u-boot/drivers/i2c/xilinx_xiic.c
Simon Glass 336d4615f8 dm: core: Create a new header file for 'compat' features
At present dm/device.h includes the linux-compatible features. This
requires including linux/compat.h which in turn includes a lot of headers.
One of these is malloc.h which we thus end up including in every file in
U-Boot. Apart from the inefficiency of this, it is problematic for sandbox
which needs to use the system malloc() in some files.

Move the compatibility features into a separate header file.

Signed-off-by: Simon Glass <sjg@chromium.org>
2020-02-05 19:33:46 -07:00

353 lines
11 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Xilinx AXI I2C driver
*
* Copyright (C) 2018 Marek Vasut <marex@denx.de>
*
* Based on Linux 4.14.y i2c-xiic.c
* Copyright (c) 2002-2007 Xilinx Inc.
* Copyright (c) 2009-2010 Intel Corporation
*/
#include <common.h>
#include <clk.h>
#include <dm.h>
#include <i2c.h>
#include <wait_bit.h>
#include <asm/io.h>
#include <dm/device_compat.h>
struct xilinx_xiic_priv {
void __iomem *base;
struct clk clk;
};
#define XIIC_MSB_OFFSET 0
#define XIIC_REG_OFFSET (0x100+XIIC_MSB_OFFSET)
/*
* Register offsets in bytes from RegisterBase. Three is added to the
* base offset to access LSB (IBM style) of the word
*/
#define XIIC_CR_REG_OFFSET (0x00+XIIC_REG_OFFSET) /* Control Register */
#define XIIC_SR_REG_OFFSET (0x04+XIIC_REG_OFFSET) /* Status Register */
#define XIIC_DTR_REG_OFFSET (0x08+XIIC_REG_OFFSET) /* Data Tx Register */
#define XIIC_DRR_REG_OFFSET (0x0C+XIIC_REG_OFFSET) /* Data Rx Register */
#define XIIC_ADR_REG_OFFSET (0x10+XIIC_REG_OFFSET) /* Address Register */
#define XIIC_TFO_REG_OFFSET (0x14+XIIC_REG_OFFSET) /* Tx FIFO Occupancy */
#define XIIC_RFO_REG_OFFSET (0x18+XIIC_REG_OFFSET) /* Rx FIFO Occupancy */
#define XIIC_TBA_REG_OFFSET (0x1C+XIIC_REG_OFFSET) /* 10 Bit Address reg */
#define XIIC_RFD_REG_OFFSET (0x20+XIIC_REG_OFFSET) /* Rx FIFO Depth reg */
#define XIIC_GPO_REG_OFFSET (0x24+XIIC_REG_OFFSET) /* Output Register */
/* Control Register masks */
#define XIIC_CR_ENABLE_DEVICE_MASK 0x01 /* Device enable = 1 */
#define XIIC_CR_TX_FIFO_RESET_MASK 0x02 /* Transmit FIFO reset=1 */
#define XIIC_CR_MSMS_MASK 0x04 /* Master starts Txing=1 */
#define XIIC_CR_DIR_IS_TX_MASK 0x08 /* Dir of tx. Txing=1 */
#define XIIC_CR_NO_ACK_MASK 0x10 /* Tx Ack. NO ack = 1 */
#define XIIC_CR_REPEATED_START_MASK 0x20 /* Repeated start = 1 */
#define XIIC_CR_GENERAL_CALL_MASK 0x40 /* Gen Call enabled = 1 */
/* Status Register masks */
#define XIIC_SR_GEN_CALL_MASK 0x01 /* 1=a mstr issued a GC */
#define XIIC_SR_ADDR_AS_SLAVE_MASK 0x02 /* 1=when addr as slave */
#define XIIC_SR_BUS_BUSY_MASK 0x04 /* 1 = bus is busy */
