* [PATCH v2] i2c: tegra: Add i2c support
[not found] ` <AANLkTim0X=gUwYJmR+EAYjGamiJb7tgiVEjwqCEF0-L0-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
@ 2011-02-21 1:14 ` Colin Cross
[not found] ` <1298250861-27094-1-git-send-email-ccross-z5hGa2qSFaRBDgjK7y7TUQ@public.gmane.org>
0 siblings, 1 reply; 5+ messages in thread
From: Colin Cross @ 2011-02-21 1:14 UTC (permalink / raw)
To: Ben Dooks
Cc: Mark Brown, Ben Dooks, linux-i2c-u79uwXL29TY76Z2rM5mHXA,
swarren-DDmLM1+adcrQT0dZR+AlfA,
patches-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E,
linux-tegra-u79uwXL29TY76Z2rM5mHXA,
linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r, Colin Cross
Adds I2C bus driver for nVidia Tegra SoCs. Tegra includes 4 I2C
controllers, one of which is inside the Dynamic Voltage Controller
and has a slightly different register map.
Signed-off-by: Colin Cross <ccross-z5hGa2qSFaRBDgjK7y7TUQ@public.gmane.org>
---
v2: fixes comments from Ben Dooks and Stephen Warren
drivers/i2c/busses/Kconfig | 7 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-tegra.c | 700 ++++++++++++++++++++++++++++++++++++++++
include/linux/i2c-tegra.h | 25 ++
4 files changed, 733 insertions(+), 0 deletions(-)
create mode 100644 drivers/i2c/busses/i2c-tegra.c
create mode 100644 include/linux/i2c-tegra.h
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 113505a..a5f48dc 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -607,6 +607,13 @@ config I2C_STU300
This driver can also be built as a module. If so, the module
will be called i2c-stu300.
+config I2C_TEGRA
+ tristate "NVIDIA Tegra internal I2C controller"
+ depends on ARCH_TEGRA
+ help
+ If you say yes to this option, support will be included for the
+ I2C controller embedded in NVIDIA Tegra SOCs
+
config I2C_VERSATILE
tristate "ARM Versatile/Realview I2C bus support"
depends on ARCH_VERSATILE || ARCH_REALVIEW || ARCH_VEXPRESS
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 9d2d0ec..a0d4afe 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -58,6 +58,7 @@ obj-$(CONFIG_I2C_SH7760) += i2c-sh7760.o
obj-$(CONFIG_I2C_SH_MOBILE) += i2c-sh_mobile.o
obj-$(CONFIG_I2C_SIMTEC) += i2c-simtec.o
obj-$(CONFIG_I2C_STU300) += i2c-stu300.o
+obj-$(CONFIG_I2C_TEGRA) += i2c-tegra.o
obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o
obj-$(CONFIG_I2C_OCTEON) += i2c-octeon.o
obj-$(CONFIG_I2C_XILINX) += i2c-xiic.o
diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
new file mode 100644
index 0000000..3921f66
--- /dev/null
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -0,0 +1,700 @@
+/*
+ * drivers/i2c/busses/i2c-tegra.c
+ *
+ * Copyright (C) 2010 Google, Inc.
