[PATCH v2 10/25] i2c: add Tegra driver
Lucas Stach
dev at lynxeye.de
Wed May 14 13:45:37 PDT 2014
Signed-off-by: Lucas Stach <dev at lynxeye.de>
---
v2:
- remove debug clk_enable
- remove xzalloc check
- remove confusing if statement
---
drivers/i2c/busses/Kconfig | 4 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-tegra.c | 699 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 704 insertions(+)
create mode 100644 drivers/i2c/busses/i2c-tegra.c
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 68d9b469e86f..370abb0c2eb1 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -20,6 +20,10 @@ config I2C_OMAP
bool "OMAP I2C Master driver"
depends on ARCH_OMAP
+config I2C_TEGRA
+ bool "Tegra I2C master driver"
+ depends on ARCH_TEGRA
+
config I2C_VERSATILE
tristate "ARM Versatile/Realview I2C bus support"
depends on ARCH_VERSATILE
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index a30f9b87e3ba..9823d1bd3600 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -1,4 +1,5 @@
obj-$(CONFIG_I2C_GPIO) += i2c-gpio.o
obj-$(CONFIG_I2C_IMX) += i2c-imx.o
obj-$(CONFIG_I2C_OMAP) += i2c-omap.o
+obj-$(CONFIG_I2C_TEGRA) += i2c-tegra.o
obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o
diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
new file mode 100644
index 000000000000..c52da18b5792
--- /dev/null
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -0,0 +1,699 @@
+/*
+ * Copyright (C) 2014 Lucas Stach <l.stach at pengutronix.de>
+ *
+ * Partly based on code Copyright (C) 2010 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+#include <common.h>
+#include <clock.h>
+#include <init.h>
+#include <io.h>
+#include <malloc.h>
+#include <i2c/i2c.h>
+#include <linux/kernel.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/reset.h>
+
+#include <asm/unaligned.h>
+
+#define TEGRA_I2C_TIMEOUT (msecs_to_jiffies(1000))
+#define BYTES_PER_FIFO_WORD 4
+
+#define I2C_CNFG 0x000
+#define I2C_CNFG_DEBOUNCE_CNT_SHIFT 12
+#define I2C_CNFG_PACKET_MODE_EN (1<<10)
+#define I2C_CNFG_NEW_MASTER_FSM (1<<11)
+#define I2C_STATUS 0x01C
+#define I2C_SL_CNFG 0x020
+#define I2C_SL_CNFG_NACK (1<<1)
+#define I2C_SL_CNFG_NEWSL (1<<2)
+#define I2C_SL_ADDR1 0x02c
+#define I2C_SL_ADDR2 0x030
+#define I2C_TX_FIFO 0x050
+#define I2C_RX_FIFO 0x054
+#define I2C_PACKET_TRANSFER_STATUS 0x058
+#define I2C_FIFO_CONTROL 0x05c
+#define I2C_FIFO_CONTROL_TX_FLUSH (1<<1)
+#define I2C_FIFO_CONTROL_RX_FLUSH (1<<0)
+#define I2C_FIFO_CONTROL_TX_TRIG_SHIFT 5
+#define I2C_FIFO_CONTROL_RX_TRIG_SHIFT 2
+#define I2C_FIFO_STATUS 0x060
+#define I2C_FIFO_STATUS_TX_MASK 0xF0
+#define I2C_FIFO_STATUS_TX_SHIFT 4
+#define I2C_FIFO_STATUS_RX_MASK 0x0F
+#define I2C_FIFO_STATUS_RX_SHIFT 0
+#define I2C_INT_MASK 0x064
+#define I2C_INT_STATUS 0x068
+#define I2C_INT_PACKET_XFER_COMPLETE (1<<7)
+#define I2C_INT_ALL_PACKETS_XFER_COMPLETE (1<<6)
