf[1], drv_data->reg_base + MV64XXX_I2C_REG_TX_DATA_HI); +} + +static int +mv64xxx_i2c_offload_xfer(struct mv64xxx_i2c_data *drv_data) +{ + struct i2c_msg *msgs = drv_data->msgs; + int num = drv_data->num_msgs; + unsigned long ctrl_reg; + unsigned long flags; + + spin_lock_irqsave(&drv_data->lock, flags); + + /* Build transaction */ + ctrl_reg = MV64XXX_I2C_BRIDGE_CONTROL_ENABLE | + (msgs[0].addr << MV64XXX_I2C_BRIDGE_CONTROL_ADDR_SHIFT); + + if (msgs[0].flags & I2C_M_TEN) + ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_ADDR_EXT; + + /* Single write message transaction */ + if (num == 1 && !(msgs[0].flags & I2C_M_RD)) { + size_t len = msgs[0].len - 1; + + ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_WR | + (len << MV64XXX_I2C_BRIDGE_CONTROL_TX_SIZE_SHIFT); + mv64xxx_i2c_prepare_tx(drv_data); + } + /* Single read message transaction */ + else if (num == 1 && msgs[0].flags & I2C_M_RD) { + size_t len = msgs[0].len - 1; + + ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_RD | + (len << MV64XXX_I2C_BRIDGE_CONTROL_RX_SIZE_SHIFT); + } + /* + * Transaction with one write and one read message. This is + * guaranteed by the mv64xx_i2c_can_offload() checks. + */ + else if (num == 2) { + size_t lentx = msgs[0].len - 1; + size_t lenrx = msgs[1].len - 1; + + ctrl_reg |= + MV64XXX_I2C_BRIDGE_CONTROL_RD | + MV64XXX_I2C_BRIDGE_CONTROL_WR | + (lentx << MV64XXX_I2C_BRIDGE_CONTROL_TX_SIZE_SHIFT) | + (lenrx << MV64XXX_I2C_BRIDGE_CONTROL_RX_SIZE_SHIFT) | + MV64XXX_I2C_BRIDGE_CONTROL_REPEATED_START; + mv64xxx_i2c_prepare_tx(drv_data); + } + + /* Execute transaction */ + drv_data->block = 1; + writel(ctrl_reg, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL); + spin_unlock_irqrestore(&drv_data->lock, flags); + + mv64xxx_i2c_wait_for_completion(drv_data); + + return drv_data->rc; +} + +static bool +mv64xxx_i2c_valid_offload_sz(struct i2c_msg *msg) +{ + return msg->len <= 8 && msg->len >= 1; +} + +static bool +mv64xxx_i2c_can_offload(struct mv64xxx_i2c_data *drv_data) +{ + struct i2c_msg *msgs = drv_data->msgs; + int num = drv_data->num_msgs; + + return false; + + if (!drv_data->offload_enabled) + return false; + + /* + * We can offload a transaction consisting of a single + * message, as long as the message has a length between 1 and + * 8 bytes. + */ + if (num == 1 && mv64xxx_i2c_valid_offload_sz(msgs)) + return true; + + /* + * We can offload a transaction consisting of two messages, if + * the first is a write and a second is a read, and both have + * a length between 1 and 8 bytes. + */ + if (num == 2 && + mv64xxx_i2c_valid_offload_sz(msgs) && + mv64xxx_i2c_valid_offload_sz(msgs + 1) && + !(msgs[0].flags & I2C_M_RD) && + msgs[1].flags & I2C_M_RD) + return true; + + return false; +} + +/* + ***************************************************************************** + * + * I2C Core Support Routines (Interface to higher level I2C code) + * + ***************************************************************************** + */ +static u32 +mv64xxx_i2c_functionality(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SMBUS_EMUL; +} + +static int +mv64xxx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) +{ + struct mv64xxx_i2c_data *drv_data = i2c_get_adapdata(adap); + int rc, ret = num; + + BUG_ON(drv_data->msgs != NULL); + drv_data->msgs = msgs; + drv_data->num_msgs = num; + + if (mv64xxx_i2c_can_offload(drv_data)) + rc = mv64xxx_i2c_offload_xfer(drv_data); + else + rc = mv64xxx_i2c_execute_msg(drv_data, &msgs[0], num == 1); + + if (rc < 0) + ret = rc; + + drv_data->num_msgs = 0; + drv_data->msgs = NULL; + + return