+ * Author: Colin Cross <ccross-z5hGa2qSFaRBDgjK7y7TUQ@public.gmane.org>
+ *
+ * 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 <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/i2c-tegra.h>
+
+#include <asm/unaligned.h>
+
+#include <mach/clk.h>
+
+#define TEGRA_I2C_TIMEOUT (msecs_to_jiffies(1000))
+#define BYTES_PER_FIFO_WORD 4
+
+#define I2C_CNFG 0x000
+#define I2C_CNFG_PACKET_MODE_EN (1<<10)
+#define I2C_CNFG_NEW_MASTER_FSM (1<<11)
+#define I2C_SL_CNFG 0x020
+#define I2C_SL_CNFG_NEWSL (1<<2)
+#define I2C_SL_ADDR1 0x02c
+#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 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 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_MASTER_ADDR_SHIFT 12
+#define I2C_HEADER_SLAVE_ADDR_SHIFT 1
+
+/**
+ * struct tegra_i2c_dev - per device i2c context
+ * @dev: device reference for power management
+ * @adapter: core i2c layer adapter information
+ * @clk: clock reference for i2c controller
+ * @i2c_clk: clock reference for i2c bus
+ * @iomem: memory resource for registers
+ * @base: ioremapped registers cookie
+ * @cont_id: i2c controller id, used for for packet header
+ * @irq: irq number of transfer complete interrupt
+ * @is_dvc: identifies the DVC i2c controller, has a different register layout
+ * @msg_complete: transfer completion notifier
+ * @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
+ * @is_suspended: prevents i2c controller accesses after suspend is called
+ */
+struct tegra_i2c_dev {
+ struct device *dev;
+ struct i2c_adapter adapter;
+ struct clk *clk;
+ struct clk *i2c_clk;
+ struct resource *iomem;
+ void __iomem *base;
+ int cont_id;
+ int irq;
+ int is_dvc;
+ struct completion msg_complete;
+ int msg_err;
+ u8 *msg_buf;
+ size_t msg_buf_remaining;
+ int msg_read;
+ unsigned long bus_clk_rate;
+ bool is_suspended;
+};
+
+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));
+}
+
+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 void tegra_i2c_mask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask)
+{
+ u32 int_mask = i2c_readl(i2c_dev, I2C_INT_MASK);
+ int_mask &= ~mask;
+ i2c_writel(i2c_dev, int_mask, I2C_INT_MASK);
+}
+
+static void tegra_i2c_unmask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask)
+{
+ u32 int_mask = i2c_readl(i2c_dev, I2C_INT_MASK);
+ int_mask |= mask;
+ i2c_writel(i2c_dev, int_mask, I2C_INT_MASK);
+}
+
+static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev)
+{
+ unsigned long timeout = jiffies + HZ;
+ 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 (time_after(jiffies, timeout)) {
+ dev_warn(i2c_dev->dev, "timeout waiting for fifo flush\n");
+ return -ETIMEDOUT;
+ }
+ msleep(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;
+ if (words_to_transfer > tx_fifo_avail)
+ words_to_transfer = tx_fifo_avail;
+
+ i2c_writesl(i2c_dev, buf, I2C_TX_FIFO, words_to_transfer);
+
+ buf += words_to_transfer * BYTES_PER_FIFO_WORD;
+ buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
+ tx_fifo_avail -= words_to_transfer;
+
+ /*
+ * 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);
+ i2c_writel(i2c_dev, val, I2C_TX_FIFO);
+ buf_remaining = 0;