#define XIIC_SR_MSTR_RDING_SLAVE_MASK 0x08 /* 1=Dir: mstr <-- slave */
#define XIIC_SR_TX_FIFO_FULL_MASK 0x10 /* 1 = Tx FIFO full */
#define XIIC_SR_RX_FIFO_FULL_MASK 0x20 /* 1 = Rx FIFO full */
#define XIIC_SR_RX_FIFO_EMPTY_MASK 0x40 /* 1 = Rx FIFO empty */
#define XIIC_SR_TX_FIFO_EMPTY_MASK 0x80 /* 1 = Tx FIFO empty */
/* Interrupt Status Register masks Interrupt occurs when... */
#define XIIC_INTR_ARB_LOST_MASK 0x01 /* 1 = arbitration lost */
#define XIIC_INTR_TX_ERROR_MASK 0x02 /* 1=Tx error/msg complete */
#define XIIC_INTR_TX_EMPTY_MASK 0x04 /* 1 = Tx FIFO/reg empty */
#define XIIC_INTR_RX_FULL_MASK 0x08 /* 1=Rx FIFO/reg=OCY level */
#define XIIC_INTR_BNB_MASK 0x10 /* 1 = Bus not busy */
#define XIIC_INTR_AAS_MASK 0x20 /* 1 = when addr as slave */
#define XIIC_INTR_NAAS_MASK 0x40 /* 1 = not addr as slave */
#define XIIC_INTR_TX_HALF_MASK 0x80 /* 1 = TX FIFO half empty */
/* The following constants specify the depth of the FIFOs */
#define IIC_RX_FIFO_DEPTH 16 /* Rx fifo capacity */
#define IIC_TX_FIFO_DEPTH 16 /* Tx fifo capacity */
/*
* Tx Fifo upper bit masks.
*/
#define XIIC_TX_DYN_START_MASK 0x0100 /* 1 = Set dynamic start */
#define XIIC_TX_DYN_STOP_MASK 0x0200 /* 1 = Set dynamic stop */
/*
* The following constants define the register offsets for the Interrupt
* registers. There are some holes in the memory map for reserved addresses
* to allow other registers to be added and still match the memory map of the
* interrupt controller registers
*/
#define XIIC_DGIER_OFFSET 0x1C /* Device Global Interrupt Enable Register */
#define XIIC_IISR_OFFSET 0x20 /* Interrupt Status Register */
#define XIIC_IIER_OFFSET 0x28 /* Interrupt Enable Register */
#define XIIC_RESETR_OFFSET 0x40 /* Reset Register */
#define XIIC_RESET_MASK 0xAUL
static u8 i2c_8bit_addr_from_flags(uint addr, u16 flags)
{
return (addr << 1) | (flags & I2C_M_RD ? 1 : 0);
}
static void xiic_irq_clr(struct xilinx_xiic_priv *priv, u32 mask)
{
u32 isr = readl(priv->base + XIIC_IISR_OFFSET);
writel(isr & mask, priv->base + XIIC_IISR_OFFSET);
}
static int xiic_read_rx(struct xilinx_xiic_priv *priv,
struct i2c_msg *msg, int nmsgs)
{
u8 bytes_in_fifo;
u32 pos = 0;
int i, ret;
while (pos < msg->len) {
ret = wait_for_bit_8(priv->base + XIIC_SR_REG_OFFSET,
XIIC_SR_RX_FIFO_EMPTY_MASK, false,
1000, true);
if (ret)
return ret;
bytes_in_fifo = readb(priv->base + XIIC_RFO_REG_OFFSET) + 1;
if (bytes_in_fifo > msg->len)
bytes_in_fifo = msg->len;
for (i = 0; i < bytes_in_fifo; i++) {
msg->buf[pos++] = readb(priv->base +
XIIC_DRR_REG_OFFSET);
}
}
return 0;
}
static int xiic_tx_fifo_space(struct xilinx_xiic_priv *priv)
{
/* return the actual space left in the FIFO */
