diff options
Diffstat (limited to 'arch/powerpc/boot/mv64x60_i2c.c')
| -rw-r--r-- | arch/powerpc/boot/mv64x60_i2c.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/arch/powerpc/boot/mv64x60_i2c.c b/arch/powerpc/boot/mv64x60_i2c.c new file mode 100644 index 000000000000..435fe8528680 --- /dev/null +++ b/arch/powerpc/boot/mv64x60_i2c.c @@ -0,0 +1,206 @@ +/* + * Bootloader version of the i2c driver for the MV64x60. + * + * Author: Dale Farnsworth <dfarnsworth@mvista.com> + * Maintained by: Mark A. Greer <mgreer@mvista.com> + * + * 2003, 2007 (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 <stdarg.h> +#include <stddef.h> +#include "types.h" +#include "elf.h" +#include "page.h" +#include "string.h" +#include "stdio.h" +#include "io.h" +#include "ops.h" +#include "mv64x60.h" + +extern void udelay(long); + +/* Register defines */ +#define MV64x60_I2C_REG_SLAVE_ADDR 0x00 +#define MV64x60_I2C_REG_DATA 0x04 +#define MV64x60_I2C_REG_CONTROL 0x08 +#define MV64x60_I2C_REG_STATUS 0x0c +#define MV64x60_I2C_REG_BAUD 0x0c +#define MV64x60_I2C_REG_EXT_SLAVE_ADDR 0x10 +#define MV64x60_I2C_REG_SOFT_RESET 0x1c + +#define MV64x60_I2C_CONTROL_ACK 0x04 +#define MV64x60_I2C_CONTROL_IFLG 0x08 +#define MV64x60_I2C_CONTROL_STOP 0x10 +#define MV64x60_I2C_CONTROL_START 0x20 +#define MV64x60_I2C_CONTROL_TWSIEN 0x40 +#define MV64x60_I2C_CONTROL_INTEN 0x80 + +#define MV64x60_I2C_STATUS_BUS_ERR 0x00 +#define MV64x60_I2C_STATUS_MAST_START 0x08 +#define MV64x60_I2C_STATUS_MAST_REPEAT_START 0x10 +#define MV64x60_I2C_STATUS_MAST_WR_ADDR_ACK 0x18 +#define MV64x60_I2C_STATUS_MAST_WR_ADDR_NO_ACK 0x20 +#define MV64x60_I2C_STATUS_MAST_WR_ACK 0x28 +#define MV64x60_I2C_STATUS_MAST_WR_NO_ACK 0x30 +#define MV64x60_I2C_STATUS_MAST_LOST_ARB 0x38 +#define MV64x60_I2C_STATUS_MAST_RD_ADDR_ACK 0x40 +#define MV64x60_I2C_STATUS_MAST_RD_ADDR_NO_ACK 0x48 +#define MV64x60_I2C_STATUS_MAST_RD_DATA_ACK 0x50 +#define MV64x60_I2C_STATUS_MAST_RD_DATA_NO_ACK 0x58 +#define MV64x60_I2C_STATUS_MAST_WR_ADDR_2_ACK 0xd0 +#define MV64x60_I2C_STATUS_MAST_WR_ADDR_2_NO_ACK 0xd8 +#define MV64x60_I2C_STATUS_MAST_RD_ADDR_2_ACK 0xe0 +#define MV64x60_I2C_STATUS_MAST_RD_ADDR_2_NO_ACK 0xe8 +#define MV64x60_I2C_STATUS_NO_STATUS 0xf8 + +static u8 *ctlr_base; + +static int mv64x60_i2c_wait_for_status(int wanted) +{ + int i; + int status; + + for (i=0; i<1000; i++) { + udelay(10); + status = in_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_STATUS)) + & 0xff; + if (status == wanted) + return status; + } + return -status; +} + +static int mv64x60_i2c_control(int control, int status) +{ + out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_CONTROL), control & 0xff); + return mv64x60_i2c_wait_for_status(status); +} + +static int mv64x60_i2c_read_byte(int control, int status) +{ + out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_CONTROL), control & 0xff); + if (mv64x60_i2c_wait_for_status(status) < 0) + return -1; + return in_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_DATA)) & 0xff; +} + +static int mv64x60_i2c_write_byte(int data, int control, int