+ tx_fifo_avail--;
+ }
+
+ BUG_ON(tx_fifo_avail > 0 && buf_remaining > 0);
+ i2c_dev->msg_buf_remaining = buf_remaining;
+ i2c_dev->msg_buf = buf;
+ 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 int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
+{
+ u32 val;
+ int err = 0;
+
+ clk_enable(i2c_dev->clk);
+
+ tegra_periph_reset_assert(i2c_dev->clk);
+ udelay(2);
+ tegra_periph_reset_deassert(i2c_dev->clk);
+
+ if (i2c_dev->is_dvc)
+ tegra_dvc_init(i2c_dev);
+
+ val = I2C_CNFG_NEW_MASTER_FSM | I2C_CNFG_PACKET_MODE_EN;
+ i2c_writel(i2c_dev, val, I2C_CNFG);
+ i2c_writel(i2c_dev, 0, I2C_INT_MASK);
+ clk_set_rate(i2c_dev->clk, i2c_dev->bus_clk_rate * 8);
+
+ 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;
+
+ clk_disable(i2c_dev->clk);
+ return err;
+}
+
+static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
+{
+ u32 status;
+ const u32 status_err = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
+ struct tegra_i2c_dev *i2c_dev = dev_id;
+
+ status = i2c_readl(i2c_dev, I2C_INT_STATUS);
+
+ if (status == 0) {
+ dev_warn(i2c_dev->dev, "interrupt with no status\n");
+ return IRQ_NONE;
+ }
+
+ 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;
+ complete(&i2c_dev->msg_complete);
+ 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);
+ else
+ tegra_i2c_mask_irq(i2c_dev, I2C_INT_TX_FIFO_DATA_REQ);
+ }
+
+ if ((status & I2C_INT_PACKET_XFER_COMPLETE) &&
+ !i2c_dev->msg_buf_remaining)
+ complete(&i2c_dev->msg_complete);
+
+ 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 IRQ_HANDLED;
+err:
+ /* An error occured, mask all interrupts */
+ tegra_i2c_mask_irq(i2c_dev, I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST |
+ I2C_INT_PACKET_XFER_COMPLETE | I2C_INT_TX_FIFO_DATA_REQ |
+ I2C_INT_RX_FIFO_DATA_REQ);
+ i2c_writel(i2c_dev, status, I2C_INT_STATUS);
+ return IRQ_HANDLED;
+}
+
+static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
+ struct i2c_msg *msg, int stop)
+{
+ u32 packet_header;
+ u32 int_mask;
+ int ret;
+
+ tegra_i2c_flush_fifos(i2c_dev);
+ i2c_writel(i2c_dev, 0xFF, I2C_INT_STATUS);
+
+ 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);
+ INIT_COMPLETION(i2c_dev->msg_complete);
+
+ packet_header = (0 << PACKET_HEADER0_HEADER_SIZE_SHIFT) |
+ PACKET_HEADER0_PROTOCOL_I2C |
+ (i2c_dev->cont_id << 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 = msg->addr << I2C_HEADER_SLAVE_ADDR_SHIFT;
+ packet_header |= I2C_HEADER_IE_ENABLE;
+ if (msg->flags & I2C_M_TEN)
+ packet_header |= I2C_HEADER_10BIT_ADDR;
+ if (msg->flags & I2C_M_IGNORE_NAK)
+ packet_header |= I2C_HEADER_CONT_ON_NAK;
+ if (msg->flags & I2C_M_NOSTART)
+ packet_header |= I2C_HEADER_REPEAT_START;
+ 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);
+
+ int_mask = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
+ if (msg->flags & I2C_M_RD)
+ int_mask |= I2C_INT_RX_FIFO_DATA_REQ;
+ else if (i2c_dev->msg_buf_remaining)
+ int_mask |= I2C_INT_TX_FIFO_DATA_REQ;
+ tegra_i2c_unmask_irq(i2c_dev, int_mask);
+ dev_dbg(i2c_dev->dev, "unmasked irq: %02x\n",
+ i2c_readl(i2c_dev, I2C_INT_MASK));
+
+ ret = wait_for_completion_timeout(&i2c_dev->msg_complete, TEGRA_I2C_TIMEOUT);
