Re: [PATCH 2/3] soc: mediatek: cmdq-helper: add legacy GCE ISA support
From: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Date: 2026-07-28 15:08:57
Also in:
linux-devicetree, linux-mediatek, lkml
On 7/28/26 11:42, Roman Vivchar via B4 Relay wrote:
From: Roman Vivchar <redacted> Some SoCs, such as mt6572, have different WRITE and POLL instruction encoding. Instead of 16-bit offset and 8-bit subsystem ID, old GCEs have 22-bit offset and 2-bit subsystem ID.
What about poll_addr, mask, write_s, write_s_mask and others? Not sure that this will actually work reliably (though I'm sure you're not creating any regression).
quoted hunk ↗ jump to hunk
Extend cmdq_instruction struct with additional union and struct to hold the legacy format of instruction encoding. Add legacy_isa to select legacy GCE ISA when writing instruction. Finally, add special handing for legacy_isa cases. While mt6572 GCE supports 22-bit offsets, the parameter type for offset remains 16 bit, because all mt6572 GCE mmsys consumers are in the 0xffff range. Signed-off-by: Roman Vivchar <redacted> --- drivers/soc/mediatek/mtk-cmdq-helper.c | 55 ++++++++++++++++++++++---------- include/linux/mailbox/mtk-cmdq-mailbox.h | 1 + 2 files changed, 39 insertions(+), 17 deletions(-)diff --git a/drivers/soc/mediatek/mtk-cmdq-helper.c b/drivers/soc/mediatek/mtk-cmdq-helper.c index f8ee6c9ade89..094732405080 100644 --- a/drivers/soc/mediatek/mtk-cmdq-helper.c +++ b/drivers/soc/mediatek/mtk-cmdq-helper.c@@ -31,18 +31,27 @@ struct cmdq_instruction { }; }; union { - u16 offset; - u16 event; - u16 reg_dst; - }; - union { - u8 subsys; struct { - u8 sop:5; - u8 arg_c_t:1; - u8 src_t:1; - u8 dst_t:1; - }; + union { + u16 offset; + u16 event; + u16 reg_dst; + }; + union { + u8 subsys; + struct { + u8 sop:5; + u8 arg_c_t:1; + u8 src_t:1; + u8 dst_t:1; + }; + }; + } __packed; + + struct { + u32 offset_legacy:22; + u32 subsys_legacy:2; + } __packed; }; u8 op; };@@ -219,10 +228,16 @@ int cmdq_pkt_write(struct cmdq_pkt *pkt, u8 subsys, u16 offset, u32 value) { struct cmdq_instruction inst = { .op = CMDQ_CODE_WRITE, - .value = value, - .offset = offset, - .subsys = subsys + .value = value }; + + if (pkt->priv.legacy_isa) { + inst.offset_legacy = offset; + inst.subsys_legacy = subsys; + } else { + inst.offset = offset; + inst.subsys = subsys; + } return cmdq_pkt_append_command(pkt, inst); } EXPORT_SYMBOL(cmdq_pkt_write);@@ -459,10 +474,16 @@ int cmdq_pkt_poll(struct cmdq_pkt *pkt, u8 subsys, { struct cmdq_instruction inst = { .op = CMDQ_CODE_POLL, - .value = value, - .offset = offset, - .subsys = subsys + .value = value }; + + if (pkt->priv.legacy_isa) { + inst.offset_legacy = offset; + inst.subsys_legacy = subsys; + } else { + inst.offset = offset; + inst.subsys = subsys; + } return cmdq_pkt_append_command(pkt, inst); } EXPORT_SYMBOL(cmdq_pkt_poll);diff --git a/include/linux/mailbox/mtk-cmdq-mailbox.h b/include/linux/mailbox/mtk-cmdq-mailbox.h index 07c1bfbdb8c4..9fcebc4ca864 100644 --- a/include/linux/mailbox/mtk-cmdq-mailbox.h +++ b/include/linux/mailbox/mtk-cmdq-mailbox.h@@ -72,6 +72,7 @@ struct cmdq_cb_data { struct cmdq_mbox_priv { u8 shift_pa; + bool legacy_isa; dma_addr_t mminfra_offset; };