return IIC_TX_FIFO_DEPTH - readb(priv->base + XIIC_TFO_REG_OFFSET) - 1;
}
static void xiic_fill_tx_fifo(struct xilinx_xiic_priv *priv,
struct i2c_msg *msg, int nmsgs)
{
u8 fifo_space = xiic_tx_fifo_space(priv);
int len = msg->len;
u32 pos = 0;
len = (len > fifo_space) ? fifo_space : len;
while (len--) {
u16 data = msg->buf[pos++];
if ((msg->len - pos == 0) && nmsgs == 1) {
/* last message in transfer -> STOP */
data |= XIIC_TX_DYN_STOP_MASK;
}
writew(data, priv->base + XIIC_DTR_REG_OFFSET);
}
}
static void xilinx_xiic_set_addr(struct udevice *dev, u8 addr,
u16 flags, u32 len, u32 nmsgs)
{
struct xilinx_xiic_priv *priv = dev_get_priv(dev);
xiic_irq_clr(priv, XIIC_INTR_TX_ERROR_MASK);
if (!(flags & I2C_M_NOSTART)) {
/* write the address */
u16 data = i2c_8bit_addr_from_flags(addr, flags) |
XIIC_TX_DYN_START_MASK;
if (nmsgs == 1 && len == 0)
/* no data and last message -> add STOP */
data |= XIIC_TX_DYN_STOP_MASK;
writew(data, priv->base + XIIC_DTR_REG_OFFSET);
}
}
static int xilinx_xiic_read_common(struct udevice *dev, struct i2c_msg *msg,
u32 nmsgs)
{
struct xilinx_xiic_priv *priv = dev_get_priv(dev);
u8 rx_watermark;
/* Clear and enable Rx full interrupt. */
xiic_irq_clr(priv, XIIC_INTR_RX_FULL_MASK | XIIC_INTR_TX_ERROR_MASK);
/* we want to get all but last byte, because the TX_ERROR IRQ is used
* to inidicate error ACK on the address, and negative ack on the last
* received byte, so to not mix them receive all but last.
* In the case where there is only one byte to receive
* we can check if ERROR and RX full is set at the same time
*/
rx_watermark = msg->len;
if (rx_watermark > IIC_RX_FIFO_DEPTH)
rx_watermark = IIC_RX_FIFO_DEPTH;
writeb(rx_watermark - 1, priv->base + XIIC_RFD_REG_OFFSET);
xilinx_xiic_set_addr(dev, msg->addr, msg->flags, msg->len, nmsgs);
xiic_irq_clr(priv, XIIC_INTR_BNB_MASK);
writew((msg->len & 0xff) | ((nmsgs == 1) ? XIIC_TX_DYN_STOP_MASK : 0),
priv->base + XIIC_DTR_REG_OFFSET);
if (nmsgs == 1)
/* very last, enable bus not busy as well */
xiic_irq_clr(priv, XIIC_INTR_BNB_MASK);
return xiic_read_rx(priv, msg, nmsgs);
}
static int xilinx_xiic_write_common(struct udevice *dev, struct i2c_msg *msg,
int nmsgs)
{
struct xilinx_xiic_priv *priv = dev_get_priv(dev);
int ret;
xilinx_xiic_set_addr(dev, msg->addr, msg->flags, msg->len, nmsgs);
xiic_fill_tx_fifo(priv, msg, nmsgs);
ret = wait_for_bit_8(priv->base + XIIC_SR_REG_OFFSET,
XIIC_SR_TX_FIFO_EMPTY_MASK, false, 1000, true);
if (ret)
return ret;
/* Clear any pending Tx empty, Tx Error and then enable them. */
xiic_irq_clr(priv, XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_ERROR_MASK |
XIIC_INTR_BNB_MASK);
return 0;
}