+ tegra_i2c_mask_irq(i2c_dev, int_mask);
+
+ if (WARN_ON(ret == 0)) {
+ dev_err(i2c_dev->dev, "i2c transfer timed out\n");
+
+ tegra_i2c_init(i2c_dev);
+ return -ETIMEDOUT;
+ }
+
+ dev_dbg(i2c_dev->dev, "transfer complete: %d %d %d\n",
+ ret, completion_done(&i2c_dev->msg_complete), i2c_dev->msg_err);
+
+ if (likely(i2c_dev->msg_err == I2C_ERR_NONE))
+ return 0;
+
+ 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 = i2c_get_adapdata(adap);
+ int i;
+ int ret = 0;
+
+ if (i2c_dev->is_suspended)
+ return -EBUSY;
+
+ clk_enable(i2c_dev->clk);
+ for (i = 0; i < num; i++) {
+ int stop = (i == (num - 1)) ? 1 : 0;
+ ret = tegra_i2c_xfer_msg(i2c_dev, &msgs[i], stop);
+ if (ret)
+ break;
+ }
+ clk_disable(i2c_dev->clk);
+ return ret ?: i;
+}
+
+static u32 tegra_i2c_func(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C;
+}
+
+static const struct i2c_algorithm tegra_i2c_algo = {
+ .master_xfer = tegra_i2c_xfer,
+ .functionality = tegra_i2c_func,
+};
+
+static int tegra_i2c_probe(struct platform_device *pdev)
+{
+ struct tegra_i2c_dev *i2c_dev;
+ struct tegra_i2c_platform_data *pdata = pdev->dev.platform_data;
+ struct resource *res;
+ struct resource *iomem;
+ struct clk *clk;
+ struct clk *i2c_clk;
+ void *base;
+ int irq;
+ int ret = 0;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "no mem resource\n");
+ return -EINVAL;
+ }
+ iomem = request_mem_region(res->start, resource_size(res), pdev->name);
+ if (!iomem) {
+ dev_err(&pdev->dev, "I2C region already claimed\n");
+ return -EBUSY;
+ }
+
+ base = ioremap(iomem->start, resource_size(iomem));
+ if (!base) {
+ dev_err(&pdev->dev, "Cannot ioremap I2C region\n");
+ return -ENOMEM;
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "no irq resource\n");
+ ret = -EINVAL;
+ goto err_iounmap;
+ }
+ irq = res->start;
+
+ clk = clk_get(&pdev->dev, NULL);
+ if (IS_ERR(clk)) {
+ dev_err(&pdev->dev, "missing controller clock");
+ ret = PTR_ERR(clk);
+ goto err_release_region;
+ }
+
+ i2c_clk = clk_get(&pdev->dev, "i2c");
+ if (IS_ERR(i2c_clk)) {
+ dev_err(&pdev->dev, "missing bus clock");
+ ret = PTR_ERR(i2c_clk);
+ goto err_clk_put;
+ }
+
+ i2c_dev = kzalloc(sizeof(struct tegra_i2c_dev), GFP_KERNEL);
+ if (!i2c_dev) {
+ ret = -ENOMEM;
+ goto err_i2c_clk_put;
+ }
+
+ i2c_dev->base = base;
+ i2c_dev->clk = clk;
+ i2c_dev->i2c_clk = i2c_clk;
+ i2c_dev->iomem = iomem;
+ i2c_dev->adapter.algo = &tegra_i2c_algo;
+ i2c_dev->irq = irq;
+ i2c_dev->cont_id = pdev->id;
+ i2c_dev->dev = &pdev->dev;
+ i2c_dev->bus_clk_rate = pdata ? pdata->bus_clk_rate : 100000;
+
+ if (pdev->id == 3)
+ i2c_dev->is_dvc = 1;
+ init_completion(&i2c_dev->msg_complete);
+
+ platform_set_drvdata(pdev, i2c_dev);
+
+ ret = tegra_i2c_init(i2c_dev);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to initialize i2c controller");
+ goto err_free;
+ }
+
+ ret = request_irq(i2c_dev->irq, tegra_i2c_isr, 0, pdev->name, i2c_dev);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to request irq %i\n", i2c_dev->irq);
+ goto err_free;
+ }
+
+ clk_enable(i2c_dev->i2c_clk);
+
+ i2c_set_adapdata(&i2c_dev->adapter, i2c_dev);
+ i2c_dev->adapter.owner = THIS_MODULE;