+#define I2C_INT_TX_FIFO_OVERFLOW (1<<5)
+#define I2C_INT_RX_FIFO_UNDERFLOW (1<<4)
+#define I2C_INT_NO_ACK (1<<3)
+#define I2C_INT_ARBITRATION_LOST (1<<2)
+#define I2C_INT_TX_FIFO_DATA_REQ (1<<1)
+#define I2C_INT_RX_FIFO_DATA_REQ (1<<0)
+#define I2C_CLK_DIVISOR 0x06c
+#define I2C_CLK_DIVISOR_STD_FAST_MODE_SHIFT 16
+#define I2C_CLK_MULTIPLIER_STD_FAST_MODE 8
+
+#define DVC_CTRL_REG1 0x000
+#define DVC_CTRL_REG1_INTR_EN (1<<10)
+#define DVC_CTRL_REG2 0x004
+#define DVC_CTRL_REG3 0x008
+#define DVC_CTRL_REG3_SW_PROG (1<<26)
+#define DVC_CTRL_REG3_I2C_DONE_INTR_EN (1<<30)
+#define DVC_STATUS 0x00c
+#define DVC_STATUS_I2C_DONE_INTR (1<<30)
+
+#define I2C_ERR_NONE 0x00
+#define I2C_ERR_NO_ACK 0x01
+#define I2C_ERR_ARBITRATION_LOST 0x02
+#define I2C_ERR_UNKNOWN_INTERRUPT 0x04
+
+#define PACKET_HEADER0_HEADER_SIZE_SHIFT 28
+#define PACKET_HEADER0_PACKET_ID_SHIFT 16
+#define PACKET_HEADER0_CONT_ID_SHIFT 12
+#define PACKET_HEADER0_PROTOCOL_I2C (1<<4)
+
+#define I2C_HEADER_HIGHSPEED_MODE (1<<22)
+#define I2C_HEADER_CONT_ON_NAK (1<<21)
+#define I2C_HEADER_SEND_START_BYTE (1<<20)
+#define I2C_HEADER_READ (1<<19)
+#define I2C_HEADER_10BIT_ADDR (1<<18)
+#define I2C_HEADER_IE_ENABLE (1<<17)
+#define I2C_HEADER_REPEAT_START (1<<16)
+#define I2C_HEADER_CONTINUE_XFER (1<<15)
+#define I2C_HEADER_MASTER_ADDR_SHIFT 12
+#define I2C_HEADER_SLAVE_ADDR_SHIFT 1
+/*
+ * msg_end_type: The bus control which need to be send at end of transfer.
+ * @MSG_END_STOP: Send stop pulse at end of transfer.
+ * @MSG_END_REPEAT_START: Send repeat start at end of transfer.
+ * @MSG_END_CONTINUE: The following on message is coming and so do not send
+ * stop or repeat start.
+ */
+enum msg_end_type {
+ MSG_END_STOP,
+ MSG_END_REPEAT_START,
+ MSG_END_CONTINUE,
+};
+
+/**
+ * struct tegra_i2c_hw_feature : Different HW support on Tegra
+ * @has_continue_xfer_support: Continue transfer supports.
+ * @has_per_pkt_xfer_complete_irq: Has enable/disable capability for transfer
+ * complete interrupt per packet basis.
+ * @has_single_clk_source: The i2c controller has single clock source. Tegra30
+ * and earlier Socs has two clock sources i.e. div-clk and
+ * fast-clk.
+ * @clk_divisor_hs_mode: Clock divisor in HS mode.
+ * @clk_divisor_std_fast_mode: Clock divisor in standard/fast mode. It is
+ * applicable if there is no fast clock source i.e. single clock
+ * source.
+ */
+
+struct tegra_i2c_hw_feature {
+ bool has_continue_xfer_support;
+ bool has_per_pkt_xfer_complete_irq;
+ bool has_single_clk_source;
+ int clk_divisor_hs_mode;
+ int clk_divisor_std_fast_mode;
+};
+
+/**
+ * struct tegra_i2c_dev - per device i2c context
+ * @dev: device reference for power management
+ * @hw: Tegra i2c hw feature.
+ * @adapter: core i2c layer adapter information
+ * @div_clk: clock reference for div clock of i2c controller.
+ * @fast_clk: clock reference for fast clock of i2c controller.
