clk: mediatek: fhctl: Add support for older fhctl register layout

The Frequency Hopping Controller (FHCTL) seems to have different
versions, as it has a slightly different register layout on some
older SoCs like MT6795, MT8173, MT8183 (and others).

This driver is indeed compatible with at least some of those older
IP revisions, so all we need to do is to add a way to select the
right register layout at registration time.

Signed-off-by: AngeloGioacchino Del Regno <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Reviewed-by: Chen-Yu Tsai <[e-mail]>
Signed-off-by: Stephen Boyd <[e-mail]>

drivers/clk/mediatek/clk-fhctl.c

···
 #define PERCENT_TO_DDSLMT(dds, percent_m10) \
 	((((dds) * (percent_m10)) >> 5) / 100)
 
-static const struct fhctl_offset fhctl_offset = {
+const struct fhctl_offset fhctl_offset_v1 = {
+	.offset_hp_en = 0x0,
+	.offset_clk_con = 0x4,
+	.offset_rst_con = 0x8,
+	.offset_slope0 = 0xc,
+	.offset_slope1 = 0x10,
+	.offset_cfg = 0x0,
+	.offset_updnlmt = 0x4,
+	.offset_dds = 0x8,
+	.offset_dvfs = 0xc,
+	.offset_mon = 0x10,
+};
+
+const struct fhctl_offset fhctl_offset_v2 = {
 	.offset_hp_en = 0x0,
 	.offset_clk_con = 0x8,
 	.offset_rst_con = 0xc,
···
 	.offset_mon = 0x10,
 };
 
-const struct fhctl_offset *fhctl_get_offset_table(void)
+const struct fhctl_offset *fhctl_get_offset_table(enum fhctl_variant v)
 {
-	return &fhctl_offset;
+	switch (v) {
+	case FHCTL_PLLFH_V1:
+		return &fhctl_offset_v1;
+	case FHCTL_PLLFH_V2:
+		return &fhctl_offset_v2;
+	default:
+		return ERR_PTR(-EINVAL);
+	};
 }
 
 static void dump_hw(struct mtk_clk_pll *pll, struct fh_pll_regs *regs,

drivers/clk/mediatek/clk-fhctl.h

···
 #ifndef __CLK_FHCTL_H
 #define __CLK_FHCTL_H
 
+#include "clk-pllfh.h"
+
+enum fhctl_variant {
+	FHCTL_PLLFH_V1,
+	FHCTL_PLLFH_V2,
+};
+
 struct fhctl_offset {
 	u32 offset_hp_en;
 	u32 offset_clk_con;
···
 	u32 offset_dvfs;
 	u32 offset_mon;
 };
-const struct fhctl_offset *fhctl_get_offset_table(void);
+const struct fhctl_offset *fhctl_get_offset_table(enum fhctl_variant v);
 const struct fh_operation *fhctl_get_ops(void);
 void fhctl_hw_init(struct mtk_fh *fh);
 

drivers/clk/mediatek/clk-mt8186-apmixedsys.c

···
 #include <linux/platform_device.h>
 #include <dt-bindings/clock/mt8186-clk.h>
 
+#include "clk-fhctl.h"
 #include "clk-mtk.h"
 #include "clk-pll.h"
 #include "clk-pllfh.h"
···
 		.data = {						\
 			.pll_id = _pllid,				\
 			.fh_id = _fhid,					\
+			.fh_ver = FHCTL_PLLFH_V2,			\
 			.fhx_offset = _offset,				\
 			.dds_mask = GENMASK(21, 0),			\
 			.slope0_value = 0x6003c97,			\

drivers/clk/mediatek/clk-pllfh.c

···
 	}
 }
 
-static void pllfh_init(struct mtk_fh *fh, struct mtk_pllfh_data *pllfh_data)
+static int pllfh_init(struct mtk_fh *fh, struct mtk_pllfh_data *pllfh_data)
 {
 	struct fh_pll_regs *regs = &fh->regs;
 	const struct fhctl_offset *offset;
 	void __iomem *base = pllfh_data->state.base;
 	void __iomem *fhx_base = base + pllfh_data->data.fhx_offset;
 
-	offset = fhctl_get_offset_table();
+	offset = fhctl_get_offset_table(pllfh_data->data.fh_ver);
+	if (IS_ERR(offset))
+		return PTR_ERR(offset);
 
 	regs->reg_hp_en = base + offset->offset_hp_en;
 	regs->reg_clk_con = base + offset->offset_clk_con;
···
 	fh->lock = &pllfh_lock;
 
 	fh->ops = fhctl_get_ops();
+
+	return 0;
 }
 
 static bool fhctl_is_supported_and_enabled(const struct mtk_pllfh_data *pllfh)
···
 {
 	struct clk_hw *hw;
 	struct mtk_fh *fh;
+	int ret;
 
 	fh = kzalloc(sizeof(*fh), GFP_KERNEL);
 	if (!fh)
 		return ERR_PTR(-ENOMEM);
 
-	pllfh_init(fh, pllfh_data);
+	ret = pllfh_init(fh, pllfh_data);
+	if (ret) {
+		hw = ERR_PTR(ret);
+		goto out;
+	}
 
 	hw = mtk_clk_register_pll_ops(&fh->clk_pll, pll_data, base,
 				      &mtk_pllfh_ops);
 
 	if (IS_ERR(hw))
+		goto out;
+
+	fhctl_hw_init(fh);
+
+out:
+	if (IS_ERR(hw))
 		kfree(fh);
-	else
-		fhctl_hw_init(fh);
 
 	return hw;
 }

drivers/clk/mediatek/clk-pllfh.h

···
 struct fh_pll_data {
 	int pll_id;
 	int fh_id;
+	int fh_ver;
 	u32 fhx_offset;
 	u32 dds_mask;
 	u32 slope0_value;