+ i2c_dev->adapter.class = I2C_CLASS_HWMON;
+ strlcpy(i2c_dev->adapter.name, "Tegra I2C adapter",
+ sizeof(i2c_dev->adapter.name));
+ i2c_dev->adapter.algo = &tegra_i2c_algo;
+ i2c_dev->adapter.dev.parent = &pdev->dev;
+ i2c_dev->adapter.nr = pdev->id;
+
+ ret = i2c_add_numbered_adapter(&i2c_dev->adapter);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to add I2C adapter\n");
+ goto err_free_irq;
+ }
+
+ return 0;
+err_free_irq:
+ free_irq(i2c_dev->irq, i2c_dev);
+err_free:
+ kfree(i2c_dev);
+err_i2c_clk_put:
+ clk_put(i2c_clk);
+err_clk_put:
+ clk_put(clk);
+err_release_region:
+ release_mem_region(iomem->start, resource_size(iomem));
+err_iounmap:
+ iounmap(base);
+ return ret;
+}
+
+static int tegra_i2c_remove(struct platform_device *pdev)
+{
+ struct tegra_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
+ i2c_del_adapter(&i2c_dev->adapter);
+ free_irq(i2c_dev->irq, i2c_dev);
+ clk_put(i2c_dev->i2c_clk);
+ clk_put(i2c_dev->clk);
+ release_mem_region(i2c_dev->iomem->start,
+ resource_size(i2c_dev->iomem));
+ iounmap(i2c_dev->base);
+ kfree(i2c_dev);
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int tegra_i2c_suspend(struct platform_device *pdev, pm_message_t state)
+{
+ struct tegra_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
+
+ i2c_lock_adapter(&i2c_dev->adapter);
+ i2c_dev->is_suspended = true;
+ i2c_unlock_adapter(&i2c_dev->adapter);
+
+ return 0;
+}
+
+static int tegra_i2c_resume(struct platform_device *pdev)
+{
+ struct tegra_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
+ int ret;
+
+ i2c_lock_adapter(&i2c_dev->adapter);
+
+ ret = tegra_i2c_init(i2c_dev);
+
+ if (ret) {
+ i2c_unlock_adapter(&i2c_dev->adapter);
+ return ret;
+ }
+
+ i2c_dev->is_suspended = false;
+
+ i2c_unlock_adapter(&i2c_dev->adapter);
+
+ return 0;
+}
+#endif
+
+static struct platform_driver tegra_i2c_driver = {
+ .probe = tegra_i2c_probe,
+ .remove = tegra_i2c_remove,
+#ifdef CONFIG_PM
+ .suspend = tegra_i2c_suspend,
+ .resume = tegra_i2c_resume,
+#endif
+ .driver = {
+ .name = "tegra-i2c",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init tegra_i2c_init_driver(void)
+{
+ return platform_driver_register(&tegra_i2c_driver);
+}
+
+static void __exit tegra_i2c_exit_driver(void)
+{
+ platform_driver_unregister(&tegra_i2c_driver);
+}
+
+subsys_initcall(tegra_i2c_init_driver);
+module_exit(tegra_i2c_exit_driver);
+
+MODULE_DESCRIPTION("nVidia Tegra2 I2C Bus Controller driver");
+MODULE_AUTHOR("Colin Cross");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/i2c-tegra.h b/include/linux/i2c-tegra.h
new file mode 100644
index 0000000..9c85da4
--- /dev/null
+++ b/include/linux/i2c-tegra.h
@@ -0,0 +1,25 @@
+/*
+ * drivers/i2c/busses/i2c-tegra.c
+ *
+ * Copyright (C) 2010 Google, Inc.
+ * Author: Colin Cross <ccross-z5hGa2qSFaRBDgjK7y7TUQ@public.gmane.org>
+ *
+ * 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.
+ *
+ */
+
+#ifndef _LINUX_I2C_TEGRA_H
+#define _LINUX_I2C_TEGRA_H
+
+struct tegra_i2c_platform_data {
+ unsigned long bus_clk_rate;
+};
+
+#endif /* _LINUX_I2C_TEGRA_H */
--
1.7.3.1
^ permalink raw reply related [flat|nested] 5+ messages in thread