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Message-Id: <20180717114837.21839-2-alexandre.belloni@bootlin.com>
Date: Tue, 17 Jul 2018 13:48:33 +0200
From: Alexandre Belloni <alexandre.belloni@...tlin.com>
To: Wolfram Sang <wsa@...-dreams.de>,
Jarkko Nikula <jarkko.nikula@...ux.intel.com>,
James Hogan <jhogan@...nel.org>
Cc: Paul Burton <paul.burton@...s.com>,
Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
Mika Westerberg <mika.westerberg@...ux.intel.com>,
linux-i2c@...r.kernel.org, devicetree@...r.kernel.org,
linux-kernel@...r.kernel.org, linux-mips@...ux-mips.org,
Thomas Petazzoni <thomas.petazzoni@...tlin.com>,
Allan Nielsen <allan.nielsen@...rosemi.com>,
Alexandre Belloni <alexandre.belloni@...tlin.com>
Subject: [PATCH 1/5] i2c: designware: factorize setting SDA hold time
Factorize setting the SDA hold time in a new function
i2c_dw_set_sda_hold_time() that is used for both master and slave mode.
This conveniently pulls the fix for the spurious warning from commit
7a20e707aae2 ("i2c: designware: suppress unneeded SDA hold time warnings")
in slave mode.
Signed-off-by: Alexandre Belloni <alexandre.belloni@...tlin.com>
---
drivers/i2c/busses/i2c-designware-common.c | 27 ++++++++++++++++++++++
drivers/i2c/busses/i2c-designware-core.h | 1 +
drivers/i2c/busses/i2c-designware-master.c | 22 +-----------------
drivers/i2c/busses/i2c-designware-slave.c | 22 +-----------------
4 files changed, 30 insertions(+), 42 deletions(-)
diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busses/i2c-designware-common.c
index 48914dfc8ce8..9afc3e075b33 100644
--- a/drivers/i2c/busses/i2c-designware-common.c
+++ b/drivers/i2c/busses/i2c-designware-common.c
@@ -293,5 +293,32 @@ u32 i2c_dw_read_comp_param(struct dw_i2c_dev *dev)
}
EXPORT_SYMBOL_GPL(i2c_dw_read_comp_param);
+void i2c_dw_set_sda_hold_time(struct dw_i2c_dev *dev)
+{
+ u32 reg;
+
+ /* Configure SDA Hold Time if required. */
+ reg = dw_readl(dev, DW_IC_COMP_VERSION);
+ if (reg >= DW_IC_SDA_HOLD_MIN_VERS) {
+ if (!dev->sda_hold_time) {
+ /* Keep previous hold time setting if no one set it. */
+ dev->sda_hold_time = dw_readl(dev, DW_IC_SDA_HOLD);
+ }
+ /*
+ * Workaround for avoiding TX arbitration lost in case I2C
+ * slave pulls SDA down "too quickly" after falling egde of
+ * SCL by enabling non-zero SDA RX hold. Specification says it
+ * extends incoming SDA low to high transition while SCL is
+ * high but it apprears to help also above issue.
+ */
+ if (!(dev->sda_hold_time & DW_IC_SDA_HOLD_RX_MASK))
+ dev->sda_hold_time |= 1 << DW_IC_SDA_HOLD_RX_SHIFT;
+ dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD);
+ } else if (dev->sda_hold_time) {
+ dev_warn(dev->dev,
+ "Hardware too old to adjust SDA hold time.\n");
+ }
+}
+
MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter core");
MODULE_LICENSE("GPL");
diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index d690e648bc01..bc43fb9ac1cf 100644
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -306,6 +306,7 @@ int i2c_dw_handle_tx_abort(struct dw_i2c_dev *dev);
u32 i2c_dw_func(struct i2c_adapter *adap);
void i2c_dw_disable(struct dw_i2c_dev *dev);
void i2c_dw_disable_int(struct dw_i2c_dev *dev);
+void i2c_dw_set_sda_hold_time(struct dw_i2c_dev *dev);
static inline void __i2c_dw_enable(struct dw_i2c_dev *dev)
{
diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
index 27436a937492..826329f8e30b 100644
--- a/drivers/i2c/busses/i2c-designware-master.c
+++ b/drivers/i2c/busses/i2c-designware-master.c
@@ -146,27 +146,7 @@ static int i2c_dw_init_master(struct dw_i2c_dev *dev)
}
}
- /* Configure SDA Hold Time if required */
- reg = dw_readl(dev, DW_IC_COMP_VERSION);
- if (reg >= DW_IC_SDA_HOLD_MIN_VERS) {
- if (!dev->sda_hold_time) {
- /* Keep previous hold time setting if no one set it */
- dev->sda_hold_time = dw_readl(dev, DW_IC_SDA_HOLD);
- }
- /*
- * Workaround for avoiding TX arbitration lost in case I2C
- * slave pulls SDA down "too quickly" after falling egde of
- * SCL by enabling non-zero SDA RX hold. Specification says it
- * extends incoming SDA low to high transition while SCL is
- * high but it apprears to help also above issue.
- */
- if (!(dev->sda_hold_time & DW_IC_SDA_HOLD_RX_MASK))
- dev->sda_hold_time |= 1 << DW_IC_SDA_HOLD_RX_SHIFT;
- dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD);
- } else if (dev->sda_hold_time) {
- dev_warn(dev->dev,
- "Hardware too old to adjust SDA hold time.\n");
- }
+ i2c_dw_set_sda_hold_time(dev);
i2c_dw_configure_fifo_master(dev);
i2c_dw_release_lock(dev);
diff --git a/drivers/i2c/busses/i2c-designware-slave.c b/drivers/i2c/busses/i2c-designware-slave.c
index 8ce2cd368477..150e5edb064c 100644
--- a/drivers/i2c/busses/i2c-designware-slave.c
+++ b/drivers/i2c/busses/i2c-designware-slave.c
@@ -77,27 +77,7 @@ static int i2c_dw_init_slave(struct dw_i2c_dev *dev)
/* Disable the adapter. */
__i2c_dw_disable(dev);
- /* Configure SDA Hold Time if required. */
- reg = dw_readl(dev, DW_IC_COMP_VERSION);
- if (reg >= DW_IC_SDA_HOLD_MIN_VERS) {
- if (!dev->sda_hold_time) {
- /* Keep previous hold time setting if no one set it. */
- dev->sda_hold_time = dw_readl(dev, DW_IC_SDA_HOLD);
- }
- /*
- * Workaround for avoiding TX arbitration lost in case I2C
- * slave pulls SDA down "too quickly" after falling egde of
- * SCL by enabling non-zero SDA RX hold. Specification says it
- * extends incoming SDA low to high transition while SCL is
- * high but it apprears to help also above issue.
- */
- if (!(dev->sda_hold_time & DW_IC_SDA_HOLD_RX_MASK))
- dev->sda_hold_time |= 1 << DW_IC_SDA_HOLD_RX_SHIFT;
- dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD);
- } else {
- dev_warn(dev->dev,
- "Hardware too old to adjust SDA hold time.\n");
- }
+ i2c_dw_set_sda_hold_time(dev);
i2c_dw_configure_fifo_slave(dev);
i2c_dw_release_lock(dev);
--
2.18.0
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