+ * @base: ioremapped registers cookie
+ * @is_dvc: identifies the DVC i2c controller, has a different register layout
+ * @msg_err: error code for completed message
+ * @msg_buf: pointer to current message data
+ * @msg_buf_remaining: size of unsent data in the message buffer
+ * @msg_read: identifies read transfers
+ * @bus_clk_rate: current i2c bus clock rate
+ */
+struct tegra_i2c_dev {
+ struct device_d *dev;
+ const struct tegra_i2c_hw_feature *hw;
+ struct i2c_adapter adapter;
+ struct clk *div_clk;
+ struct clk *fast_clk;
+ struct reset_control *rst;
+ void __iomem *base;
+ int is_dvc;
+ int msg_err;
+ u8 *msg_buf;
+ size_t msg_buf_remaining;
+ int msg_read;
+ u32 bus_clk_rate;
+};
+#define to_tegra_i2c_dev(a) container_of(a, struct tegra_i2c_dev, adapter)
+
+static void dvc_writel(struct tegra_i2c_dev *i2c_dev, u32 val, unsigned long reg)
+{
+ writel(val, i2c_dev->base + reg);
+}
+
+static u32 dvc_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
+{
+ return readl(i2c_dev->base + reg);
+}
+
+/*
+ * i2c_writel and i2c_readl will offset the register if necessary to talk
+ * to the I2C block inside the DVC block
+ */
+static unsigned long tegra_i2c_reg_addr(struct tegra_i2c_dev *i2c_dev,
+ unsigned long reg)
+{
+ if (i2c_dev->is_dvc)
+ reg += (reg >= I2C_TX_FIFO) ? 0x10 : 0x40;
+ return reg;
+}
+
+static void i2c_writel(struct tegra_i2c_dev *i2c_dev, u32 val,
+ unsigned long reg)
+{
+ writel(val, i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
+
+ /* Read back register to make sure that register writes completed */
+ if (reg != I2C_TX_FIFO)
+ readl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
+}
+
+static u32 i2c_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
+{
+ return readl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
+}
+
+static void i2c_writesl(struct tegra_i2c_dev *i2c_dev, void *data,
+ unsigned long reg, int len)
+{
+ writesl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
+}
+
+static void i2c_readsl(struct tegra_i2c_dev *i2c_dev, void *data,
+ unsigned long reg, int len)
+{
+ readsl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
+}
+
+static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev)
+{
+ uint64_t start = get_time_ns();
+ u32 val = i2c_readl(i2c_dev, I2C_FIFO_CONTROL);
+ val |= I2C_FIFO_CONTROL_TX_FLUSH | I2C_FIFO_CONTROL_RX_FLUSH;
+ i2c_writel(i2c_dev, val, I2C_FIFO_CONTROL);
+
+ while (i2c_readl(i2c_dev, I2C_FIFO_CONTROL) &
+ (I2C_FIFO_CONTROL_TX_FLUSH | I2C_FIFO_CONTROL_RX_FLUSH)) {
+ if (is_timeout(start, SECOND)) {
+ dev_warn(i2c_dev->dev, "timeout waiting for fifo flush\n");
+ return -ETIMEDOUT;
+ }
+ mdelay(1);
+ }
+ return 0;
+}
+
+static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
+{
+ u32 val;
+ int rx_fifo_avail;
+ u8 *buf = i2c_dev->msg_buf;
+ size_t buf_remaining = i2c_dev->msg_buf_remaining;
+ int words_to_transfer;
+
+ val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
+ rx_fifo_avail = (val & I2C_FIFO_STATUS_RX_MASK) >>
+ I2C_FIFO_STATUS_RX_SHIFT;
+
+ /* Rounds down to not include partial word at the end of buf */
+ words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
+ if (words_to_transfer > rx_fifo_avail)
+ words_to_transfer = rx_fifo_avail;
+
+ i2c_readsl(i2c_dev, buf, I2C_RX_FIFO, words_to_transfer);
+
+ buf += words_to_transfer * BYTES_PER_FIFO_WORD;
+ buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
+ rx_fifo_avail -= words_to_transfer;
+
+ /*
+ * If there is a partial word at the end of buf, handle it manually to
+ * prevent overwriting past the end of buf
+ */
+ if (rx_fifo_avail > 0 && buf_remaining > 0) {
+ BUG_ON(buf_remaining > 3);
+ val = i2c_readl(i2c_dev, I2C_RX_FIFO);
+ memcpy(buf, &val, buf_remaining);
+ buf_remaining = 0;
+ rx_fifo_avail--;
+ }
+
+ BUG_ON(rx_fifo_avail > 0 && buf_remaining > 0);
+ i2c_dev->msg_buf_remaining = buf_remaining;
+ i2c_dev->msg_buf = buf;
+ return 0;
+}
+
+static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev)
+{
+ u32 val;
+ int tx_fifo_avail;
+ u8 *buf = i2c_dev->msg_buf;
+ size_t buf_remaining = i2c_dev->msg_buf_remaining;
+ int words_to_transfer;
+
+ val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
+ tx_fifo_avail = (val & I2C_FIFO_STATUS_TX_MASK) >>
+ I2C_FIFO_STATUS_TX_SHIFT;
+
+ /* Rounds down to not include partial word at the end of buf */
+ words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
+
+ /* It's very common to have < 4 bytes, so optimize that case. */
+ if (words_to_transfer) {
+ if (words_to_transfer > tx_fifo_avail)
+ words_to_transfer = tx_fifo_avail;
+
+ /*
+ * Update state before writing to FIFO. If this casues us
+ * to finish writing all bytes (AKA buf_remaining goes to 0) we
+ * have a potential for an interrupt (PACKET_XFER_COMPLETE is
+ * not maskable). We need to make sure that the isr sees
+ * buf_remaining as 0 and doesn't call us back re-entrantly.
