From: Chris Morgan macromorgan@hotmail.com
commit 544a8d75f3d6e60e160cd92dc56321484598a993 upstream.
Add an atomic_xfer method to the driver so that it behaves correctly when controlling a PMIC that is responsible for device shutdown.
The atomic_xfer method added is similar to the one from the i2c-rk3x driver. When running an atomic_xfer a bool flag in the driver data is set, the interrupt is not unmasked on transfer start, and the IRQ handler is manually invoked while waiting for pending transfers to complete.
Signed-off-by: Chris Morgan macromorgan@hotmail.com Acked-by: Gregory CLEMENT gregory.clement@bootlin.com Signed-off-by: Wolfram Sang wsa@kernel.org Cc: Tong Zhang ztong0001@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/i2c/busses/i2c-mv64xxx.c | 52 ++++++++++++++++++++++++++++++++++----- 1 file changed, 46 insertions(+), 6 deletions(-)
--- a/drivers/i2c/busses/i2c-mv64xxx.c +++ b/drivers/i2c/busses/i2c-mv64xxx.c @@ -150,6 +150,7 @@ struct mv64xxx_i2c_data { /* Clk div is 2 to the power n, not 2 to the power n + 1 */ bool clk_n_base_0; struct i2c_bus_recovery_info rinfo; + bool atomic; };
static struct mv64xxx_i2c_regs mv64xxx_i2c_regs_mv64xxx = { @@ -179,7 +180,10 @@ mv64xxx_i2c_prepare_for_io(struct mv64xx u32 dir = 0;
drv_data->cntl_bits = MV64XXX_I2C_REG_CONTROL_ACK | - MV64XXX_I2C_REG_CONTROL_INTEN | MV64XXX_I2C_REG_CONTROL_TWSIEN; + MV64XXX_I2C_REG_CONTROL_TWSIEN; + + if (!drv_data->atomic) + drv_data->cntl_bits |= MV64XXX_I2C_REG_CONTROL_INTEN;
if (msg->flags & I2C_M_RD) dir = 1; @@ -409,7 +413,8 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c case MV64XXX_I2C_ACTION_RCV_DATA_STOP: drv_data->msg->buf[drv_data->byte_posn++] = readl(drv_data->reg_base + drv_data->reg_offsets.data); - drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN; + if (!drv_data->atomic) + drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN; writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP, drv_data->reg_base + drv_data->reg_offsets.control); drv_data->block = 0; @@ -427,7 +432,8 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c drv_data->rc = -EIO; fallthrough; case MV64XXX_I2C_ACTION_SEND_STOP: - drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN; + if (!drv_data->atomic) + drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN; writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP, drv_data->reg_base + drv_data->reg_offsets.control); drv_data->block = 0; @@ -575,6 +581,17 @@ mv64xxx_i2c_wait_for_completion(struct m spin_unlock_irqrestore(&drv_data->lock, flags); }
+static void mv64xxx_i2c_wait_polling(struct mv64xxx_i2c_data *drv_data) +{ + ktime_t timeout = ktime_add_ms(ktime_get(), drv_data->adapter.timeout); + + while (READ_ONCE(drv_data->block) && + ktime_compare(ktime_get(), timeout) < 0) { + udelay(5); + mv64xxx_i2c_intr(0, drv_data); + } +} + static int mv64xxx_i2c_execute_msg(struct mv64xxx_i2c_data *drv_data, struct i2c_msg *msg, int is_last) @@ -590,7 +607,11 @@ mv64xxx_i2c_execute_msg(struct mv64xxx_i mv64xxx_i2c_send_start(drv_data); spin_unlock_irqrestore(&drv_data->lock, flags);
- mv64xxx_i2c_wait_for_completion(drv_data); + if (!drv_data->atomic) + mv64xxx_i2c_wait_for_completion(drv_data); + else + mv64xxx_i2c_wait_polling(drv_data); + return drv_data->rc; }
@@ -717,7 +738,7 @@ mv64xxx_i2c_functionality(struct i2c_ada }
static int -mv64xxx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) +mv64xxx_i2c_xfer_core(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) { struct mv64xxx_i2c_data *drv_data = i2c_get_adapdata(adap); int rc, ret = num; @@ -730,7 +751,7 @@ mv64xxx_i2c_xfer(struct i2c_adapter *ada drv_data->msgs = msgs; drv_data->num_msgs = num;
- if (mv64xxx_i2c_can_offload(drv_data)) + if (mv64xxx_i2c_can_offload(drv_data) && !drv_data->atomic) rc = mv64xxx_i2c_offload_xfer(drv_data); else rc = mv64xxx_i2c_execute_msg(drv_data, &msgs[0], num == 1); @@ -747,8 +768,27 @@ mv64xxx_i2c_xfer(struct i2c_adapter *ada return ret; }
+static int +mv64xxx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) +{ + struct mv64xxx_i2c_data *drv_data = i2c_get_adapdata(adap); + + drv_data->atomic = 0; + return mv64xxx_i2c_xfer_core(adap, msgs, num); +} + +static int mv64xxx_i2c_xfer_atomic(struct i2c_adapter *adap, + struct i2c_msg msgs[], int num) +{ + struct mv64xxx_i2c_data *drv_data = i2c_get_adapdata(adap); + + drv_data->atomic = 1; + return mv64xxx_i2c_xfer_core(adap, msgs, num); +} + static const struct i2c_algorithm mv64xxx_i2c_algo = { .master_xfer = mv64xxx_i2c_xfer, + .master_xfer_atomic = mv64xxx_i2c_xfer_atomic, .functionality = mv64xxx_i2c_functionality, };