diff options
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/Kconfig | 6 | ||||
| -rw-r--r-- | drivers/i2c/Makefile | 1 | ||||
| -rw-r--r-- | drivers/i2c/xilinx_xiic.c | 340 |
3 files changed, 347 insertions, 0 deletions
diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig index 1ef22e6bcde..536617115a2 100644 --- a/drivers/i2c/Kconfig +++ b/drivers/i2c/Kconfig @@ -450,6 +450,12 @@ config SYS_I2C_BUS_MAX help Define the maximum number of available I2C buses. +config SYS_I2C_XILINX_XIIC + bool "Xilinx AXI I2C driver" + depends on DM_I2C + help + Support for Xilinx AXI I2C controller. + config SYS_I2C_ZYNQ bool "Xilinx I2C driver" depends on ARCH_ZYNQMP || ARCH_ZYNQ diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile index d3637bcd8d6..ec2d1964c32 100644 --- a/drivers/i2c/Makefile +++ b/drivers/i2c/Makefile @@ -37,6 +37,7 @@ obj-$(CONFIG_SYS_I2C_TEGRA) += tegra_i2c.o obj-$(CONFIG_SYS_I2C_UNIPHIER) += i2c-uniphier.o obj-$(CONFIG_SYS_I2C_UNIPHIER_F) += i2c-uniphier-f.o obj-$(CONFIG_SYS_I2C_VERSATILE) += i2c-versatile.o +obj-$(CONFIG_SYS_I2C_XILINX_XIIC) += xilinx_xiic.o obj-$(CONFIG_SYS_I2C_ZYNQ) += zynq_i2c.o obj-$(CONFIG_TEGRA186_BPMP_I2C) += tegra186_bpmp_i2c.o diff --git a/drivers/i2c/xilinx_xiic.c b/drivers/i2c/xilinx_xiic.c new file mode 100644 index 00000000000..83114ed5103 --- /dev/null +++ b/drivers/i2c/xilinx_xiic.c @@ -0,0 +1,340 @@ +// 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> + +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 (pos == len && 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) +{ + int ret = 0; + + 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, +}; |