134 lines
		
	
	
		
			4.3 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			134 lines
		
	
	
		
			4.3 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
| From 3c5032fe34f1af50e9e5fe58d40bf93c1717302f Mon Sep 17 00:00:00 2001
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| From: Yangbo Lu <yangbo.lu@nxp.com>
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| Date: Mon, 25 Sep 2017 12:19:53 +0800
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| Subject: [PATCH] i2c: support layerscape
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| 
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| This is a integrated patch for layerscape i2c support.
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| 
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| Signed-off-by: Zhang Ying-22455 <ying.zhang22455@nxp.com>
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| Signed-off-by: Priyanka Jain <Priyanka.Jain@freescale.com>
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| Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
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| ---
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|  drivers/i2c/busses/i2c-imx.c        | 10 ++++++++-
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|  drivers/i2c/muxes/i2c-mux-pca954x.c | 43 +++++++++++++++++++++++++++++++++++++
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|  2 files changed, 52 insertions(+), 1 deletion(-)
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| 
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| --- a/drivers/i2c/busses/i2c-imx.c
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| +++ b/drivers/i2c/busses/i2c-imx.c
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| @@ -889,6 +889,14 @@ static int i2c_imx_xfer(struct i2c_adapt
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|  
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|  	dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
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|  
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| +	/*
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| +	 * workround for ERR010027: ensure that the I2C BUS is idle
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| +	 * before switching to master mode and attempting a Start cycle
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| +	 */
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| +	result =  i2c_imx_bus_busy(i2c_imx, 0);
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| +	if (result)
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| +		goto out;
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| +
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|  	result = pm_runtime_get_sync(i2c_imx->adapter.dev.parent);
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|  	if (result < 0)
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|  		goto out;
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| @@ -1100,7 +1108,7 @@ static int i2c_imx_probe(struct platform
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|  	}
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|  
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|  	/* Request IRQ */
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| -	ret = devm_request_irq(&pdev->dev, irq, i2c_imx_isr, 0,
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| +	ret = devm_request_irq(&pdev->dev, irq, i2c_imx_isr, IRQF_SHARED,
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|  				pdev->name, i2c_imx);
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|  	if (ret) {
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|  		dev_err(&pdev->dev, "can't claim irq %d\n", irq);
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| --- a/drivers/i2c/muxes/i2c-mux-pca954x.c
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| +++ b/drivers/i2c/muxes/i2c-mux-pca954x.c
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| @@ -74,6 +74,7 @@ struct pca954x {
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|  	u8 last_chan;		/* last register value */
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|  	u8 deselect;
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|  	struct i2c_client *client;
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| +	u8 disable_mux;		/* do not disable mux if val not 0 */
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|  };
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|  
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|  /* Provide specs for the PCA954x types we know about */
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| @@ -196,6 +197,13 @@ static int pca954x_deselect_mux(struct i
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|  	if (!(data->deselect & (1 << chan)))
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|  		return 0;
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|  
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| +#ifdef CONFIG_ARCH_LAYERSCAPE
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| +	if (data->disable_mux != 0)
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| +		data->last_chan = data->chip->nchans;
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| +	else
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| +		data->last_chan = 0;
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| +	return pca954x_reg_write(muxc->parent, client, data->disable_mux);
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| +#endif
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|  	/* Deselect active channel */
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|  	data->last_chan = 0;
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|  	return pca954x_reg_write(muxc->parent, client, data->last_chan);
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| @@ -228,6 +236,28 @@ static int pca954x_probe(struct i2c_clie
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|  		return -ENOMEM;
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|  	data = i2c_mux_priv(muxc);
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|  
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| +#ifdef CONFIG_ARCH_LAYERSCAPE
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| +	/* The point here is that you must not disable a mux if there
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| +	 * are no pullups on the input or you mess up the I2C. This
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| +	 * needs to be put into the DTS really as the kernel cannot
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| +	 * know this otherwise.
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| +	 */
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| +	match = of_match_device(of_match_ptr(pca954x_of_match), &client->dev);
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| +	if (match)
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| +		data->chip = of_device_get_match_data(&client->dev);
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| +	else
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| +		data->chip = &chips[id->driver_data];
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| +
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| +	data->disable_mux = of_node &&
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| +		of_property_read_bool(of_node, "i2c-mux-never-disable") &&
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| +		data->chip->muxtype == pca954x_ismux ?
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| +		data->chip->enable : 0;
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| +	/* force the first selection */
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| +	if (data->disable_mux != 0)
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| +		data->last_chan = data->chip->nchans;
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| +	else
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| +		data->last_chan = 0;
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| +#endif
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|  	i2c_set_clientdata(client, muxc);
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|  	data->client = client;
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|  
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| @@ -240,11 +270,16 @@ static int pca954x_probe(struct i2c_clie
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|  	 * that the mux is in fact present. This also
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|  	 * initializes the mux to disconnected state.
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|  	 */
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| +#ifdef CONFIG_ARCH_LAYERSCAPE
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| +	if (i2c_smbus_write_byte(client, data->disable_mux) < 0) {
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| +#else
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|  	if (i2c_smbus_write_byte(client, 0) < 0) {
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| +#endif
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|  		dev_warn(&client->dev, "probe failed\n");
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|  		return -ENODEV;
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|  	}
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|  
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| +#ifndef CONFIG_ARCH_LAYERSCAPE
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|  	match = of_match_device(of_match_ptr(pca954x_of_match), &client->dev);
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|  	if (match)
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|  		data->chip = of_device_get_match_data(&client->dev);
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| @@ -252,6 +287,7 @@ static int pca954x_probe(struct i2c_clie
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|  		data->chip = &chips[id->driver_data];
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|  
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|  	data->last_chan = 0;		   /* force the first selection */
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| +#endif
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|  
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|  	idle_disconnect_dt = of_node &&
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|  		of_property_read_bool(of_node, "i2c-mux-idle-disconnect");
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| @@ -312,6 +348,13 @@ static int pca954x_resume(struct device
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|  	struct i2c_mux_core *muxc = i2c_get_clientdata(client);
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|  	struct pca954x *data = i2c_mux_priv(muxc);
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|  
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| +#ifdef CONFIG_ARCH_LAYERSCAPE
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| +	if (data->disable_mux != 0)
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| +		data->last_chan = data->chip->nchans;
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| +	else
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| +		data->last_chan = 0;
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| +	return i2c_smbus_write_byte(client, data->disable_mux);
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| +#endif
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|  	data->last_chan = 0;
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|  	return i2c_smbus_write_byte(client, 0);
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|  }
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