diff options
Diffstat (limited to 'drivers/i2c/kirkwood_i2c.c')
| -rw-r--r-- | drivers/i2c/kirkwood_i2c.c | 484 |
1 files changed, 484 insertions, 0 deletions
diff --git a/drivers/i2c/kirkwood_i2c.c b/drivers/i2c/kirkwood_i2c.c new file mode 100644 index 0000000..dd30499 --- /dev/null +++ b/drivers/i2c/kirkwood_i2c.c @@ -0,0 +1,484 @@ +/* + * Driver for the i2c controller on the Marvell line of host bridges + * (e.g, gt642[46]0, mv643[46]0, mv644[46]0, Orion SoC family), + * and Kirkwood family. + * + * Based on: + * 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. + * + * ported from Linux to u-boot + * (C) Copyright 2009 + * Heiko Schocher, DENX Software Engineering, hs@denx.de. + * + */ +#include <common.h> +#include <i2c.h> +#include <asm/arch/kirkwood.h> +#include <asm/errno.h> +#include <asm/io.h> + +DECLARE_GLOBAL_DATA_PTR; + +static unsigned int i2c_bus_num __attribute__ ((section (".data"))) = 0; +#if defined(CONFIG_I2C_MUX) +static unsigned int i2c_bus_num_mux __attribute__ ((section ("data"))) = 0; +#endif + +/* Register defines */ +#define KW_I2C_REG_SLAVE_ADDR 0x00 +#define KW_I2C_REG_DATA 0x04 +#define KW_I2C_REG_CONTROL 0x08 +#define KW_I2C_REG_STATUS 0x0c +#define KW_I2C_REG_BAUD 0x0c +#define KW_I2C_REG_EXT_SLAVE_ADDR 0x10 +#define KW_I2C_REG_SOFT_RESET 0x1c + +#define KW_I2C_REG_CONTROL_ACK 0x00000004 +#define KW_I2C_REG_CONTROL_IFLG 0x00000008 +#define KW_I2C_REG_CONTROL_STOP 0x00000010 +#define KW_I2C_REG_CONTROL_START 0x00000020 +#define KW_I2C_REG_CONTROL_TWSIEN 0x00000040 +#define KW_I2C_REG_CONTROL_INTEN 0x00000080 + +/* Ctlr status values */ +#define KW_I2C_STATUS_BUS_ERR 0x00 +#define KW_I2C_STATUS_MAST_START 0x08 +#define KW_I2C_STATUS_MAST_REPEAT_START 0x10 +#define KW_I2C_STATUS_MAST_WR_ADDR_ACK 0x18 +#define KW_I2C_STATUS_MAST_WR_ADDR_NO_ACK 0x20 +#define KW_I2C_STATUS_MAST_WR_ACK 0x28 +#define KW_I2C_STATUS_MAST_WR_NO_ACK 0x30 +#define KW_I2C_STATUS_MAST_LOST_ARB 0x38 +#define KW_I2C_STATUS_MAST_RD_ADDR_ACK 0x40 +#define KW_I2C_STATUS_MAST_RD_ADDR_NO_ACK 0x48 +#define KW_I2C_STATUS_MAST_RD_DATA_ACK 0x50 +#define KW_I2C_STATUS_MAST_RD_DATA_NO_ACK 0x58 +#define KW_I2C_STATUS_MAST_WR_ADDR_2_ACK 0xd0 +#define KW_I2C_STATUS_MAST_WR_ADDR_2_NO_ACK 0xd8 +#define KW_I2C_STATUS_MAST_RD_ADDR_2_ACK 0xe0 +#define KW_I2C_STATUS_MAST_RD_ADDR_2_NO_ACK 0xe8 +#define KW_I2C_STATUS_NO_STATUS 0xf8 + +/* Driver states */ +enum { + KW_I2C_STATE_INVALID, + KW_I2C_STATE_IDLE, + KW_I2C_STATE_WAITING_FOR_START_COND, + KW_I2C_STATE_WAITING_FOR_ADDR_1_ACK, + KW_I2C_STATE_WAITING_FOR_ADDR_2_ACK, + KW_I2C_STATE_WAITING_FOR_SLAVE_ACK, + KW_I2C_STATE_WAITING_FOR_SLAVE_DATA, +}; + +/* Driver actions */ +enum { + KW_I2C_ACTION_INVALID, + KW_I2C_ACTION_CONTINUE, + KW_I2C_ACTION_SEND_START, + KW_I2C_ACTION_SEND_ADDR_1, + KW_I2C_ACTION_SEND_ADDR_2, + KW_I2C_ACTION_SEND_DATA, + KW_I2C_ACTION_RCV_DATA, + KW_I2C_ACTION_RCV_DATA_STOP, + KW_I2C_ACTION_SEND_STOP, +}; + +/* defines to get compatible with Linux driver */ +#define IRQ_NONE 0x0 +#define IRQ_HANDLED 0x01 + +#define I2C_M_TEN 0x01 +#define I2C_M_RD 0x02 +#define I2C_M_REV_DIR_ADDR 0x04; + +struct i2c_msg { + u32 addr; + u32 flags; + u8 *buf; + u32 len; +}; + +struct