+ */
+ buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
+ tx_fifo_avail -= words_to_transfer;
+ i2c_dev->msg_buf_remaining = buf_remaining;
+ i2c_dev->msg_buf = buf +
+ words_to_transfer * BYTES_PER_FIFO_WORD;
+ barrier();
+
+ i2c_writesl(i2c_dev, buf, I2C_TX_FIFO, words_to_transfer);
+
+ buf += words_to_transfer * BYTES_PER_FIFO_WORD;
+ }
+
+ /*
+ * If there is a partial word at the end of buf, handle it manually to
+ * prevent reading past the end of buf, which could cross a page
+ * boundary and fault.
+ */
+ if (tx_fifo_avail > 0 && buf_remaining > 0) {
+ BUG_ON(buf_remaining > 3);
+ memcpy(&val, buf, buf_remaining);
+
+ /* Again update before writing to FIFO to make sure isr sees. */
+ i2c_dev->msg_buf_remaining = 0;
+ i2c_dev->msg_buf = NULL;
+ barrier();
+
+ i2c_writel(i2c_dev, val, I2C_TX_FIFO);
+ }
+
+ return 0;
+}
+
+/*
+ * One of the Tegra I2C blocks is inside the DVC (Digital Voltage Controller)
+ * block. This block is identical to the rest of the I2C blocks, except that
+ * it only supports master mode, it has registers moved around, and it needs
+ * some extra init to get it into I2C mode. The register moves are handled
+ * by i2c_readl and i2c_writel
+ */
+static void tegra_dvc_init(struct tegra_i2c_dev *i2c_dev)
+{
+ u32 val = 0;
+ val = dvc_readl(i2c_dev, DVC_CTRL_REG3);
+ val |= DVC_CTRL_REG3_SW_PROG;
+ val |= DVC_CTRL_REG3_I2C_DONE_INTR_EN;
+ dvc_writel(i2c_dev, val, DVC_CTRL_REG3);
+
+ val = dvc_readl(i2c_dev, DVC_CTRL_REG1);
+ val |= DVC_CTRL_REG1_INTR_EN;
+ dvc_writel(i2c_dev, val, DVC_CTRL_REG1);
+}
+
+static inline int tegra_i2c_clock_enable(struct tegra_i2c_dev *i2c_dev)
+{
+ int ret;
+ if (!i2c_dev->hw->has_single_clk_source) {
+ ret = clk_enable(i2c_dev->fast_clk);
+ if (ret < 0) {
+ dev_err(i2c_dev->dev,
+ "Enabling fast clk failed, err %d\n", ret);
+ return ret;
+ }
+ }
+ ret = clk_enable(i2c_dev->div_clk);
+ if (ret < 0) {
+ dev_err(i2c_dev->dev,
+ "Enabling div clk failed, err %d\n", ret);
+ clk_disable(i2c_dev->fast_clk);
+ }
+ return ret;
+}
+
+static inline void tegra_i2c_clock_disable(struct tegra_i2c_dev *i2c_dev)
+{
+ clk_disable(i2c_dev->div_clk);
+ if (!i2c_dev->hw->has_single_clk_source)
+ clk_disable(i2c_dev->fast_clk);
+}
+
+static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
+{
+ u32 val;
+ int err = 0;
+ int clk_multiplier = I2C_CLK_MULTIPLIER_STD_FAST_MODE;
+ u32 clk_divisor;
+
+ err = tegra_i2c_clock_enable(i2c_dev);
+ if (err < 0) {
+ dev_err(i2c_dev->dev, "Clock enable failed %d\n", err);
+ return err;
+ }
+
+ reset_control_assert(i2c_dev->rst);
+ udelay(2);
+ reset_control_deassert(i2c_dev->rst);
+
+ if (i2c_dev->is_dvc)
+ tegra_dvc_init(i2c_dev);
+
+ val = I2C_CNFG_NEW_MASTER_FSM | I2C_CNFG_PACKET_MODE_EN |
