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/*
* Driver for the Zynq-7000 PS I2C controller
* IP from Cadence (ID T-CS-PE-0007-100, Version R1p10f2)
*
* Author: Joe Hershberger <joe.hershberger@ni.com>
* Copyright (c) 2012 Joe Hershberger.
*
* Copyright (c) 2012-2013 Xilinx, Michal Simek
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <asm/io.h>
#include <i2c.h>
#include <asm/errno.h>
#include <asm/arch/hardware.h>
/* i2c register set */
struct zynq_i2c_registers {
u32 control;
u32 status;
u32 address;
u32 data;
u32 interrupt_status;
u32 transfer_size;
u32 slave_mon_pause;
u32 time_out;
u32 interrupt_mask;
u32 interrupt_enable;
u32 interrupt_disable;
};
/* Control register fields */
#define ZYNQ_I2C_CONTROL_RW 0x00000001
#define ZYNQ_I2C_CONTROL_MS 0x00000002
#define ZYNQ_I2C_CONTROL_NEA 0x00000004
#define ZYNQ_I2C_CONTROL_ACKEN 0x00000008
#define ZYNQ_I2C_CONTROL_HOLD 0x00000010
#define ZYNQ_I2C_CONTROL_SLVMON 0x00000020
#define ZYNQ_I2C_CONTROL_CLR_FIFO 0x00000040
#define ZYNQ_I2C_CONTROL_DIV_B_SHIFT 8
#define ZYNQ_I2C_CONTROL_DIV_B_MASK 0x00003F00
#define ZYNQ_I2C_CONTROL_DIV_A_SHIFT 14
#define ZYNQ_I2C_CONTROL_DIV_A_MASK 0x0000C000
/* Status register values */
#define ZYNQ_I2C_STATUS_RXDV 0x00000020
#define ZYNQ_I2C_STATUS_TXDV 0x00000040
#define ZYNQ_I2C_STATUS_RXOVF 0x00000080
#define ZYNQ_I2C_STATUS_BA 0x00000100
/* Interrupt register fields */
#define ZYNQ_I2C_INTERRUPT_COMP 0x00000001
#define ZYNQ_I2C_INTERRUPT_DATA 0x00000002
#define ZYNQ_I2C_INTERRUPT_NACK 0x00000004
#define ZYNQ_I2C_INTERRUPT_TO 0x00000008
#define ZYNQ_I2C_INTERRUPT_SLVRDY 0x00000010
#define ZYNQ_I2C_INTERRUPT_RXOVF 0x00000020
#define ZYNQ_I2C_INTERRUPT_TXOVF 0x00000040
#define ZYNQ_I2C_INTERRUPT_RXUNF 0x00000080
#define ZYNQ_I2C_INTERRUPT_ARBLOST 0x00000200
#define ZYNQ_I2C_FIFO_DEPTH 16
#define ZYNQ_I2C_TRANSFERT_SIZE_MAX 255 /* Controller transfer limit */
#if defined(CONFIG_ZYNQ_I2C0)
# define ZYNQ_I2C_BASE ZYNQ_I2C_BASEADDR0
#else
# define ZYNQ_I2C_BASE ZYNQ_I2C_BASEADDR1
#endif
static struct zynq_i2c_registers *zynq_i2c =
(struct zynq_i2c_registers *)ZYNQ_I2C_BASE;
/* I2C init called by cmd_i2c when doing 'i2c reset'. */
static void zynq_i2c_init(struct i2c_adapter *adap, int requested_speed,
int slaveadd)
{
/* 111MHz / ( (3 * 17) * 22 ) = ~100KHz */
writel((16 << ZYNQ_I2C_CONTROL_DIV_B_SHIFT) |
(2 << ZYNQ_I2C_CONTROL_DIV_A_SHIFT), &zynq_i2c->control);
/* Enable master mode, ack, and 7-bit addressing */
setbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_MS |
ZYNQ_I2C_CONTROL_ACKEN | ZYNQ_I2C_CONTROL_NEA);
}
#ifdef DEBUG
static void zynq_i2c_debug_status(void)
{
int int_status;
int status;
int_status = readl(&zynq_i2c->interrupt_status);
status = readl(&zynq_i2c->status);
if (int_status || status) {
debug("Status: ");
if (int_status & ZYNQ_I2C_INTERRUPT_COMP)
debug("COMP ");
if (int_status & ZYNQ_I2C_INTERRUPT_DATA)
debug("DATA ");
if (int_status & ZYNQ_I2C_INTERRUPT_NACK)
debug("NACK ");
if (int_status & ZYNQ_I2C_INTERRUPT_TO)
debug("TO ");
if (int_status & ZYNQ_I2C_INTERRUPT_SLVRDY)
debug("SLVRDY ");
if (int_status & ZYNQ_I2C_INTERRUPT_RXOVF)
debug("RXOVF ");
if (int_status & ZYNQ_I2C_INTERRUPT_TXOVF)
debug("TXOVF ");
if (int_status & ZYNQ_I2C_INTERRUPT_RXUNF)
debug("RXUNF ");
if (int_status & ZYNQ_I2C_INTERRUPT_ARBLOST)
debug("ARBLOST ");
if (status & ZYNQ_I2C_STATUS_RXDV)
debug("RXDV ");
if (status & ZYNQ_I2C_STATUS_TXDV)
debug("TXDV ");
if (status & ZYNQ_I2C_STATUS_RXOVF)
debug("RXOVF ");
if (status & ZYNQ_I2C_STATUS_BA)
debug("BA ");
debug("TS%d ", readl(&zynq_i2c->transfer_size));
debug("\n");
}
}
#endif
/* Wait for an interrupt */
static u32 zynq_i2c_wait(u32 mask)
{
int timeout, int_status;
for (timeout = 0; timeout < 100; timeout++) {
udelay(100);
int_status = readl(&zynq_i2c->interrupt_status);
if (int_status & mask)
break;
}
#ifdef DEBUG
zynq_i2c_debug_status();
#endif
/* Clear interrupt status flags */
writel(int_status & mask, &zynq_i2c->interrupt_status);
return int_status & mask;
}
/*
* I2C probe called by cmd_i2c when doing 'i2c probe'.
