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authorLinus Torvalds <torvalds@linux-foundation.org>2014-12-20 13:52:52 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-12-20 13:52:52 -0800
commita4e1328a9d20ccf4a9e5a19fce172e6deb2a33e2 (patch)
tree6dca79d197408609608a1d3ac732dbbc94587f6f /drivers/i2c/busses/i2c-mv64xxx.c
parentcdce6ac277a4a1aa5316cd0cdf30fff927433917 (diff)
parentfe07adec730d271c91f4160f96a0f24fe7553c63 (diff)
downloadlinux-stericsson-a4e1328a9d20ccf4a9e5a19fce172e6deb2a33e2.tar.gz
Merge branch 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull more i2c updates from Wolfram Sang: "Included are two bugfixes needing some bigger refactoring (sh_mobile: deferred probe with DMA, mv64xxx: fix offload support) and one deprecated driver removal I thought would go in via ppc but I misunderstood. It has a proper ack from BenH" * 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: i2c: sh_mobile: fix uninitialized var when debug is enabled macintosh: therm_pm72: delete deprecated driver i2c: sh_mobile: I2C_SH_MOBILE should depend on HAS_DMA i2c: sh_mobile: rework deferred probing i2c: sh_mobile: refactor DMA setup i2c: mv64xxx: rework offload support to fix several problems i2c: mv64xxx: use BIT() macro for register value definitions
Diffstat (limited to 'drivers/i2c/busses/i2c-mv64xxx.c')
-rw-r--r--drivers/i2c/busses/i2c-mv64xxx.c328
1 files changed, 197 insertions, 131 deletions
diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
index 373f6d4e4080..30059c1df2a3 100644
--- a/drivers/i2c/busses/i2c-mv64xxx.c
+++ b/drivers/i2c/busses/i2c-mv64xxx.c
@@ -30,12 +30,12 @@
#define MV64XXX_I2C_BAUD_DIV_N(val) (val & 0x7)
#define MV64XXX_I2C_BAUD_DIV_M(val) ((val & 0xf) << 3)
-#define MV64XXX_I2C_REG_CONTROL_ACK 0x00000004
-#define MV64XXX_I2C_REG_CONTROL_IFLG 0x00000008
-#define MV64XXX_I2C_REG_CONTROL_STOP 0x00000010
-#define MV64XXX_I2C_REG_CONTROL_START 0x00000020
-#define MV64XXX_I2C_REG_CONTROL_TWSIEN 0x00000040
-#define MV64XXX_I2C_REG_CONTROL_INTEN 0x00000080
+#define MV64XXX_I2C_REG_CONTROL_ACK BIT(2)
+#define MV64XXX_I2C_REG_CONTROL_IFLG BIT(3)
+#define MV64XXX_I2C_REG_CONTROL_STOP BIT(4)
+#define MV64XXX_I2C_REG_CONTROL_START BIT(5)
+#define MV64XXX_I2C_REG_CONTROL_TWSIEN BIT(6)
+#define MV64XXX_I2C_REG_CONTROL_INTEN BIT(7)
/* Ctlr status values */
#define MV64XXX_I2C_STATUS_BUS_ERR 0x00
@@ -68,19 +68,17 @@
#define MV64XXX_I2C_REG_BRIDGE_TIMING 0xe0
/* Bridge Control values */
-#define MV64XXX_I2C_BRIDGE_CONTROL_WR 0x00000001
-#define MV64XXX_I2C_BRIDGE_CONTROL_RD 0x00000002
+#define MV64XXX_I2C_BRIDGE_CONTROL_WR BIT(0)
+#define MV64XXX_I2C_BRIDGE_CONTROL_RD BIT(1)
#define MV64XXX_I2C_BRIDGE_CONTROL_ADDR_SHIFT 2
-#define MV64XXX_I2C_BRIDGE_CONTROL_ADDR_EXT 0x00001000
+#define MV64XXX_I2C_BRIDGE_CONTROL_ADDR_EXT BIT(12)
#define MV64XXX_I2C_BRIDGE_CONTROL_TX_SIZE_SHIFT 13
#define MV64XXX_I2C_BRIDGE_CONTROL_RX_SIZE_SHIFT 16
