Re: [PATCH v11 7/7] drm/lsdc: add drm driver for loongson display controller

[Rob Herring <robh@kernel.org>]

On Wed, Mar 23, 2022 at 12:12:43PM +0800, Sui Jingfeng wrote:
> 
> On 2022/3/23 04:49, Rob Herring wrote:
> > > +/*
> > > + * mainly for dc in ls7a1000 which have builtin gpio emulated i2c
> > > + *
> > > + * @index : output channel index, 0 for DVO0, 1 for DVO1
> > > + */
> > > +struct lsdc_i2c *lsdc_create_i2c_chan(struct device *dev, void *base, unsigned int index)
> > > +{
> > > +	char compat[32] = {0};
> > > +	unsigned int udelay = 5;
> > > +	unsigned int timeout = 2200;
> > > +	int nr = -1;
> > > +	struct i2c_adapter *adapter;
> > > +	struct lsdc_i2c *li2c;
> > > +	struct device_node *i2c_np;
> > > +	int ret;
> > > +
> > > +	li2c = devm_kzalloc(dev, sizeof(*li2c), GFP_KERNEL);
> > > +	if (!li2c)
> > > +		return ERR_PTR(-ENOMEM);
> > > +
> > > +	li2c->index = index;
> > > +	li2c->dev = dev;
> > > +
> > > +	if (index == 0) {
> > > +		li2c->sda = 0x01;
> > > +		li2c->scl = 0x02;
> > > +	} else if (index == 1) {
> > > +		li2c->sda = 0x04;
> > > +		li2c->scl = 0x08;
> > Just require this to be in DT rather than having some default.
> > 
> By design,  I am try very hard to let the code NOT fully  DT dependent. DT is nice , easy to learn and use.
> But kernel side developer plan to follow UEFI + ACPI Specification on LS3A5000 + LS7A1000 platform. See [1]
> There will no DT support then, provide a convention support  make the driver more flexible. I want the
> driver works with minimal requirement. The driver just works on simple boards by put the following dc device
> node in arch/mips/dts/loongson/loongson64g_4core_ls7a.dts,

Pick DT or ACPI for the platform, not both. We don't need to have both 
in the kernel to support.

Rob