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