-#define MV64XXX_I2C_BRIDGE_CONTROL_ENABLE 0x00080000
+#define MV64XXX_I2C_BRIDGE_CONTROL_ENABLE BIT(19)
+#define MV64XXX_I2C_BRIDGE_CONTROL_REPEATED_START BIT(20)
/* Bridge Status values */
-#define MV64XXX_I2C_BRIDGE_STATUS_ERROR 0x00000001
-#define MV64XXX_I2C_STATUS_OFFLOAD_ERROR 0xf0000001
-#define MV64XXX_I2C_STATUS_OFFLOAD_OK 0xf0000000
-
+#define MV64XXX_I2C_BRIDGE_STATUS_ERROR BIT(0)
/* Driver states */
enum {
@@ -99,14 +97,12 @@ enum {
MV64XXX_I2C_ACTION_INVALID,
MV64XXX_I2C_ACTION_CONTINUE,
MV64XXX_I2C_ACTION_SEND_RESTART,
- MV64XXX_I2C_ACTION_OFFLOAD_RESTART,
MV64XXX_I2C_ACTION_SEND_ADDR_1,
MV64XXX_I2C_ACTION_SEND_ADDR_2,
MV64XXX_I2C_ACTION_SEND_DATA,
MV64XXX_I2C_ACTION_RCV_DATA,
MV64XXX_I2C_ACTION_RCV_DATA_STOP,
MV64XXX_I2C_ACTION_SEND_STOP,
- MV64XXX_I2C_ACTION_OFFLOAD_SEND_STOP,
};
struct mv64xxx_i2c_regs {
@@ -193,75 +189,6 @@ mv64xxx_i2c_prepare_for_io(struct mv64xxx_i2c_data *drv_data,
}
}
-static int mv64xxx_i2c_offload_msg(struct mv64xxx_i2c_data *drv_data)
-{
- unsigned long data_reg_hi = 0;
- unsigned long data_reg_lo = 0;
- unsigned long ctrl_reg;
- struct i2c_msg *msg = drv_data->msgs;
-
- if (!drv_data->offload_enabled)
- return -EOPNOTSUPP;
-
- /* Only regular transactions can be offloaded */
- if ((msg->flags & ~(I2C_M_TEN | I2C_M_RD)) != 0)
- return -EINVAL;
-
- /* Only 1-8 byte transfers can be offloaded */
- if (msg->len < 1 || msg->len > 8)
- return -EINVAL;
-
- /* Build transaction */
- ctrl_reg = MV64XXX_I2C_BRIDGE_CONTROL_ENABLE |
- (msg->addr << MV64XXX_I2C_BRIDGE_CONTROL_ADDR_SHIFT);
-
- if ((msg->flags & I2C_M_TEN) != 0)
- ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_ADDR_EXT;
-
- if ((msg->flags & I2C_M_RD) == 0) {
- u8 local_buf[8] = { 0 };
-
- memcpy(local_buf, msg->buf, msg->len);
- data_reg_lo = cpu_to_le32(*((u32 *)local_buf));
- data_reg_hi = cpu_to_le32(*((u32 *)(local_buf+4)));
-
- ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_WR |
- (msg->len - 1) << MV64XXX_I2C_BRIDGE_CONTROL_TX_SIZE_SHIFT;
-
- writel(data_reg_lo,
- drv_data->reg_base + MV64XXX_I2C_REG_TX_DATA_LO);
- writel(data_reg_hi,
- drv_data->reg_base + MV64XXX_I2C_REG_TX_DATA_HI);
-
- } else {
- ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_RD |
- (msg->len - 1) << MV64XXX_I2C_BRIDGE_CONTROL_RX_SIZE_SHIFT;
- }
-
- /* Execute transaction */
- writel(ctrl_reg, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL);
-
- return 0;
-}
-
-static void
-mv64xxx_i2c_update_offload_data(struct mv64xxx_i2c_data *drv_data)
-{
- struct i2c_msg *msg = drv_data->msg;
-
- if (msg->flags & I2C_M_RD) {
- u32 data_reg_lo = readl(drv_data->reg_base +
- MV64XXX_I2C_REG_RX_DATA_LO);
- u32 data_reg_hi = readl(drv_data->reg_base +
- MV64XXX_I2C_REG_RX_DATA_HI);
- u8 local_buf[8] = { 0 };
-
- *((u32 *)local_buf) = le32_to_cpu(data_reg_lo);
- *((u32 *)(local_buf+4)) = le32_to_cpu(data_reg_hi);
- memcpy(msg->buf, local_buf, msg->len);
- }
-
-}
/*
*****************************************************************************
*