* Begin read, nak data byte, end.
*/
static int zynq_i2c_probe(struct i2c_adapter *adap, u8 dev)
{
/* Attempt to read a byte */
setbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_CLR_FIFO |
ZYNQ_I2C_CONTROL_RW);
clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
writel(0xFF, &zynq_i2c->interrupt_status);
writel(dev, &zynq_i2c->address);
writel(1, &zynq_i2c->transfer_size);
return (zynq_i2c_wait(ZYNQ_I2C_INTERRUPT_COMP |
ZYNQ_I2C_INTERRUPT_NACK) &
ZYNQ_I2C_INTERRUPT_COMP) ? 0 : -ETIMEDOUT;
}
/*
* I2C read called by cmd_i2c when doing 'i2c read' and by cmd_eeprom.c
* Begin write, send address byte(s), begin read, receive data bytes, end.
*/
static int zynq_i2c_read(struct i2c_adapter *adap, u8 dev, uint addr,
int alen, u8 *data, int length)
{
u32 status;
u32 i = 0;
u8 *cur_data = data;
/* Check the hardware can handle the requested bytes */
if ((length < 0) || (length > ZYNQ_I2C_TRANSFERT_SIZE_MAX))
return -EINVAL;
/* Write the register address */
setbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_CLR_FIFO |
ZYNQ_I2C_CONTROL_HOLD);
/*
* Temporarily disable restart (by clearing hold)
* It doesn't seem to work.
*/
clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
writel(0xFF, &zynq_i2c->interrupt_status);
if (alen) {
clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_RW);
writel(dev, &zynq_i2c->address);
while (alen--)
writel(addr >> (8 * alen), &zynq_i2c->data);
/* Wait for the address to be sent */
if (!zynq_i2c_wait(ZYNQ_I2C_INTERRUPT_COMP)) {
/* Release the bus */
clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
return -ETIMEDOUT;
}
debug("Device acked address\n");
}
setbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_CLR_FIFO |
ZYNQ_I2C_CONTROL_RW);
/* Start reading data */
writel(dev, &zynq_i2c->address);
writel(length, &zynq_i2c->transfer_size);
/* Wait for data */
do {
status = zynq_i2c_wait(ZYNQ_I2C_INTERRUPT_COMP |
ZYNQ_I2C_INTERRUPT_DATA);
if (!status) {
/* Release the bus */
clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
return -ETIMEDOUT;
}
debug("Read %d bytes\n",
length - readl(&zynq_i2c->transfer_size));
for (; i < length - readl(&zynq_i2c->transfer_size); i++)
*(cur_data++) = readl(&zynq_i2c->data);
} while (readl(&zynq_i2c->transfer_size) != 0);
/* All done... release the bus */
clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
#ifdef DEBUG
zynq_i2c_debug_status();
#endif
return 0;
}
/*
* I2C write called by cmd_i2c when doing 'i2c write' and by cmd_eeprom.c
* Begin write, send address byte(s), send data bytes, end.
*/
static int zynq_i2c_write(struct i2c_adapter *adap, u8 dev, uint addr,
int alen, u8 *data, int length)
{
u8 *cur_data = data;
/* Write the register address */
setbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_CLR_FIFO |
ZYNQ_I2C_CONTROL_HOLD);
clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_RW);
writel(0xFF, &zynq_i2c->interrupt_status);
writel(dev, &zynq_i2c->address);
if (alen) {
while (alen--)
writel(addr >> (8 * alen), &zynq_i2c->data);
/* Start the tranfer */
if (!zynq_i2c_wait(ZYNQ_I2C_INTERRUPT_COMP)) {
/* Release the bus */
clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
return -ETIMEDOUT;
}
debug("Device acked address\n");
}
while (length--) {
writel(*(cur_data++), &zynq_i2c->data);
if (readl(&zynq_i2c->transfer_size) == ZYNQ_I2C_FIFO_DEPTH) {
if (!zynq_i2c_wait(ZYNQ_I2C_INTERRUPT_COMP)) {
/* Release the bus */
clrbits_le32(&zynq_i2c->control,
ZYNQ_I2C_CONTROL_HOLD);
return -ETIMEDOUT;
}
}
}
/* All done... release the bus */
clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
/* Wait for the address and data to be sent */
if (!zynq_i2c_wait(ZYNQ_I2C_INTERRUPT_COMP))
return -ETIMEDOUT;
return 0;
}
static unsigned int zynq_i2c_set_bus_speed(struct i2c_adapter *adap,
unsigned int speed)
{
if (speed != 1000000)
return -EINVAL;
return 0;
}
U_BOOT_I2C_ADAP_COMPLETE(zynq_0, zynq_i2c_init, zynq_i2c_probe, zynq_i2c_read,
zynq_i2c_write, zynq_i2c_set_bus_speed,
CONFIG_SYS_I2C_ZYNQ_SPEED, CONFIG_SYS_I2C_ZYNQ_SLAVE,
0)
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