tegra: Add i2c support

+/* i2c_writel and i2c_readl will offset the register if necessary to talk
+ * to the I2C block inside the DVC block
+ */

Quoted 4 lines · Colin Cross

+/* i2c_writel and i2c_readl will offset the register if necessary to talk
+ * to the I2C block inside the DVC block
+ */

Minor coding-style comment. Documentation/CodingStyle says the preferred format for multi-line comments is to do:

/*
?* i2c_writel and i2c_readl ...
?* to the I2C block ...
?*/

From: Colin Cross <[email protected]>

CC linux-i2c at vger.kernel.org

Signed-off-by Colin Cross <[email protected]>

---

?drivers/i2c/busses/Kconfig ? ? | ? ?7 +
?drivers/i2c/busses/Makefile ? ?| ? ?1 +
?drivers/i2c/busses/i2c-tegra.c | ?665 ++++++++++++++++++++++++++++++++++++++++
?include/linux/i2c-tegra.h ? ? ?| ? 25 ++

?4 files changed, 698 insertions(+), 0 deletions(-) ?create mode 100644 drivers/i2c/busses/i2c-tegra.c ?create mode 100644 include/linux/i2c-tegra.h

drivers/i2c/busses/Kconfig +0 -0

index bceafbf..a4dbfdb 100644
@@ -582,6 +582,13 @@ config I2C_STU300

? ? ? ? ?This driver can also be built as a module. If so, the module ? ? ? ? ?will be called i2c-stu300.

drivers/i2c/busses/Kconfig +7 -0

+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

drivers/i2c/busses/Makefile +0 -0

index 936880b..0d401c4 100644
@@ -56,6 +56,7 @@ 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

drivers/i2c/busses/i2c-tegra.c new file +454 -0

new file mode 100644
index 0000000..ee8a7aa
@@ -0,0 +1,665 @@
+/*
+ * drivers/i2c/busses/i2c-tegra.c
+ *
+ * Copyright (C) 2010 Google, Inc.
+ * Author: Colin Cross <[email protected]>
+ *
+ * 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/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 {
+ ? ? ? 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;
+ ? ? ? int msg_transfer_complete;
+ ? ? ? 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 void i2c_writel(struct tegra_i2c_dev *i2c_dev, u32 val, unsigned long reg)
+{
+ ? ? ? if (i2c_dev->is_dvc)
+ ? ? ? ? ? ? ? reg += (reg >= I2C_TX_FIFO) ? 0x10 : 0x40;
+ ? ? ? writel(val, i2c_dev->base + reg);
+}
+
+static u32 i2c_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
+{
+ ? ? ? if (i2c_dev->is_dvc)
+ ? ? ? ? ? ? ? reg += (reg >= I2C_TX_FIFO) ? 0x10 : 0x40;
+ ? ? ? return readl(i2c_dev->base + reg);
+}
+
+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 void tegra_i2c_set_clk(struct tegra_i2c_dev *i2c_dev, unsigned int freq)
+{
+ ? ? ? clk_set_rate(i2c_dev->clk, freq * 8);
+}
+
+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;
+ ? ? ? int word;
+ ? ? ? 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;
+
+ ? ? ? words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
+ ? ? ? if (words_to_transfer > rx_fifo_avail)
+ ? ? ? ? ? ? ? words_to_transfer = rx_fifo_avail;
+
+ ? ? ? for (word = 0; word < words_to_transfer; word++) {
+ ? ? ? ? ? ? ? val = i2c_readl(i2c_dev, I2C_RX_FIFO);
+ ? ? ? ? ? ? ? put_unaligned_le32(val, buf);
+ ? ? ? ? ? ? ? buf += BYTES_PER_FIFO_WORD;
+ ? ? ? ? ? ? ? buf_remaining -= BYTES_PER_FIFO_WORD;
+ ? ? ? ? ? ? ? rx_fifo_avail--;
+ ? ? ? }
+
+ ? ? ? if (rx_fifo_avail > 0 && buf_remaining > 0) {
+ ? ? ? ? ? ? ? int bytes_to_transfer = buf_remaining;
+ ? ? ? ? ? ? ? int byte;
+ ? ? ? ? ? ? ? BUG_ON(bytes_to_transfer > 3);
+ ? ? ? ? ? ? ? val = i2c_readl(i2c_dev, I2C_RX_FIFO);
+ ? ? ? ? ? ? ? for (byte = 0; byte < bytes_to_transfer; byte++) {
+ ? ? ? ? ? ? ? ? ? ? ? *buf++ = val & 0xFF;
+ ? ? ? ? ? ? ? ? ? ? ? val >>= 8;
+ ? ? ? ? ? ? ? }
+ ? ? ? ? ? ? ? buf_remaining -= bytes_to_transfer;
+ ? ? ? ? ? ? ? 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;
+ ? ? ? int word;
+ ? ? ? 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;
+
+ ? ? ? words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
+ ? ? ? if (words_to_transfer > tx_fifo_avail)
+ ? ? ? ? ? ? ? words_to_transfer = tx_fifo_avail;
+
+ ? ? ? for (word = 0; word < words_to_transfer; word++) {
+ ? ? ? ? ? ? ? val = get_unaligned_le32(buf);
+ ? ? ? ? ? ? ? i2c_writel(i2c_dev, val, I2C_TX_FIFO);
+ ? ? ? ? ? ? ? buf += BYTES_PER_FIFO_WORD;
+ ? ? ? ? ? ? ? buf_remaining -= BYTES_PER_FIFO_WORD;
+ ? ? ? ? ? ? ? tx_fifo_avail--;
+ ? ? ? }
+
+ ? ? ? if (tx_fifo_avail > 0 && buf_remaining > 0) {
+ ? ? ? ? ? ? ? int bytes_to_transfer = buf_remaining;
+ ? ? ? ? ? ? ? int byte;
+ ? ? ? ? ? ? ? BUG_ON(bytes_to_transfer > 3);
+ ? ? ? ? ? ? ? val = 0;
+ ? ? ? ? ? ? ? for (byte = 0; byte < bytes_to_transfer; byte++)
+ ? ? ? ? ? ? ? ? ? ? ? val |= (*buf++) << (byte * 8);
+ ? ? ? ? ? ? ? i2c_writel(i2c_dev, val, I2C_TX_FIFO);
+ ? ? ? ? ? ? ? buf_remaining -= bytes_to_transfer;
+ ? ? ? ? ? ? ? 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;
+
+ ? ? ? tegra_periph_reset_assert(i2c_dev->clk);
+ ? ? ? msleep(1);
+ ? ? ? tegra_periph_reset_deassert(i2c_dev->clk);
+ ? ? ? msleep(1);
+
+ ? ? ? clk_enable(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);
+ ? ? ? tegra_i2c_set_clk(i2c_dev, i2c_dev->bus_clk_rate);
+
+ ? ? ? 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 0;
+}
+
+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, "irq status 0 %08x\n",
+ ? ? ? ? ? ? ? ? ? ? ? i2c_readl(i2c_dev, I2C_PACKET_TRANSFER_STATUS));
+ ? ? ? ? ? ? ? return IRQ_HANDLED;
+ ? ? ? }
+
+ ? ? ? 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_transfer_complete = 1;
+
+ ? ? ? if (i2c_dev->msg_transfer_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_transfer_complete = 0;
+ ? ? ? 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);
+ ? ? ? pr_debug("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;
+ ? ? ? }
+
+ ? ? ? pr_debug("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;

