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i2c: rcar: improve bus busy detection
I2C doesn't define a timeout for bus busy, so an arbitrary value like LOOP_TIMEOUT is not a good idea. Let's use the timeout value in struct adapter which is meant for such cases and is user-configurable (via IOCTL). To reduce the load, wait 10us instead of 1us which is good enough for the slow frequencies used by I2C. Finally, use the poll_timeout helper instead of open coding it. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> Signed-off-by: Wolfram Sang <wsa@kernel.org>
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1 changed files with 10 additions and 9 deletions
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@ -19,6 +19,7 @@
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#include <linux/err.h>
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#include <linux/interrupt.h>
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#include <linux/io.h>
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#include <linux/iopoll.h>
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#include <linux/i2c.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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@ -221,18 +222,18 @@ static void rcar_i2c_init(struct rcar_i2c_priv *priv)
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static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv)
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{
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int i;
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int ret;
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u32 val;
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for (i = 0; i < LOOP_TIMEOUT; i++) {
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/* make sure that bus is not busy */
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if (!(rcar_i2c_read(priv, ICMCR) & FSDA))
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return 0;
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udelay(1);
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ret = readl_poll_timeout(priv->io + ICMCR, val, !(val & FSDA), 10,
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priv->adap.timeout);
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if (ret) {
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/* Waiting did not help, try to recover */
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priv->recovery_icmcr = MDBS | OBPC | FSDA | FSCL;
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ret = i2c_recover_bus(&priv->adap);
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}
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/* Waiting did not help, try to recover */
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priv->recovery_icmcr = MDBS | OBPC | FSDA | FSCL;
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return i2c_recover_bus(&priv->adap);
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return ret;
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}
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static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv)
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