soundwire: intel: start using hw_ops

Before introducing new hardware with completely different register
spaces and programming sequences, we need to abstract some of the
existing routines in hw_ops that will be platform-specific. For now we
only use the 'cnl' ops - after the first Intel platform with SoundWire
capabilities.

Rather than one big intrusive patch, hw_ops are introduced in this
patch so show the dependencies between drivers. Follow-up patches will
introduce callbacks for debugfs, power and bus management.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20221111013135.38289-2-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/soundwire/intel.c

@@ -745,10 +745,10 @@ static int intel_free_stream(struct sdw_intel *sdw,
  * bank switch routines
  */
 
-static int intel_pre_bank_switch(struct sdw_bus *bus)
+static int intel_pre_bank_switch(struct sdw_intel *sdw)
 {
-	struct sdw_cdns *cdns = bus_to_cdns(bus);
-	struct sdw_intel *sdw = cdns_to_intel(cdns);
+	struct sdw_cdns *cdns = &sdw->cdns;
+	struct sdw_bus *bus = &cdns->bus;
 
 	/* Write to register only for multi-link */
 	if (!bus->multi_link)
@@ -759,10 +759,10 @@ static int intel_pre_bank_switch(struct sdw_bus *bus)
 	return 0;
 }
 
-static int intel_post_bank_switch(struct sdw_bus *bus)
+static int intel_post_bank_switch(struct sdw_intel *sdw)
 {
-	struct sdw_cdns *cdns = bus_to_cdns(bus);
-	struct sdw_intel *sdw = cdns_to_intel(cdns);
+	struct sdw_cdns *cdns = &sdw->cdns;
+	struct sdw_bus *bus = &cdns->bus;
 	void __iomem *shim = sdw->link_res->shim;
 	int sync_reg, ret;
 
@@ -1422,6 +1422,28 @@ static int intel_stop_bus(struct sdw_intel *sdw, bool clock_stop)
 	return 0;
 }
 
+const struct sdw_intel_hw_ops sdw_intel_cnl_hw_ops = {
+	.pre_bank_switch = intel_pre_bank_switch,
+	.post_bank_switch = intel_post_bank_switch,
+};
+EXPORT_SYMBOL_NS(sdw_intel_cnl_hw_ops, SOUNDWIRE_INTEL);
+
+static int generic_pre_bank_switch(struct sdw_bus *bus)
+{
+	struct sdw_cdns *cdns = bus_to_cdns(bus);
+	struct sdw_intel *sdw = cdns_to_intel(cdns);
+
+	return sdw->link_res->hw_ops->pre_bank_switch(sdw);
+}
+
+static int generic_post_bank_switch(struct sdw_bus *bus)
+{
+	struct sdw_cdns *cdns = bus_to_cdns(bus);
+	struct sdw_intel *sdw = cdns_to_intel(cdns);
+
+	return sdw->link_res->hw_ops->post_bank_switch(sdw);
+}
+
 static int sdw_master_read_intel_prop(struct sdw_bus *bus)
 {
 	struct sdw_master_prop *prop = &bus->prop;
@@ -1477,8 +1499,8 @@ static struct sdw_master_ops sdw_intel_ops = {
 	.xfer_msg_defer = cdns_xfer_msg_defer,
 	.reset_page_addr = cdns_reset_page_addr,
 	.set_bus_conf = cdns_bus_conf,
-	.pre_bank_switch = intel_pre_bank_switch,
-	.post_bank_switch = intel_post_bank_switch,
+	.pre_bank_switch = generic_pre_bank_switch,
+	.post_bank_switch = generic_post_bank_switch,
 	.read_ping_status = cdns_read_ping_status,
 };
 

drivers/soundwire/intel.h

@@ -7,6 +7,7 @@
 /**
  * struct sdw_intel_link_res - Soundwire Intel link resource structure,
  * typically populated by the controller driver.
+ * @hw_ops: platform-specific ops
  * @mmio_base: mmio base of SoundWire registers
  * @registers: Link IO registers base
  * @shim: Audio shim pointer
@@ -22,6 +23,8 @@
  * @list: used to walk-through all masters exposed by the same controller
  */
 struct sdw_intel_link_res {
+	const struct sdw_intel_hw_ops *hw_ops;
+
 	void __iomem *mmio_base; /* not strictly needed, useful for debug */
 	void __iomem *registers;
 	void __iomem *shim;

drivers/soundwire/intel_init.c

@@ -60,6 +60,7 @@ static struct sdw_intel_link_dev *intel_link_dev_register(struct sdw_intel_res *
 
 	/* Add link information used in the driver probe */
 	link = &ldev->link_res;
+	link->hw_ops = res->hw_ops;
 	link->mmio_base = res->mmio_base;
 	link->registers = res->mmio_base + SDW_LINK_BASE
 		+ (SDW_LINK_SIZE * link_id);

include/linux/soundwire/sdw_intel.h

@@ -233,6 +233,7 @@ struct sdw_intel_ctx {
  * struct sdw_intel_res - Soundwire Intel global resource structure,
  * typically populated by the DSP driver
  *
+ * @hw_ops: abstraction for platform ops
  * @count: link count
  * @mmio_base: mmio base of SoundWire registers
  * @irq: interrupt number
@@ -249,6 +250,7 @@ struct sdw_intel_ctx {
  * @alh_base: sdw alh base.
  */
 struct sdw_intel_res {
+	const struct sdw_intel_hw_ops *hw_ops;
 	int count;
 	void __iomem *mmio_base;
 	int irq;
@@ -292,4 +294,17 @@ irqreturn_t sdw_intel_thread(int irq, void *dev_id);
 
 #define SDW_INTEL_QUIRK_MASK_BUS_DISABLE      BIT(1)
 
+struct sdw_intel;
+
+/* struct intel_sdw_hw_ops - SoundWire ops for Intel platforms.
+ * @pre_bank_switch: helper for bus management
+ * @post_bank_switch: helper for bus management
+ */
+struct sdw_intel_hw_ops {
+	int (*pre_bank_switch)(struct sdw_intel *sdw);
+	int (*post_bank_switch)(struct sdw_intel *sdw);
+};
+
+extern const struct sdw_intel_hw_ops sdw_intel_cnl_hw_ops;
+
 #endif

sound/soc/sof/intel/hda.c

@@ -188,6 +188,7 @@ static int hda_sdw_probe(struct snd_sof_dev *sdev)
 
 	memset(&res, 0, sizeof(res));
 
+	res.hw_ops = &sdw_intel_cnl_hw_ops;
 	res.mmio_base = sdev->bar[HDA_DSP_BAR];
 	res.shim_base = hdev->desc->sdw_shim_base;
 	res.alh_base = hdev->desc->sdw_alh_base;
@@ -1694,3 +1695,4 @@ MODULE_IMPORT_NS(SND_SOC_SOF_HDA_AUDIO_CODEC_I915);
 MODULE_IMPORT_NS(SND_SOC_SOF_XTENSA);
 MODULE_IMPORT_NS(SND_INTEL_SOUNDWIRE_ACPI);
 MODULE_IMPORT_NS(SOUNDWIRE_INTEL_INIT);
+MODULE_IMPORT_NS(SOUNDWIRE_INTEL);