@@ -389,16 +316,6 @@ mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status)
drv_data->rc = -ENXIO;
break;
- case MV64XXX_I2C_STATUS_OFFLOAD_OK:
- if (drv_data->send_stop || drv_data->aborting) {
- drv_data->action = MV64XXX_I2C_ACTION_OFFLOAD_SEND_STOP;
- drv_data->state = MV64XXX_I2C_STATE_IDLE;
- } else {
- drv_data->action = MV64XXX_I2C_ACTION_OFFLOAD_RESTART;
- drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_RESTART;
- }
- break;
-
default:
dev_err(&drv_data->adapter.dev,
"mv64xxx_i2c_fsm: Ctlr Error -- state: 0x%x, "
@@ -419,25 +336,15 @@ static void mv64xxx_i2c_send_start(struct mv64xxx_i2c_data *drv_data)
drv_data->aborting = 0;
drv_data->rc = 0;
- /* Can we offload this msg ? */
- if (mv64xxx_i2c_offload_msg(drv_data) < 0) {
- /* No, switch to standard path */
- mv64xxx_i2c_prepare_for_io(drv_data, drv_data->msgs);
- writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_START,
- drv_data->reg_base + drv_data->reg_offsets.control);
- }
+ mv64xxx_i2c_prepare_for_io(drv_data, drv_data->msgs);
+ writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_START,
+ drv_data->reg_base + drv_data->reg_offsets.control);
}
static void
mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data)
{
switch(drv_data->action) {
- case MV64XXX_I2C_ACTION_OFFLOAD_RESTART:
- mv64xxx_i2c_update_offload_data(drv_data);
- writel(0, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL);
- writel(0, drv_data->reg_base +
- MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE);
- /* FALLTHRU */
case MV64XXX_I2C_ACTION_SEND_RESTART:
/* We should only get here if we have further messages */
BUG_ON(drv_data->num_msgs == 0);
@@ -518,16 +425,71 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data)
drv_data->block = 0;
wake_up(&drv_data->waitq);
break;
+ }
+}
- case MV64XXX_I2C_ACTION_OFFLOAD_SEND_STOP:
- mv64xxx_i2c_update_offload_data(drv_data);
- writel(0, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL);
- writel(0, drv_data->reg_base +
- MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE);
- drv_data->block = 0;
- wake_up(&drv_data->waitq);
- break;
+static void
+mv64xxx_i2c_read_offload_rx_data(struct mv64xxx_i2c_data *drv_data,
+ struct i2c_msg *msg)
+{
+ u32 buf[2];
+
+ buf[0] = readl(drv_data->reg_base + MV64XXX_I2C_REG_RX_DATA_LO);
+ buf[1] = readl(drv_data->reg_base + MV64XXX_I2C_REG_RX_DATA_HI);
+
+ memcpy(msg->buf, buf, msg->len);
+}
+
+static int
+mv64xxx_i2c_intr_offload(struct mv64xxx_i2c_data *drv_data)
+{
+ u32 cause, status;
+
+ cause = readl(drv_data->reg_base +
+ MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE);
+ if (!cause)
+ return IRQ_NONE;
+
+ status = readl(drv_data->reg_base +
+ MV64XXX_I2C_REG_BRIDGE_STATUS);
+
+ if (status & MV64XXX_I2C_BRIDGE_STATUS_ERROR) {
+ drv_data->rc = -EIO;
+ goto out;
+ }
+
+ drv_data->rc = 0;
+
+ /*
+ * Transaction is a one message read transaction, read data
+ * for this message.