kirkwood_i2c_data { + int irq; + u32 state; + u32 action; + u32 aborting; + u32 cntl_bits; + void *reg_base; + u32 reg_base_p; + u32 reg_size; + u32 addr1; + u32 addr2; + u32 bytes_left; + u32 byte_posn; + u32 block; + int rc; + u32 freq_m; + u32 freq_n; + struct i2c_msg *msg; +}; + +static struct kirkwood_i2c_data __drv_data __attribute__ ((section (".data"))); +static struct kirkwood_i2c_data *drv_data = &__drv_data; +static struct i2c_msg __i2c_msg __attribute__ ((section (".data"))); +static struct i2c_msg *kirkwood_i2c_msg = &__i2c_msg; + +/* + ***************************************************************************** + * + * Finite State Machine & Interrupt Routines + * + ***************************************************************************** + */ + +static inline int abs(int n) +{ + if(n >= 0) + return n; + else + return n * -1; +} + +static void kirkwood_calculate_speed(int speed) +{ + int calcspeed; + int diff; + int best_diff = CONFIG_SYS_TCLK; + int best_speed = 0; + int m, n; + int tmp[8] = {2, 4, 8, 16, 32, 64, 128, 256}; + + for (n = 0; n < 8; n++) { + for (m = 0; m < 16; m++) { + calcspeed = CONFIG_SYS_TCLK / (10 * (m + 1) * tmp[n]); + diff = abs((speed - calcspeed)); + if ( diff < best_diff) { + best_diff = diff; + best_speed = calcspeed; + drv_data->freq_m = m; + drv_data->freq_n = n; + } + } + } +} + +/* Reset hardware and initialize FSM */ +static void +kirkwood_i2c_hw_init(int speed, int slaveadd) +{ + drv_data->state = KW_I2C_STATE_IDLE; + + kirkwood_calculate_speed(speed); + writel(0, CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_SOFT_RESET); + writel((((drv_data->freq_m & 0xf) << 3) | (drv_data->freq_n & 0x7)), + CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_BAUD); + writel(slaveadd, CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_SLAVE_ADDR); + writel(0, CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_EXT_SLAVE_ADDR); + writel(KW_I2C_REG_CONTROL_TWSIEN | KW_I2C_REG_CONTROL_STOP, + CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL); +} + +static void +kirkwood_i2c_fsm(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 == KW_I2C_STATE_IDLE) { + drv_data->action = KW_I2C_ACTION_SEND_STOP; + return; + } + + /* The status from the ctlr [mostly] tells us what to do next */ + switch (status) { + /* Start condition interrupt */ + case KW_I2C_STATUS_MAST_START: /* 0x08 */ + case KW_I2C_STATUS_MAST_REPEAT_START: /* 0x10 */ + drv_data->action = KW_I2C_ACTION_SEND_ADDR_1; + drv_data->state = KW_I2C_STATE_WAITING_FOR_ADDR_1_ACK; + break; + + /* Performing a write */ + case KW_I2C_STATUS_MAST_WR_ADDR_ACK: /* 0x18 */ + if (drv_data->msg->flags & I2C_M_TEN) { + drv_data->action = KW_I2C_ACTION_SEND_ADDR_2; + drv_data->state = + KW_I2C_STATE_WAITING_FOR_ADDR_2_ACK; + break; + } + /* FALLTHRU */ + case KW_I2C_STATUS_MAST_WR_ADDR_2_ACK: /* 0xd0 */ + case KW_I2C_STATUS_MAST_WR_ACK: /* 0x28 */ + if ((drv_data->bytes_left == 0) + || (drv_data->aborting + && (drv_data->byte_posn != 0))) { + drv_data->action = KW_I2C_ACTION_SEND_STOP; + drv_data->state = KW_I2C_STATE_IDLE; + } else { + drv_data->action = KW_I2C_ACTION_SEND_DATA; + drv_data->state = + KW_I2C_STATE_WAITING_FOR_SLAVE_ACK; + drv_data->bytes_left--; + } + break; + + /* Performing a read */ + case KW_I2C_STATUS_MAST_RD_ADDR_ACK: /* 40 */ + if (drv_data->msg->flags & I2C_M_TEN) { + drv_data->action = KW_I2C_ACTION_SEND_ADDR_2; + drv_data->state = + KW_I2C_STATE_WAITING_FOR_ADDR_2_ACK; + break; + } + /* FALLTHRU */ + case KW_I2C_STATUS_MAST_RD_ADDR_2_ACK: /* 0xe0 */ + if (drv_data->bytes_left == 0) { + drv_data->action = KW_I2C_ACTION_SEND_STOP; + drv_data->state = KW_I2C_STATE_IDLE; + break; + } + /* FALLTHRU */ + case KW_I2C_STATUS_MAST_RD_DATA_ACK: /* 0x50 */ + if (status != KW_I2C_STATUS_MAST_RD_DATA_ACK) + drv_data->action = KW_I2C_ACTION_CONTINUE; + else { + drv_data->action = KW_I2C_ACTION_RCV_DATA; + drv_data->bytes_left--; + } + drv_data->state = KW_I2C_STATE_WAITING_FOR_SLAVE_DATA; + + if ((drv_data->bytes_left == 1) || drv_data->aborting) + drv_data->cntl_bits &= ~KW_I2C_REG_CONTROL_ACK; + break; + + case KW_I2C_STATUS_MAST_RD_DATA_NO_ACK: /* 0x58 */ + drv_data->action = KW_I2C_ACTION_RCV_DATA_STOP; + drv_data->state = KW_I2C_STATE_IDLE; + break; + + case KW_I2C_STATUS_MAST_WR_ADDR_NO_ACK: /* 0x20 */ + case KW_I2C_STATUS_MAST_WR_NO_ACK: /* 30 */ + case KW_I2C_STATUS_MAST_RD_ADDR_NO_ACK: /* 48 */ + /* Doesn't seem to be a device at other end */ + drv_data->action = KW_I2C_ACTION_SEND_STOP; + drv_data->state = KW_I2C_STATE_IDLE; + drv_data->rc = -ENODEV; + break; + + default: + printf("kirkwood_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 = KW_I2C_ACTION_SEND_STOP; + kirkwood_i2c_hw_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE); + drv_data->rc = -EIO; + } +} + +static void +kirkwood_i2c_do_action(void) +{ + switch(drv_data->action) { + case KW_I2C_ACTION_CONTINUE: + writel(drv_data->cntl_bits, + CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL); + break; + + case KW_I2C_ACTION_SEND_START: + writel(drv_data->cntl_bits | KW_I2C_REG_CONTROL_START, + CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL); + break; + + case KW_I2C_ACTION_SEND_ADDR_1: + writel(drv_data->addr1, + CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_DATA); + writel(drv_data->cntl_bits, + CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL); + break; + + case KW_I2C_ACTION_SEND_ADDR_2: + writel(drv_data->addr2, + CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_DATA); + writel(drv_data->cntl_bits, + CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL); + break; + + case KW_I2C_ACTION_SEND_DATA: + writel(drv_data->msg->buf[drv_data->byte_posn++], + CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_DATA); + writel(drv_data->cntl_bits, + CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL); + break; + + case KW_I2C_ACTION_RCV_DATA: + drv_data->msg->buf[drv_data->byte_posn++] = + readl(CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_DATA); + writel(drv_data->cntl_bits, + CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL); + break; + + case KW_I2C_ACTION_RCV_DATA_STOP: + drv_data->msg->buf[drv_data->byte_posn++] = + readl(CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_DATA); + drv_data->cntl_bits &= ~KW_I2C_REG_CONTROL_INTEN; + writel(drv_data->cntl_bits | KW_I2C_REG_CONTROL_STOP, + CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL); + drv_data->block = 0; + break; + + case KW_I2C_ACTION_INVALID: + default: + printf("kirkwood_i2c_do_action: Invalid action: %d\n", + drv_data->action); + drv_data->rc = -EIO; + /* FALLTHRU */ + case KW_I2C_ACTION_SEND_STOP: + drv_data->cntl_bits &= ~KW_I2C_REG_CONTROL_INTEN; + writel(drv_data->cntl_bits | KW_I2C_REG_CONTROL_STOP, + CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL); + drv_data->block = 0; + break; + } +} + +static int +kirkwood_i2c_intr(void) +{ + u32 status; + u32 ctrl; + int rc = IRQ_NONE; + + ctrl = readl(CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL); + while ((ctrl & KW_I2C_REG_CONTROL_IFLG) && + (drv_data->rc == 0)) { + status = readl(CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_STATUS); + kirkwood_i2c_fsm(status); + kirkwood_i2c_do_action(); + rc = IRQ_HANDLED; + ctrl = readl(CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL); + udelay(1000); + } + return rc; +} + +static void +kirkwood_i2c_doio(struct i2c_msg *msg) +{ + int ret; + + while ((drv_data->rc == 0) && (drv_data->state != KW_I2C_STATE_IDLE)) { + /* poll Status register */ + ret = kirkwood_i2c_intr(); + if (ret == IRQ_NONE) + udelay(10); + } +} + +static void +kirkwood_i2c_prepare_for_io(struct i2c_msg *msg) +{ + u32 dir = 0; + + drv_data->msg = msg; + drv_data->byte_posn = 0; + drv_data->bytes_left = msg->len; + drv_data->aborting = 0; + drv_data->rc = 0; + /* in u-boot we use no IRQs */ + drv_data->cntl_bits = KW_I2C_REG_CONTROL_ACK | KW_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 = ((u32)msg->addr & 0x7f) << 1 | dir; + drv_data->addr2 = 0; + } + /* OK, no start it (from kirkwood_i2c_execute_msg())*/ + drv_data->action = KW_I2C_ACTION_SEND_START; + drv_data->state = KW_I2C_STATE_WAITING_FOR_START_COND; + drv_data->block = 1; + kirkwood_i2c_do_action(); +} + +void +i2c_init(int speed, int slaveadd) +{ + kirkwood_i2c_hw_init(speed, slaveadd); +} + +int +i2c_read(u8 dev, uint addr, int alen, u8 *data, int length) +{ + kirkwood_i2c_msg->buf = data; + kirkwood_i2c_msg->len = length; + kirkwood_i2c_msg->addr = dev; + kirkwood_i2c_msg->flags = I2C_M_RD; + + kirkwood_i2c_prepare_for_io(kirkwood_i2c_msg); + kirkwood_i2c_doio(kirkwood_i2c_msg); + return drv_data->rc; +} + +int +i2c_write(u8 dev, uint addr, int alen, u8 *data, int length) +{ + kirkwood_i2c_msg->buf = data; + kirkwood_i2c_msg->len = length; + kirkwood_i2c_msg->addr = dev; + kirkwood_i2c_msg->flags = 0; + + kirkwood_i2c_prepare_for_io(kirkwood_i2c_msg); + kirkwood_i2c_doio(kirkwood_i2c_msg); + return drv_data->rc; +} + +int +i2c_probe(uchar chip) +{ + return i2c_read(chip, 0, 0, NULL, 0); +} + +int i2c_set_bus_num(unsigned int bus) +{ +#if defined(CONFIG_I2C_MUX) + if (bus < CONFIG_SYS_MAX_I2C_BUS) { + i2c_bus_num = bus; + } else { + int ret; + + ret = i2x_mux_select_mux(bus); + if (ret) + return ret; + i2c_bus_num = 0; + } + i2c_bus_num_mux = bus; +#else + if (bus > 0) { + return -1; + } + + i2c_bus_num = bus; +#endif + return 0; +} + +unsigned int i2c_get_bus_num(void) +{ +#if defined(CONFIG_I2C_MUX) + return i2c_bus_num_mux; +#else + return i2c_bus_num; +#endif +} + |