drivers/i2c/busses/i2c-tegra.c new file +201 -0

+}
+
+static u32 tegra_i2c_func(struct i2c_adapter *adap)
+{
+ ? ? ? /* FIXME: For now keep it simple and don't support protocol mangling
+ ? ? ? ? ?features */
+ ? ? ? 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 -ENODEV;
+ ? ? ? }
+ ? ? ? 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, "Can't 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 = -ENODEV;
+ ? ? ? ? ? ? ? goto err_iounmap;
+ ? ? ? }
+ ? ? ? irq = res->start;
+
+ ? ? ? clk = clk_get(&pdev->dev, NULL);
+ ? ? ? if (!clk) {
+ ? ? ? ? ? ? ? ret = -ENOMEM;
+ ? ? ? ? ? ? ? goto err_release_region;
+ ? ? ? }
+
+ ? ? ? i2c_clk = clk_get(&pdev->dev, "i2c");
+ ? ? ? if (!i2c_clk) {
+ ? ? ? ? ? ? ? ret = -ENOMEM;
+ ? ? ? ? ? ? ? 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)
+ ? ? ? ? ? ? ? goto err_free;
+
+ ? ? ? ret = request_irq(i2c_dev->irq, tegra_i2c_isr, IRQF_DISABLED,
+ ? ? ? ? ? ? ? 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);
+}
+module_init(tegra_i2c_init_driver);
+
+static void __exit tegra_i2c_exit_driver(void)
+{
+ ? ? ? platform_driver_unregister(&tegra_i2c_driver);
+}
+module_exit(tegra_i2c_exit_driver);

include/linux/i2c-tegra.h new file +25 -1

new file mode 100644
index 0000000..9c85da4
@@ -0,0 +1,25 @@
+/*
+ * drivers/i2c/busses/i2c-tegra.c
+ *
+ * Copyright (C) 2010 Google, Inc.
+ * Author: Colin Cross <[email protected]>
+ *
+ * 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 */
--