+ */
+ if (drv_data->num_msgs == 1 && drv_data->msgs[0].flags & I2C_M_RD) {
+ mv64xxx_i2c_read_offload_rx_data(drv_data, drv_data->msgs);
+ drv_data->msgs++;
+ drv_data->num_msgs--;
+ }
+ /*
+ * Transaction is a two messages write/read transaction, read
+ * data for the second (read) message.
+ */
+ else if (drv_data->num_msgs == 2 &&
+ !(drv_data->msgs[0].flags & I2C_M_RD) &&
+ drv_data->msgs[1].flags & I2C_M_RD) {
+ mv64xxx_i2c_read_offload_rx_data(drv_data, drv_data->msgs + 1);
+ drv_data->msgs += 2;
+ drv_data->num_msgs -= 2;
}
+
+out:
+ writel(0, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL);
+ writel(0, drv_data->reg_base +
+ MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE);
+ drv_data->block = 0;
+
+ wake_up(&drv_data->waitq);
+
+ return IRQ_HANDLED;
}
static irqreturn_t
@@ -540,20 +502,9 @@ mv64xxx_i2c_intr(int irq, void *dev_id)
spin_lock_irqsave(&drv_data->lock, flags);
- if (drv_data->offload_enabled) {
- while (readl(drv_data->reg_base +
- MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE)) {
- int reg_status = readl(drv_data->reg_base +
- MV64XXX_I2C_REG_BRIDGE_STATUS);
- if (reg_status & MV64XXX_I2C_BRIDGE_STATUS_ERROR)
- status = MV64XXX_I2C_STATUS_OFFLOAD_ERROR;
- else
- status = MV64XXX_I2C_STATUS_OFFLOAD_OK;
- mv64xxx_i2c_fsm(drv_data, status);
- mv64xxx_i2c_do_action(drv_data);
- rc = IRQ_HANDLED;
- }
- }
+ if (drv_data->offload_enabled)
+ rc = mv64xxx_i2c_intr_offload(drv_data);
+
while (readl(drv_data->reg_base + drv_data->reg_offsets.control) &
MV64XXX_I2C_REG_CONTROL_IFLG) {
status = readl(drv_data->reg_base + drv_data->reg_offsets.status);
@@ -635,6 +586,117 @@ mv64xxx_i2c_execute_msg(struct mv64xxx_i2c_data *drv_data, struct i2c_msg *msg,
return drv_data->rc;
}
+static void
+mv64xxx_i2c_prepare_tx(struct mv64xxx_i2c_data *drv_data)
+{
+ struct i2c_msg *msg = drv_data->msgs;
+ u32 buf[2];
+
+ memcpy(buf, msg->buf, msg->len);
+
+ writel(buf[0], drv_data->reg_base + MV64XXX_I2C_REG_TX_DATA_LO);
+ writel(buf[1], drv_data->reg_base + MV64XXX_I2C_REG_TX_DATA_HI);
+}
+
+static int
+mv64xxx_i2c_offload_xfer(struct mv64xxx_i2c_data *drv_data)
+{
+ struct i2c_msg *msgs = drv_data->msgs;
+ int num = drv_data->num_msgs;
+ unsigned long ctrl_reg;
+ unsigned long flags;
+
+ spin_lock_irqsave(&drv_data->lock, flags);
+
+ /* Build transaction */
+ ctrl_reg = MV64XXX_I2C_BRIDGE_CONTROL_ENABLE |
+ (msgs[0].addr << MV64XXX_I2C_BRIDGE_CONTROL_ADDR_SHIFT);
+
+ if (msgs[0].flags & I2C_M_TEN)
+ ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_ADDR_EXT;
+
+ /* Single write message transaction */
+ if (num == 1 && !(msgs[0].flags & I2C_M_RD)) {
+ size_t len = msgs[0].len - 1;
+
+ ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_WR |
+ (len << MV64XXX_I2C_BRIDGE_CONTROL_TX_SIZE_SHIFT);
+ mv64xxx_i2c_prepare_tx(drv_data);
+ }
+ /* Single read message transaction */
+ else if (num == 1 && msgs[0].flags & I2C_M_RD) {
+ size_t len = msgs[0].len - 1;
+
+ ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_RD |
+ (len << MV64XXX_I2C_BRIDGE_CONTROL_RX_SIZE_SHIFT);
+ }
+ /*
+ * Transaction with one write and one read message. This is
+ * guaranteed by the mv64xx_i2c_can_offload() checks.