+ (0x2 << I2C_CNFG_DEBOUNCE_CNT_SHIFT);
+ i2c_writel(i2c_dev, val, I2C_CNFG);
+ i2c_writel(i2c_dev, 0, I2C_INT_MASK);
+
+ clk_multiplier *= (i2c_dev->hw->clk_divisor_std_fast_mode + 1);
+ clk_set_rate(i2c_dev->div_clk, i2c_dev->bus_clk_rate * clk_multiplier);
+
+ /* Make sure clock divisor programmed correctly */
+ clk_divisor = i2c_dev->hw->clk_divisor_hs_mode;
+ clk_divisor |= i2c_dev->hw->clk_divisor_std_fast_mode <<
+ I2C_CLK_DIVISOR_STD_FAST_MODE_SHIFT;
+ i2c_writel(i2c_dev, clk_divisor, I2C_CLK_DIVISOR);
+
+ if (!i2c_dev->is_dvc) {
+ u32 sl_cfg = i2c_readl(i2c_dev, I2C_SL_CNFG);
+ sl_cfg |= I2C_SL_CNFG_NACK | I2C_SL_CNFG_NEWSL;
+ i2c_writel(i2c_dev, sl_cfg, I2C_SL_CNFG);
+ i2c_writel(i2c_dev, 0xfc, I2C_SL_ADDR1);
+ i2c_writel(i2c_dev, 0x00, I2C_SL_ADDR2);
+ }
+
+ val = 7 << I2C_FIFO_CONTROL_TX_TRIG_SHIFT |
+ 0 << I2C_FIFO_CONTROL_RX_TRIG_SHIFT;
+ i2c_writel(i2c_dev, val, I2C_FIFO_CONTROL);
+
+ if (tegra_i2c_flush_fifos(i2c_dev))
+ err = -ETIMEDOUT;
+
+ tegra_i2c_clock_disable(i2c_dev);
+
+ return err;
+}
+
+static int tegra_i2c_wait_completion(struct tegra_i2c_dev *i2c_dev)
+{
+ u32 status;
+ const u32 status_err = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
+ uint64_t start = get_time_ns();
+
+ while (!is_timeout(start, SECOND)) {
+
+ status = i2c_readl(i2c_dev, I2C_INT_STATUS);
+
+ if (unlikely(status & status_err)) {
+ if (status & I2C_INT_NO_ACK)
+ i2c_dev->msg_err |= I2C_ERR_NO_ACK;
+ if (status & I2C_INT_ARBITRATION_LOST)
+ i2c_dev->msg_err |= I2C_ERR_ARBITRATION_LOST;
+ goto err;
+ }
+
+ if (i2c_dev->msg_read && (status & I2C_INT_RX_FIFO_DATA_REQ)) {
+ if (i2c_dev->msg_buf_remaining)
+ tegra_i2c_empty_rx_fifo(i2c_dev);
+ else
+ BUG();
+ }
+
+ if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
+ if (i2c_dev->msg_buf_remaining)
+ tegra_i2c_fill_tx_fifo(i2c_dev);
+ }
+
+ i2c_writel(i2c_dev, status, I2C_INT_STATUS);
+ if (i2c_dev->is_dvc)
+ dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR,
+ DVC_STATUS);
+
+ if (status & I2C_INT_PACKET_XFER_COMPLETE) {
+ BUG_ON(i2c_dev->msg_buf_remaining);
+ return 0;
+ }
+ }
+ return -ETIMEDOUT;
+
+err:
+ i2c_writel(i2c_dev, status, I2C_INT_STATUS);
+ if (i2c_dev->is_dvc)
+ dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
+
+ return 0;
+}
+
+static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
+ struct i2c_msg *msg, enum msg_end_type end_state)
+{
+ u32 packet_header;
+ int ret;
+
+ tegra_i2c_flush_fifos(i2c_dev);
+
+ if (msg->len == 0)
+ return -EINVAL;
+
+ i2c_dev->msg_buf = msg->buf;
+ i2c_dev->msg_buf_remaining = msg->len;
+ i2c_dev->msg_err = I2C_ERR_NONE;
+ i2c_dev->msg_read = (msg->flags & I2C_M_RD);
+
+ packet_header = (0 << PACKET_HEADER0_HEADER_SIZE_SHIFT) |