static void xiic_clear_rx_fifo(struct xilinx_xiic_priv *priv)
{
u8 sr;
for (sr = readb(priv->base + XIIC_SR_REG_OFFSET);
!(sr & XIIC_SR_RX_FIFO_EMPTY_MASK);
sr = readb(priv->base + XIIC_SR_REG_OFFSET))
readb(priv->base + XIIC_DRR_REG_OFFSET);
}
static void xiic_reinit(struct xilinx_xiic_priv *priv)
{
writel(XIIC_RESET_MASK, priv->base + XIIC_RESETR_OFFSET);
/* Set receive Fifo depth to maximum (zero based). */
writeb(IIC_RX_FIFO_DEPTH - 1, priv->base + XIIC_RFD_REG_OFFSET);
/* Reset Tx Fifo. */
writeb(XIIC_CR_TX_FIFO_RESET_MASK, priv->base + XIIC_CR_REG_OFFSET);
/* Enable IIC Device, remove Tx Fifo reset & disable general call. */
writeb(XIIC_CR_ENABLE_DEVICE_MASK, priv->base + XIIC_CR_REG_OFFSET);
/* make sure RX fifo is empty */
xiic_clear_rx_fifo(priv);
/* Disable interrupts */
writel(0, priv->base + XIIC_DGIER_OFFSET);
xiic_irq_clr(priv, XIIC_INTR_ARB_LOST_MASK);
}
static int xilinx_xiic_xfer(struct udevice *dev, struct i2c_msg *msg, int nmsgs)
{
struct xilinx_xiic_priv *priv = dev_get_priv(dev);
int ret = 0;
ret = wait_for_bit_8(priv->base + XIIC_SR_REG_OFFSET,
XIIC_SR_BUS_BUSY_MASK, false, 1000, true);
if (ret == -ETIMEDOUT)
dev_err(dev, "timeout waiting for bus not busy condition\n");
if (ret)
return ret;
xiic_reinit(priv);
for (; nmsgs > 0; nmsgs--, msg++) {
if (msg->flags & I2C_M_RD)
ret = xilinx_xiic_read_common(dev, msg, nmsgs);
else
ret = xilinx_xiic_write_common(dev, msg, nmsgs);
if (ret)
return -EREMOTEIO;
}
return ret;
}
static int xilinx_xiic_probe_chip(struct udevice *dev, uint addr, uint flags)
{
struct xilinx_xiic_priv *priv = dev_get_priv(dev);
u32 reg;
int ret;
xiic_reinit(priv);
xilinx_xiic_set_addr(dev, addr, 0, 0, 1);
ret = wait_for_bit_8(priv->base + XIIC_SR_REG_OFFSET,
XIIC_SR_BUS_BUSY_MASK, false, 1000, true);
if (ret)
return ret;
reg = readl(priv->base + XIIC_IISR_OFFSET);
if (reg & XIIC_INTR_TX_ERROR_MASK)
return -ENODEV;
return 0;
}
static int xilinx_xiic_set_speed(struct udevice *dev, uint speed)
{
return 0;
}
static int xilinx_xiic_probe(struct udevice *dev)
{
struct xilinx_xiic_priv *priv = dev_get_priv(dev);
priv->base = dev_read_addr_ptr(dev);
writel(XIIC_CR_TX_FIFO_RESET_MASK, priv->base + XIIC_CR_REG_OFFSET);
xiic_reinit(priv);
return 0;
}
static const struct dm_i2c_ops xilinx_xiic_ops = {
.xfer = xilinx_xiic_xfer,
.probe_chip = xilinx_xiic_probe_chip,
.set_bus_speed = xilinx_xiic_set_speed,
};
static const struct udevice_id xilinx_xiic_ids[] = {
{ .compatible = "xlnx,xps-iic-2.00.a" },
{ }
};
U_BOOT_DRIVER(xilinx_xiic) = {
.name = "xilinx_axi_i2c",
.id = UCLASS_I2C,
.of_match = xilinx_xiic_ids,
.probe = xilinx_xiic_probe,
.priv_auto_alloc_size = sizeof(struct xilinx_xiic_priv),
.ops = &xilinx_xiic_ops,
};