+ */
+ else if (num == 2) {
+ size_t lentx = msgs[0].len - 1;
+ size_t lenrx = msgs[1].len - 1;
+
+ ctrl_reg |=
+ MV64XXX_I2C_BRIDGE_CONTROL_RD |
+ MV64XXX_I2C_BRIDGE_CONTROL_WR |
+ (lentx << MV64XXX_I2C_BRIDGE_CONTROL_TX_SIZE_SHIFT) |
+ (lenrx << MV64XXX_I2C_BRIDGE_CONTROL_RX_SIZE_SHIFT) |
+ MV64XXX_I2C_BRIDGE_CONTROL_REPEATED_START;
+ mv64xxx_i2c_prepare_tx(drv_data);
+ }
+
+ /* Execute transaction */
+ drv_data->block = 1;
+ writel(ctrl_reg, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL);
+ spin_unlock_irqrestore(&drv_data->lock, flags);
+
+ mv64xxx_i2c_wait_for_completion(drv_data);
+
+ return drv_data->rc;
+}
+
+static bool
+mv64xxx_i2c_valid_offload_sz(struct i2c_msg *msg)
+{
+ return msg->len <= 8 && msg->len >= 1;
+}
+
+static bool
+mv64xxx_i2c_can_offload(struct mv64xxx_i2c_data *drv_data)
+{
+ struct i2c_msg *msgs = drv_data->msgs;
+ int num = drv_data->num_msgs;
+
+ return false;
+
+ if (!drv_data->offload_enabled)
+ return false;
+
+ /*
+ * We can offload a transaction consisting of a single
+ * message, as long as the message has a length between 1 and
+ * 8 bytes.
+ */
+ if (num == 1 && mv64xxx_i2c_valid_offload_sz(msgs))
+ return true;
+
+ /*
+ * We can offload a transaction consisting of two messages, if
+ * the first is a write and a second is a read, and both have
+ * a length between 1 and 8 bytes.
+ */
+ if (num == 2 &&
+ mv64xxx_i2c_valid_offload_sz(msgs) &&
+ mv64xxx_i2c_valid_offload_sz(msgs + 1) &&
+ !(msgs[0].flags & I2C_M_RD) &&
+ msgs[1].flags & I2C_M_RD)
+ return true;
+
+ return false;
+}
+
/*
*****************************************************************************
*
@@ -658,7 +720,11 @@ mv64xxx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
drv_data->msgs = msgs;
drv_data->num_msgs = num;
- rc = mv64xxx_i2c_execute_msg(drv_data, &msgs[0], num == 1);
+ if (mv64xxx_i2c_can_offload(drv_data))
+ rc = mv64xxx_i2c_offload_xfer(drv_data);
+ else
+ rc = mv64xxx_i2c_execute_msg(drv_data, &msgs[0], num == 1);
+
if (rc < 0)
ret = rc;