diff options
Diffstat (limited to 'drivers/i2c/zynq_i2c.c')
| -rw-r--r-- | drivers/i2c/zynq_i2c.c | 306 |
1 files changed, 306 insertions, 0 deletions
diff --git a/drivers/i2c/zynq_i2c.c b/drivers/i2c/zynq_i2c.c new file mode 100644 index 000000000..ec49660cf --- /dev/null +++ b/drivers/i2c/zynq_i2c.c @@ -0,0 +1,306 @@ +/* + * 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 + * + * See file CREDITS for list of people who contributed to this + * project. + * + * 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., 51 Franklin Street, Fifth Floor, Boston, + * MA 02110-1301 USA + */ + +#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'. */ +void i2c_init(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. + */ +int i2c_probe(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. + */ +int i2c_read(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_RW | + ZYNQ_I2C_CONTROL_HOLD); + writel(0xFF, &zynq_i2c->interrupt_status); + while (alen--) + writel(addr >> (8*alen), &zynq_i2c->data); + writel(dev, &zynq_i2c->address); + + /* 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. + */ +int i2c_write(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); + while (alen--) + writel(addr >> (8*alen), &zynq_i2c->data); + /* Start the tranfer */ + writel(dev, &zynq_i2c->address); + 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; +} + +int i2c_set_bus_num(unsigned int bus) +{ + /* Only support bus 0 */ + if (bus > 0) + return -1; + return 0; +} + +unsigned int i2c_get_bus_num(void) +{ + /* Only support bus 0 */ + return 0; +} |