ret; +} + +static const struct i2c_algorithm mv64xxx_i2c_algo = { + .master_xfer = mv64xxx_i2c_xfer, + .functionality = mv64xxx_i2c_functionality, +}; + +/* + ***************************************************************************** + * + * Driver Interface & Early Init Routines + * + ***************************************************************************** + */ +static const struct of_device_id mv64xxx_i2c_of_match_table[] = { + { .compatible = "allwinner,sun4i-a10-i2c", .data = &mv64xxx_i2c_regs_sun4i}, + { .compatible = "allwinner,sun6i-a31-i2c", .data = &mv64xxx_i2c_regs_sun4i}, + { .compatible = "marvell,mv64xxx-i2c", .data = &mv64xxx_i2c_regs_mv64xxx}, + { .compatible = "marvell,mv78230-i2c", .data = &mv64xxx_i2c_regs_mv64xxx}, + { .compatible = "marvell,mv78230-a0-i2c", .data = &mv64xxx_i2c_regs_mv64xxx}, + {} +}; +MODULE_DEVICE_TABLE(of, mv64xxx_i2c_of_match_table); + +#ifdef CONFIG_OF +#ifdef CONFIG_HAVE_CLK +static int +mv64xxx_calc_freq(const int tclk, const int n, const int m) +{ + return tclk / (10 * (m + 1) * (2 << n)); +} + +static bool +mv64xxx_find_baud_factors(const u32 req_freq, const u32 tclk, u32 *best_n, + u32 *best_m) +{ + int freq, delta, best_delta = INT_MAX; + int m, n; + + for (n = 0; n <= 7; n++) + for (m = 0; m <= 15; m++) { + freq = mv64xxx_calc_freq(tclk, n, m); + delta = req_freq - freq; + if (delta >= 0 && delta < best_delta) { + *best_m = m; + *best_n = n; + best_delta = delta; + } + if (best_delta == 0) + return true; + } + if (best_delta == INT_MAX) + return false; + return true; +} +#endif /* CONFIG_HAVE_CLK */ + +static int +mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data, + struct device *dev) +{ + /* CLK is mandatory when using DT to describe the i2c bus. We + * need to know tclk in order to calculate bus clock + * factors. + */ +#if !defined(CONFIG_HAVE_CLK) + /* Have OF but no CLK */ + return -ENODEV; +#else + const struct of_device_id *device; + struct device_node *np = dev->of_node; + u32 bus_freq, tclk; + int rc = 0; + + if (IS_ERR(drv_data->clk)) { + rc = -ENODEV; + goto out; + } + tclk = clk_get_rate(drv_data->clk); + + if (of_property_read_u32(np, "clock-frequency", &bus_freq)) + bus_freq = 100000; /* 100kHz by default */ + + if (!mv64xxx_find_baud_factors(bus_freq, tclk, + &drv_data->freq_n, &drv_data->freq_m)) { + rc = -EINVAL; + goto out; + } + drv_data->irq = irq_of_parse_and_map(np, 0); + + drv_data->rstc = devm_reset_control_get_optional(dev, NULL); + if (IS_ERR(drv_data->rstc)) { + if (PTR_ERR(drv_data->rstc) == -EPROBE_DEFER) { + rc = -EPROBE_DEFER; + goto out; + } + } else { + reset_control_deassert(drv_data->rstc); + } + + /* Its not yet defined how timeouts will be specified in device tree. + * So hard code the value to 1 second. + */ + drv_data->adapter.timeout = HZ; + + device = of_match_device(mv64xxx_i2c_of_match_table, dev); + if (!device) + return -ENODEV; + + memcpy(&drv_data->reg_offsets, device->data, sizeof(drv_data->reg_offsets)); + + /* + * For controllers embedded in new SoCs activate the + * Transaction Generator support and the errata fix. + */ + if (of_device_is_compatible(np, "marvell,mv78230-i2c")) { + drv_data->offload_enabled = true; + drv_data->errata_delay = true; + } + + if (of_device_is_compatible(np, "marvell,mv78230-a0-i2c")) { + drv_data->offload_enabled = false; + drv_data->errata_delay = true; + } + + if (of_device_is_compatible(np, "allwinner,sun6i-a31-i2c")) + drv_data->irq_clear_inverted = true; + +out: + return rc; +#endif +} +#else /* CONFIG_OF */ +static int +mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data, + struct