+ PACKET_HEADER0_PROTOCOL_I2C |
+ (i2c_dev->adapter.nr << PACKET_HEADER0_CONT_ID_SHIFT) |
+ (1 << PACKET_HEADER0_PACKET_ID_SHIFT);
+ i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
+
+ packet_header = msg->len - 1;
+ i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
+
+ packet_header = I2C_HEADER_IE_ENABLE;
+ if (end_state == MSG_END_CONTINUE)
+ packet_header |= I2C_HEADER_CONTINUE_XFER;
+ else if (end_state == MSG_END_REPEAT_START)
+ packet_header |= I2C_HEADER_REPEAT_START;
+ if (msg->flags & I2C_M_TEN) {
+ packet_header |= msg->addr;
+ packet_header |= I2C_HEADER_10BIT_ADDR;
+ } else {
+ packet_header |= msg->addr << I2C_HEADER_SLAVE_ADDR_SHIFT;
+ }
+ if (msg->flags & I2C_M_IGNORE_NAK)
+ packet_header |= I2C_HEADER_CONT_ON_NAK;
+ if (msg->flags & I2C_M_RD)
+ packet_header |= I2C_HEADER_READ;
+ i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
+
+ if (!(msg->flags & I2C_M_RD))
+ tegra_i2c_fill_tx_fifo(i2c_dev);
+
+ ret = tegra_i2c_wait_completion(i2c_dev);
+ if (ret) {
+ dev_err(i2c_dev->dev, "i2c transfer timed out\n");
+
+ tegra_i2c_init(i2c_dev);
+ return -ETIMEDOUT;
+ }
+
+ if (likely(i2c_dev->msg_err == I2C_ERR_NONE))
+ return 0;
+
+ /*
+ * NACK interrupt is generated before the I2C controller generates the
+ * STOP condition on the bus. So wait for 2 clock periods before resetting
+ * the controller so that STOP condition has been delivered properly.
+ */
+ if (i2c_dev->msg_err == I2C_ERR_NO_ACK)
+ udelay(DIV_ROUND_UP(2 * 1000000, i2c_dev->bus_clk_rate));
+
+ tegra_i2c_init(i2c_dev);
+ if (i2c_dev->msg_err == I2C_ERR_NO_ACK) {
+ if (msg->flags & I2C_M_IGNORE_NAK)
+ return 0;
+ return -EREMOTEIO;
+ }
+
+ return -EIO;
+}
+
+static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
+ int num)
+{
+ struct tegra_i2c_dev *i2c_dev = to_tegra_i2c_dev(adap);
+ int i;
+ int ret = 0;
+
+ ret = tegra_i2c_clock_enable(i2c_dev);
+ if (ret < 0) {
+ dev_err(i2c_dev->dev, "Clock enable failed %d\n", ret);
+ return ret;
+ }
+
+ for (i = 0; i < num; i++) {
+ enum msg_end_type end_type = MSG_END_STOP;
+ if (i < (num - 1))
+ end_type = MSG_END_REPEAT_START;
+ ret = tegra_i2c_xfer_msg(i2c_dev, &msgs[i], end_type);
+ if (ret)
+ break;
+ }
+ tegra_i2c_clock_disable(i2c_dev);
+ return ret ? ret : i;
+}
+
+static const struct tegra_i2c_hw_feature tegra20_i2c_hw = {
+ .has_continue_xfer_support = false,
+ .has_per_pkt_xfer_complete_irq = false,
+ .has_single_clk_source = false,
+ .clk_divisor_hs_mode = 3,
+ .clk_divisor_std_fast_mode = 0,
+};
+
+static const struct tegra_i2c_hw_feature tegra30_i2c_hw = {
+ .has_continue_xfer_support = true,
+ .has_per_pkt_xfer_complete_irq = false,
+ .has_single_clk_source = false,
+ .clk_divisor_hs_mode = 3,
+ .clk_divisor_std_fast_mode = 0,