status) +{ + out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_DATA), data & 0xff); + out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_CONTROL), control & 0xff); + return mv64x60_i2c_wait_for_status(status); +} + +int mv64x60_i2c_read(u32 devaddr, u8 *buf, u32 offset, u32 offset_size, + u32 count) +{ + int i; + int data; + int control; + int status; + + if (ctlr_base == NULL) + return -1; + + /* send reset */ + out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_SOFT_RESET), 0); + out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_SLAVE_ADDR), 0); + out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_EXT_SLAVE_ADDR), 0); + out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_BAUD), (4 << 3) | 0x4); + + if (mv64x60_i2c_control(MV64x60_I2C_CONTROL_TWSIEN, + MV64x60_I2C_STATUS_NO_STATUS) < 0) + return -1; + + /* send start */ + control = MV64x60_I2C_CONTROL_START | MV64x60_I2C_CONTROL_TWSIEN; + status = MV64x60_I2C_STATUS_MAST_START; + if (mv64x60_i2c_control(control, status) < 0) + return -1; + + /* select device for writing */ + data = devaddr & ~0x1; + control = MV64x60_I2C_CONTROL_TWSIEN; + status = MV64x60_I2C_STATUS_MAST_WR_ADDR_ACK; + if (mv64x60_i2c_write_byte(data, control, status) < 0) + return -1; + + /* send offset of data */ + control = MV64x60_I2C_CONTROL_TWSIEN; + status = MV64x60_I2C_STATUS_MAST_WR_ACK; + if (offset_size > 1) { + if (mv64x60_i2c_write_byte(offset >> 8, control, status) < 0) + return -1; + } + if (mv64x60_i2c_write_byte(offset, control, status) < 0) + return -1; + + /* resend start */ + control = MV64x60_I2C_CONTROL_START | MV64x60_I2C_CONTROL_TWSIEN; + status = MV64x60_I2C_STATUS_MAST_REPEAT_START; + if (mv64x60_i2c_control(control, status) < 0) + return -1; + + /* select device for reading */ + data = devaddr | 0x1; + control = MV64x60_I2C_CONTROL_TWSIEN; + status = MV64x60_I2C_STATUS_MAST_RD_ADDR_ACK; + if (mv64x60_i2c_write_byte(data, control, status) < 0) + return -1; + + /* read all but last byte of data */ + control = MV64x60_I2C_CONTROL_ACK | MV64x60_I2C_CONTROL_TWSIEN; + status = MV64x60_I2C_STATUS_MAST_RD_DATA_ACK; + + for (i=1; i<count; i++) { + data = mv64x60_i2c_read_byte(control, status); + if (data < 0) { + printf("errors on iteration %d\n", i); + return -1; + } + *buf++ = data; + } + + /* read last byte of data */ + control = MV64x60_I2C_CONTROL_TWSIEN; + status = MV64x60_I2C_STATUS_MAST_RD_DATA_NO_ACK; + data = mv64x60_i2c_read_byte(control, status); + if (data < 0) + return -1; + *buf++ = data; + + /* send stop */ + control = MV64x60_I2C_CONTROL_STOP | MV64x60_I2C_CONTROL_TWSIEN; + status = MV64x60_I2C_STATUS_NO_STATUS; + if (mv64x60_i2c_control(control, status) < 0) + return -1; + + return count; +} + +int mv64x60_i2c_open(void) +{ + u32 v; + void *devp; + + devp = finddevice("/mv64x60/i2c"); + if (devp == NULL) + goto err_out; + if (getprop(devp, "virtual-reg", &v, sizeof(v)) != sizeof(v)) + goto err_out; + + ctlr_base = (u8 *)v; + return 0; + +err_out: + return -1; +} + +void mv64x60_i2c_close(void) +{ + ctlr_base = NULL; +} |