[PATCH 2/4] i2c: nomadik: support Mobileye EyeQ6H I2C controller

From: Théo Lebrun
Date: Tue Oct 08 2024 - 06:30:57 EST


Add EyeQ6H support to the nmk-i2c AMBA driver. It shares the same quirk
as EyeQ5: the memory bus only supports 32-bit accesses. Avoid writeb()
and readb() by reusing the same `priv->has_32b_bus` flag.

It does NOT need to write speed-mode specific value into a register;
therefore it does not depend on the mobileye,olb DT property.

Refactoring is done using is_eyeq5 and is_eyeq6h boolean local
variables. Sort variables in reverse christmas tree to try and
introduce some logic into the ordering.

Signed-off-by: Théo Lebrun <theo.lebrun@xxxxxxxxxxx>
---
drivers/i2c/busses/i2c-nomadik.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c
index ad0f02acdb1215a1c04729f97bb14a4d93f88456..ea511d3a58073eaedb63850026e05b59427a69c6 100644
--- a/drivers/i2c/busses/i2c-nomadik.c
+++ b/drivers/i2c/busses/i2c-nomadik.c
@@ -6,10 +6,10 @@
* I2C master mode controller driver, used in Nomadik 8815
* and Ux500 platforms.
*
- * The Mobileye EyeQ5 platform is also supported; it uses
+ * The Mobileye EyeQ5 and EyeQ6H platforms are also supported; they use
* the same Ux500/DB8500 IP block with two quirks:
* - The memory bus only supports 32-bit accesses.
- * - A register must be configured for the I2C speed mode;
+ * - (only EyeQ5) A register must be configured for the I2C speed mode;
* it is located in a shared register region called OLB.
*
* Author: Srinidhi Kasagar <srinidhi.kasagar@xxxxxxxxxxxxxx>
@@ -1046,8 +1046,6 @@ static int nmk_i2c_eyeq5_probe(struct nmk_i2c_dev *priv)
struct regmap *olb;
unsigned int id;

- priv->has_32b_bus = true;
-
olb = syscon_regmap_lookup_by_phandle_args(np, "mobileye,olb", 1, &id);
if (IS_ERR(olb))
return PTR_ERR(olb);
@@ -1070,13 +1068,15 @@ static int nmk_i2c_eyeq5_probe(struct nmk_i2c_dev *priv)

static int nmk_i2c_probe(struct amba_device *adev, const struct amba_id *id)
{
- int ret = 0;
- struct nmk_i2c_dev *priv;
- struct device_node *np = adev->dev.of_node;
- struct device *dev = &adev->dev;
- struct i2c_adapter *adap;
struct i2c_vendor_data *vendor = id->data;
+ struct device_node *np = adev->dev.of_node;
+ bool is_eyeq6h = of_device_is_compatible(np, "mobileye,eyeq6h-i2c");
+ bool is_eyeq5 = of_device_is_compatible(np, "mobileye,eyeq5-i2c");
u32 max_fifo_threshold = (vendor->fifodepth / 2) - 1;
+ struct device *dev = &adev->dev;
+ struct nmk_i2c_dev *priv;
+ struct i2c_adapter *adap;
+ int ret = 0;

priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
@@ -1084,10 +1084,10 @@ static int nmk_i2c_probe(struct amba_device *adev, const struct amba_id *id)

priv->vendor = vendor;
priv->adev = adev;
- priv->has_32b_bus = false;
+ priv->has_32b_bus = is_eyeq5 || is_eyeq6h;
nmk_i2c_of_probe(np, priv);

- if (of_device_is_compatible(np, "mobileye,eyeq5-i2c")) {
+ if (is_eyeq5) {
ret = nmk_i2c_eyeq5_probe(priv);
if (ret)
return dev_err_probe(dev, ret, "failed OLB lookup\n");

--
2.46.2