+};
+
+static const struct tegra_i2c_hw_feature tegra114_i2c_hw = {
+ .has_continue_xfer_support = true,
+ .has_per_pkt_xfer_complete_irq = true,
+ .has_single_clk_source = true,
+ .clk_divisor_hs_mode = 1,
+ .clk_divisor_std_fast_mode = 0x19,
+};
+
+static int tegra_i2c_probe(struct device_d *dev)
+{
+ struct tegra_i2c_dev *i2c_dev;
+ struct clk *div_clk, *fast_clk;
+ void __iomem *base;
+ int ret = 0;
+
+ base = dev_request_mem_region(dev, 0);
+ if (!base) {
+ dev_err(dev, "could not get iomem region\n");
+ return -ENODEV;
+ }
+
+ div_clk = clk_get(dev, "div-clk");
+ if (IS_ERR(div_clk)) {
+ dev_err(dev, "missing controller clock");
+ return PTR_ERR(div_clk);
+ }
+
+ i2c_dev = xzalloc(sizeof(*i2c_dev));
+
+ i2c_dev->base = base;
+ i2c_dev->div_clk = div_clk;
+ i2c_dev->dev = dev;
+
+ i2c_dev->rst = reset_control_get(dev, "i2c");
+ if (IS_ERR(i2c_dev->rst)) {
+ dev_err(dev, "missing controller reset");
+ return PTR_ERR(i2c_dev->rst);
+ }
+
+ ret = of_property_read_u32(dev->device_node, "clock-frequency",
+ &i2c_dev->bus_clk_rate);
+ if (ret)
+ i2c_dev->bus_clk_rate = 100000; /* default clock rate */
+
+ i2c_dev->hw = &tegra20_i2c_hw;
+ dev_get_drvdata(dev, (unsigned long *)&i2c_dev->hw);
+ i2c_dev->is_dvc = of_device_is_compatible(dev->device_node,
+ "nvidia,tegra20-i2c-dvc");
+
+ if (!i2c_dev->hw->has_single_clk_source) {
+ fast_clk = clk_get(dev, "fast-clk");
+ if (IS_ERR(fast_clk)) {
+ dev_err(dev, "missing fast clock");
+ return PTR_ERR(fast_clk);
+ }
+ i2c_dev->fast_clk = fast_clk;
+ }
+
+ ret = tegra_i2c_init(i2c_dev);
+ if (ret) {
+ dev_err(dev, "Failed to initialize i2c controller");
+ return ret;
+ }
+
+ i2c_dev->adapter.master_xfer = tegra_i2c_xfer;
+ i2c_dev->adapter.dev.parent = dev;
+ i2c_dev->adapter.nr = dev->id;
+ i2c_dev->adapter.dev.device_node = dev->device_node;
+
+ ret = i2c_add_numbered_adapter(&i2c_dev->adapter);
+ if (ret) {
+ dev_err(dev, "Failed to add I2C adapter\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static __maybe_unused struct of_device_id tegra_i2c_compatible[] = {
+ {
+ .compatible = "nvidia,tegra114-i2c",
+ .data = (unsigned long)&tegra114_i2c_hw,
+ }, {
+ .compatible = "nvidia,tegra30-i2c",
+ .data = (unsigned long)&tegra30_i2c_hw,
+ }, {
+ .compatible = "nvidia,tegra20-i2c",
+ .data = (unsigned long)&tegra20_i2c_hw,
+ }, {
+ .compatible = "nvidia,tegra20-i2c-dvc",
+ .data = (unsigned long)&tegra20_i2c_hw,
+ }, {
+ /* sentinel */
+ }
+};
+
+static struct driver_d tegra_i2c_driver = {
+ .name = "tegra-i2c",
+ .probe = tegra_i2c_probe,
+ .of_compatible = DRV_OF_COMPAT(tegra_i2c_compatible),
+};
+device_platform_driver(tegra_i2c_driver);
--
1.9.0
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