1.7.1

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Hi Colin,

Quoted 15 lines · Colin Cross

(quoted diff) +15 -0

+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)

Quoted 4 lines

+ ? ? ? ? ? ? ? ? ? ? ? break;
+ ? ? ? }
+ ? ? ? clk_disable(i2c_dev->clk);
+ ? ? ? return i;

In case of error the i2c_transfer should return the error code, so the return statement should be
? ? ? return ret ?: i;

From: Colin Cross <[email protected]>

CC linux-i2c at vger.kernel.org

Signed-off-by Colin Cross <[email protected]>

---
 drivers/i2c/busses/Kconfig     |    7 +
 drivers/i2c/busses/Makefile    |    1 +
 drivers/i2c/busses/i2c-tegra.c |  665 ++++++++++++++++++++++++++++++++++++++++
 include/linux/i2c-tegra.h      |   25 ++

 4 files changed, 698 insertions(+), 0 deletions(-)
 create mode 100644 drivers/i2c/busses/i2c-tegra.c
 create mode 100644 include/linux/i2c-tegra.h

drivers/i2c/busses/i2c-tegra.c new file +6 -0

+
+static void __exit tegra_i2c_exit_driver(void)
+{
+	platform_driver_unregister(&tegra_i2c_driver);
+}
+module_exit(tegra_i2c_exit_driver);

include/linux/i2c-tegra.h new file +25 -0

new file mode 100644
index 0000000..9c85da4
@@ -0,0 +1,25 @@
+/*
+ * drivers/i2c/busses/i2c-tegra.c
+ *
+ * Copyright (C) 2010 Google, Inc.
+ * Author: Colin Cross <[email protected]>
+ *
+ * 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 */

Hi Colin,
Two more comments.

Quoted 11 lines · Colin Cross

From: Colin Cross <[email protected]>

CC linux-i2c at vger.kernel.org

Signed-off-by Colin Cross <[email protected]>

---

?drivers/i2c/busses/Kconfig ? ? | ? ?7 +
?drivers/i2c/busses/Makefile ? ?| ? ?1 +
?drivers/i2c/busses/i2c-tegra.c | ?665

++++++++++++++++++++++++++++++++++++++++
?include/linux/i2c-tegra.h ? ? ?| ? 25 ++

This should probably go to arch/arm/mach-tegra/include/mach/ to minimize the pollution in include/linux

Quoted 4 lines

?4 files changed, 698 insertions(+), 0 deletions(-) ?create mode 100644 drivers/i2c/busses/i2c-tegra.c ?create mode 100644 include/linux/i2c-tegra.h

[ snip ]

drivers/i2c/busses/i2c-tegra.c line 659

Quoted 6 lines

drivers/i2c/busses/i2c-tegra.c new file +6 -0

+
+static int __init tegra_i2c_init_driver(void)
+{
+ ? ? ? return platform_driver_register(&tegra_i2c_driver);
+}
+module_init(tegra_i2c_init_driver);

subsys_initcall would be better here.

Quoted 16 lines · Mike Rapoport

Hi Colin,
Two more comments.

Quoted 11 lines · Colin Cross

From: Colin Cross <[email protected]>

CC linux-i2c at vger.kernel.org

Signed-off-by Colin Cross <[email protected]>

---

?drivers/i2c/busses/Kconfig ? ? | ? ?7 +
?drivers/i2c/busses/Makefile ? ?| ? ?1 +
?drivers/i2c/busses/i2c-tegra.c | ?665

++++++++++++++++++++++++++++++++++++++++
?include/linux/i2c-tegra.h ? ? ?| ? 25 ++

Quoted 2 lines

This should probably go to arch/arm/mach-tegra/include/mach/ to minimize the pollution in include/linux

The existing standard seems to be to use include/linux

Quoted 7 lines

Quoted 4 lines

?4 files changed, 698 insertions(+), 0 deletions(-) ?create mode 100644 drivers/i2c/busses/i2c-tegra.c ?create mode 100644 include/linux/i2c-tegra.h

[ snip ]

Quoted 8 lines

drivers/i2c/busses/i2c-tegra.c line 659

Quoted 6 lines

drivers/i2c/busses/i2c-tegra.c new file +6 -0

+
+static int __init tegra_i2c_init_driver(void)
+{
+ ? ? ? return platform_driver_register(&tegra_i2c_driver);
+}
+module_init(tegra_i2c_init_driver);

subsys_initcall would be better here.

This can be compiled as a module, subsys_initcall would break that.