device *dev) +{ + return -ENODEV; +} +#endif /* CONFIG_OF */ + +static int +mv64xxx_i2c_probe(struct platform_device *pd) +{ + struct mv64xxx_i2c_data *drv_data; + struct mv64xxx_i2c_pdata *pdata = dev_get_platdata(&pd->dev); + struct resource *r; + int rc; + + if ((!pdata && !pd->dev.of_node)) + return -ENODEV; + + drv_data = devm_kzalloc(&pd->dev, sizeof(struct mv64xxx_i2c_data), + GFP_KERNEL); + if (!drv_data) + return -ENOMEM; + + r = platform_get_resource(pd, IORESOURCE_MEM, 0); + drv_data->reg_base = devm_ioremap_resource(&pd->dev, r); + if (IS_ERR(drv_data->reg_base)) + return PTR_ERR(drv_data->reg_base); + + strlcpy(drv_data->adapter.name, MV64XXX_I2C_CTLR_NAME " adapter", + sizeof(drv_data->adapter.name)); + + init_waitqueue_head(&drv_data->waitq); + spin_lock_init(&drv_data->lock); + +#if defined(CONFIG_HAVE_CLK) + /* Not all platforms have a clk */ + drv_data->clk = devm_clk_get(&pd->dev, NULL); + if (!IS_ERR(drv_data->clk)) { + clk_prepare(drv_data->clk); + clk_enable(drv_data->clk); + } +#endif + if (pdata) { + drv_data->freq_m = pdata->freq_m; + drv_data->freq_n = pdata->freq_n; + drv_data->irq = platform_get_irq(pd, 0); + drv_data->adapter.timeout = msecs_to_jiffies(pdata->timeout); + drv_data->offload_enabled = false; + memcpy(&drv_data->reg_offsets, &mv64xxx_i2c_regs_mv64xxx, sizeof(drv_data->reg_offsets)); + } else if (pd->dev.of_node) { + rc = mv64xxx_of_config(drv_data, &pd->dev); + if (rc) + goto exit_clk; + } + if (drv_data->irq < 0) { + rc = -ENXIO; + goto exit_reset; + } + + drv_data->adapter.dev.parent = &pd->dev; + drv_data->adapter.algo = &mv64xxx_i2c_algo; + drv_data->adapter.owner = THIS_MODULE; + drv_data->adapter.class = I2C_CLASS_DEPRECATED; + drv_data->adapter.nr = pd->id; + drv_data->adapter.dev.of_node = pd->dev.of_node; + platform_set_drvdata(pd, drv_data); + i2c_set_adapdata(&drv_data->adapter, drv_data); + + mv64xxx_i2c_hw_init(drv_data); + + rc = request_irq(drv_data->irq, mv64xxx_i2c_intr, 0, + MV64XXX_I2C_CTLR_NAME, drv_data); + if (rc) { + dev_err(&drv_data->adapter.dev, + "mv64xxx: Can't register intr handler irq%d: %d\n", + drv_data->irq, rc); + goto exit_reset; + } else if ((rc = i2c_add_numbered_adapter(&drv_data->adapter)) != 0) { + dev_err(&drv_data->adapter.dev, + "mv64xxx: Can't add i2c adapter, rc: %d\n", -rc); + goto exit_free_irq; + } + + return 0; + +exit_free_irq: + free_irq(drv_data->irq, drv_data); +exit_reset: + if (!IS_ERR_OR_NULL(drv_data->rstc)) + reset_control_assert(drv_data->rstc); +exit_clk: +#if defined(CONFIG_HAVE_CLK) + /* Not all platforms have a clk */ + if (!IS_ERR(drv_data->clk)) { + clk_disable(drv_data->clk); + clk_unprepare(drv_data->clk); + } +#endif + return rc; +} + +static int +mv64xxx_i2c_remove(struct platform_device *dev) +{ + struct mv64xxx_i2c_data *drv_data = platform_get_drvdata(dev); + + i2c_del_adapter(&drv_data->adapter); + free_irq(drv_data->irq, drv_data); + if (!IS_ERR_OR_NULL(drv_data->rstc)) + reset_control_assert(drv_data->rstc); +#if defined(CONFIG_HAVE_CLK) + /* Not all platforms have a clk */ + if (!IS_ERR(drv_data->clk)) { + clk_disable(drv_data->clk); + clk_unprepare(drv_data->clk); + } +#endif + + return 0; +} + +static struct platform_driver mv64xxx_i2c_driver = { + .probe = mv64xxx_i2c_probe, + .remove = mv64xxx_i2c_remove, + .driver = { + .name = MV64XXX_I2C_CTLR_NAME, + .of_match_table = mv64xxx_i2c_of_match_table, + }, +}; + +module_platform_driver(mv64xxx_i2c_driver); + +MODULE_AUTHOR("Mark A. Greer <mgreer@mvista.com>"); +MODULE_DESCRIPTION("Marvell mv64xxx host bridge i2c ctlr driver"); +MODULE_LICENSE("GPL"); |