diff options
Diffstat (limited to 'target/linux/layerscape/patches-5.4/808-i2c-0014-i2c-mux-pca954x-support-property-idle-state.patch')
| -rw-r--r-- | target/linux/layerscape/patches-5.4/808-i2c-0014-i2c-mux-pca954x-support-property-idle-state.patch | 165 |
1 files changed, 0 insertions, 165 deletions
diff --git a/target/linux/layerscape/patches-5.4/808-i2c-0014-i2c-mux-pca954x-support-property-idle-state.patch b/target/linux/layerscape/patches-5.4/808-i2c-0014-i2c-mux-pca954x-support-property-idle-state.patch deleted file mode 100644 index 4263717f43..0000000000 --- a/target/linux/layerscape/patches-5.4/808-i2c-0014-i2c-mux-pca954x-support-property-idle-state.patch +++ /dev/null @@ -1,165 +0,0 @@ -From 5b51284db77e6383ff438b1dd21ee83bb6eaa895 Mon Sep 17 00:00:00 2001 -From: Biwen Li <biwen.li@nxp.com> -Date: Tue, 22 Oct 2019 12:11:51 +0800 -Subject: [PATCH] i2c: mux: pca954x: support property idle-state - -This supports property idle-state,if present, -overrides i2c-mux-idle-disconnect. - -My use cases: - - Use the property idle-state to fix - an errata on LS2085ARDB and LS2088ARDB. - - Errata id: E-00013(board LS2085ARDB and - LS2088ARDB revision on Rev.B, Rev.C and Rev.D). - - About E-00013: - - Description: I2C1 and I2C3 buses - are missing pull-up. - - Impact: When the PCA954x device is tri-stated, the I2C bus - will float. This makes the I2C bus and its associated - downstream devices inaccessible. - - Hardware fix: Populate resistors R189 and R190 for I2C1 - and resistors R228 and R229 for I2C3. - - Software fix: Remove the tri-state option from the PCA954x - driver(PCA954x always on enable status, specify a - channel zero in dts to fix the errata E-00013). - -Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> -Signed-off-by: Biwen Li <biwen.li@nxp.com> ---- - drivers/i2c/muxes/i2c-mux-pca954x.c | 69 ++++++++++++++++++++++++------------- - 1 file changed, 46 insertions(+), 23 deletions(-) - ---- a/drivers/i2c/muxes/i2c-mux-pca954x.c -+++ b/drivers/i2c/muxes/i2c-mux-pca954x.c -@@ -87,7 +87,7 @@ struct pca954x { - - u8 last_chan; /* last register value */ - /* MUX_IDLE_AS_IS, MUX_IDLE_DISCONNECT or >= 0 for channel */ -- s8 idle_state; -+ s32 idle_state; - - struct i2c_client *client; - -@@ -237,20 +237,23 @@ static int pca954x_reg_write(struct i2c_ - I2C_SMBUS_BYTE, &dummy); - } - -+static u8 pca954x_regval(struct pca954x *data, u8 chan) -+{ -+ /* We make switches look like muxes, not sure how to be smarter. */ -+ if (data->chip->muxtype == pca954x_ismux) -+ return chan | data->chip->enable; -+ else -+ return 1 << chan; -+} -+ - static int pca954x_select_chan(struct i2c_mux_core *muxc, u32 chan) - { - struct pca954x *data = i2c_mux_priv(muxc); - struct i2c_client *client = data->client; -- const struct chip_desc *chip = data->chip; - u8 regval; - int ret = 0; - -- /* we make switches look like muxes, not sure how to be smarter */ -- if (chip->muxtype == pca954x_ismux) -- regval = chan | chip->enable; -- else -- regval = 1 << chan; -- -+ regval = pca954x_regval(data, chan); - /* Only select the channel if its different from the last channel */ - if (data->last_chan != regval) { - ret = pca954x_reg_write(muxc->parent, client, regval); -@@ -264,7 +267,7 @@ static int pca954x_deselect_mux(struct i - { - struct pca954x *data = i2c_mux_priv(muxc); - struct i2c_client *client = data->client; -- s8 idle_state; -+ s32 idle_state; - - idle_state = READ_ONCE(data->idle_state); - if (idle_state >= 0) -@@ -410,6 +413,22 @@ static void pca954x_cleanup(struct i2c_m - i2c_mux_del_adapters(muxc); - } - -+static int pca954x_init(struct i2c_client *client, struct pca954x *data) -+{ -+ int ret; -+ if (data->idle_state >= 0) { -+ data->last_chan = pca954x_regval(data, data->idle_state); -+ } else { -+ /* Disconnect multiplexer */ -+ data->last_chan = 0; -+ } -+ ret = i2c_smbus_write_byte(client, data->last_chan); -+ if (ret < 0) -+ data->last_chan = 0; -+ -+ return ret; -+} -+ - /* - * I2C init/probing/exit functions - */ -@@ -419,7 +438,6 @@ static int pca954x_probe(struct i2c_clie - struct i2c_adapter *adap = client->adapter; - struct device *dev = &client->dev; - struct device_node *np = dev->of_node; -- bool idle_disconnect_dt; - struct gpio_desc *gpio; - struct i2c_mux_core *muxc; - struct pca954x *data; -@@ -470,23 +488,24 @@ static int pca954x_probe(struct i2c_clie - } - } - -- /* Write the mux register at addr to verify -+ data->idle_state = MUX_IDLE_AS_IS; -+ if (of_property_read_u32(np, "idle-state", &data->idle_state)) { -+ if (np && of_property_read_bool(np, "i2c-mux-idle-disconnect")) -+ data->idle_state = MUX_IDLE_DISCONNECT; -+ } -+ -+ /* -+ * Write the mux register at addr to verify - * that the mux is in fact present. This also -- * initializes the mux to disconnected state. -+ * initializes the mux to a channel -+ * or disconnected state. - */ -- if (i2c_smbus_write_byte(client, 0) < 0) { -+ ret = pca954x_init(client, data); -+ if (ret < 0) { - dev_warn(dev, "probe failed\n"); - return -ENODEV; - } - -- data->last_chan = 0; /* force the first selection */ -- data->idle_state = MUX_IDLE_AS_IS; -- -- idle_disconnect_dt = np && -- of_property_read_bool(np, "i2c-mux-idle-disconnect"); -- if (idle_disconnect_dt) -- data->idle_state = MUX_IDLE_DISCONNECT; -- - ret = pca954x_irq_setup(muxc); - if (ret) - goto fail_cleanup; -@@ -538,9 +557,13 @@ static int pca954x_resume(struct device - struct i2c_client *client = to_i2c_client(dev); - struct i2c_mux_core *muxc = i2c_get_clientdata(client); - struct pca954x *data = i2c_mux_priv(muxc); -+ int ret; - -- data->last_chan = 0; -- return i2c_smbus_write_byte(client, 0); -+ ret = pca954x_init(client, data); -+ if (ret < 0) -+ dev_err(&client->dev, "failed to verify the mux, the mux maybe not present in fact\n"); -+ -+ return ret; - } - #endif - |