clk: mediatek: reset: Support inuput argument index mode

There is a large number of mediatek infra reset bits, but we do not use
all of them. In addition, the proper input argement of reset controller
soulde be index.
Therefore, to be compatible with previous drivers and usage, we add
description variables to store the ids which can mapping to index.

To use this mode, we need to put the id in rst_idx_map to map from
index to ids. For example, if we want to input index 1 (this index
is used to set bank 1 bit 14) for svs, we need to declare the reset
controller like this:

In drivers:
static u16 rst_ofs[] = {
        0x120, 0x130, 0x140, 0x150, 0x730,
};

static u16 rst_idx_map[] = {
        0 * 32 + 0,
        1 * 32 + 14,
        ....
};

static const struct mtk_clk_rst_desc clk_rst_desc = {
        .version = MTK_RST_SET_CLR,
        .rst_bank_ofs = rst_ofs,
        .rst_bank_nr = ARRAY_SIZE(rst_ofs),
        .rst_idx_map = rst_idx_map,
        .rst_idx_map_nr = ARRAY_SIZE(rst_idx_map),
};

In dts:
svs: {
        ...
        resets = <&infra 1>;
        ...
};

Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Link: https://lore.kernel.org/r/20220523093346.28493-9-rex-bc.chen@mediatek.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

1 files changed, 20 insertions, 1 deletions

diff --git a/drivers/clk/mediatek/reset.c b/drivers/clk/mediatek/reset.c
index 11b2f74f121d..89e617ea6393 100644
--- a/drivers/clk/mediatek/reset.c
+++ b/drivers/clk/mediatek/reset.c
@@ -98,6 +98,18 @@ static const struct reset_control_ops mtk_reset_ops_set_clr = {
 	.reset = mtk_reset_set_clr,
 };
 
+static int reset_xlate(struct reset_controller_dev *rcdev,
+		       const struct of_phandle_args *reset_spec)
+{
+	struct mtk_clk_rst_data *data = to_mtk_clk_rst_data(rcdev);
+
+	if (reset_spec->args[0] >= rcdev->nr_resets ||
+	    reset_spec->args[0] >= data->desc->rst_idx_map_nr)
+		return -EINVAL;
+
+	return data->desc->rst_idx_map[reset_spec->args[0]];
+}
+
 void mtk_register_reset_controller(struct device_node *np,
 				   const struct mtk_clk_rst_desc *desc)
 {
@@ -136,10 +148,17 @@ void mtk_register_reset_controller(struct device_node *np,
 	data->desc = desc;
 	data->regmap = regmap;
 	data->rcdev.owner = THIS_MODULE;
-	data->rcdev.nr_resets = desc->rst_bank_nr * RST_NR_PER_BANK;
 	data->rcdev.ops = rcops;
 	data->rcdev.of_node = np;
 
+	if (data->desc->rst_idx_map_nr > 0) {
+		data->rcdev.of_reset_n_cells = 1;
+		data->rcdev.nr_resets = desc->rst_idx_map_nr;
+		data->rcdev.of_xlate = reset_xlate;
+	} else {
+		data->rcdev.nr_resets = desc->rst_bank_nr * RST_NR_PER_BANK;
+	}
+
 	ret = reset_controller_register(&data->rcdev);
 	if (ret) {
 		pr_err("could not register reset controller: %d\n", ret);