[PATCH v5 0/2] soundwire: Add support to Qualcomm SoundWire master

[PATCH v5 0/2] soundwire: Add support to Qualcomm SoundWire master

[Srinivas Kandagatla]

Thanks for reviewing the v4 patchset.
Here is new patchset addressing all the comments from v3

This patchset adds support for Qualcomm SoundWire Master Controller
found in most of Qualcomm SoCs and WCD audio codecs.

This driver along with WCD934x codec and WSA881x Class-D Smart Speaker
Amplifier drivers is tested on on DragonBoard DB845c based of SDM845
SoC and Lenovo YOGA C630 Laptop based on SDM850.

SoundWire controller on SDM845 is integrated in WCD934x audio codec via
SlimBus interface.

Currently this driver is very minimal and only supports PDM.

Most of the code in this driver is rework of Qualcomm downstream drivers
used in Andriod. Credits to Banajit Goswami and Patrick Lai's Team.

TODO:
	Test and add PCM support.

Thanks,
srini

Changes since v4:
	- moved stream handling to codec as there is a strong hw requirements
	 on port and PA enable sequence on codec side
	- removed dummy runtime pm 
	- cleaned up code as suggested by Pierre


Srinivas Kandagatla (2):
  dt-bindings: soundwire: add bindings for Qcom controller
  soundwire: qcom: add support for SoundWire controller

 .../bindings/soundwire/qcom,sdw.txt           | 167 ++++
 drivers/soundwire/Kconfig                     |   9 +
 drivers/soundwire/Makefile                    |   4 +
 drivers/soundwire/qcom.c                      | 856 ++++++++++++++++++
 4 files changed, 1036 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/soundwire/qcom,sdw.txt
 create mode 100644 drivers/soundwire/qcom.c

-- 
2.21.0

[PATCH v5 1/2] dt-bindings: soundwire: add bindings for Qcom controller

[Srinivas Kandagatla]

This patch adds bindings for Qualcomm soundwire controller.

Qualcomm SoundWire Master controller is present in most Qualcomm SoCs
either integrated as part of WCD audio codecs via slimbus or
as part of SOC I/O.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../bindings/soundwire/qcom,sdw.txt           | 167 ++++++++++++++++++
 1 file changed, 167 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/soundwire/qcom,sdw.txt

diff --git a/Documentation/devicetree/bindings/soundwire/qcom,sdw.txt b/Documentation/devicetree/bindings/soundwire/qcom,sdw.txt
new file mode 100644
index 000000000000..436547f3b155
--- /dev/null
+++ b/Documentation/devicetree/bindings/soundwire/qcom,sdw.txt
@@ -0,0 +1,167 @@
+Qualcomm SoundWire Controller Bindings
+
+
+This binding describes the Qualcomm SoundWire Controller along with its
+board specific bus parameters.
+
+- compatible:
+	Usage: required
+	Value type: <stringlist>
+	Definition: must be "qcom,soundwire-v<MAJOR>.<MINOR>.<STEP>",
+		    Example:
+			"qcom,soundwire-v1.3.0"
+			"qcom,soundwire-v1.5.0"
+			"qcom,soundwire-v1.6.0"
+- reg:
+	Usage: required
+	Value type: <prop-encoded-array>
+	Definition: the base address and size of SoundWire controller
+		    address space.
+
+- interrupts:
+	Usage: required
+	Value type: <prop-encoded-array>
+	Definition: should specify the SoundWire Controller IRQ
+
+- clock-names:
+	Usage: required
+	Value type: <stringlist>
+	Definition: should be "iface" for SoundWire Controller interface clock
+
+- clocks:
+	Usage: required
+	Value type: <prop-encoded-array>
+	Definition: should specify the SoundWire Controller interface clock
+
+- #sound-dai-cells:
+	Usage: required
+	Value type: <u32>
+	Definition: must be 1 for digital audio interfaces on the controller.
+
+- qcom,dout-ports:
+	Usage: required
+	Value type: <u32>
+	Definition: must be count of data out ports
+
+- qcom,din-ports:
+	Usage: required
+	Value type: <u32>
+	Definition: must be count of data in ports
+
+- qcom,ports-offset1:
+	Usage: required
+	Value type: <prop-encoded-array>
+	Definition: should specify payload transport window offset1 of each
+		    data port. Out ports followed by In ports.
+		    More info in MIPI Alliance SoundWire 1.0 Specifications.
+
+- qcom,ports-offset2:
+	Usage: required
+	Value type: <prop-encoded-array>
+	Definition: should specify payload transport window offset2 of each
+		    data port. Out ports followed by In ports.
+		    More info in MIPI Alliance SoundWire 1.0 Specifications.
+
+- qcom,ports-sinterval-low:
+	Usage: required
+	Value type: <prop-encoded-array>
+	Definition: should be sample interval low of each data port.
+		    Out ports followed by In ports. Used for Sample Interval
+		    calculation.
+		    More info in MIPI Alliance SoundWire 1.0 Specifications.
+
+- qcom,ports-word-length:
+	Usage: optional
+	Value type: <prop-encoded-array>
+	Definition: should be size of payload channel sample.
+		    More info in MIPI Alliance SoundWire 1.0 Specifications.
+
+- qcom,ports-block-pack-mode:
+	Usage: optional
+	Value type: <prop-encoded-array>
+	Definition: should be 0 or 1 to indicate the block packing mode.
+		    0 to indicate Blocks are per Channel
+		    1 to indicate Blocks are per Port.
+		    Out ports followed by In ports.
+		    More info in MIPI Alliance SoundWire 1.0 Specifications.
+
+- qcom,ports-block-group-count:
+	Usage: optional
+	Value type: <prop-encoded-array>
+	Definition: should be in range 1 to 4 to indicate how many sample
+		    intervals are combined into a payload.
+		    Out ports followed by In ports.
+		    More info in MIPI Alliance SoundWire 1.0 Specifications.
+
+- qcom,ports-lane-control:
+	Usage: optional
+	Value type: <prop-encoded-array>
+	Definition: should be in range 0 to 7 to identify which	data lane
+		    the data port uses.
+		    Out ports followed by In ports.
+		    More info in MIPI Alliance SoundWire 1.0 Specifications.
+
+- qcom,ports-hstart:
+	Usage: optional
+	Value type: <prop-encoded-array>
+	Definition: should be number identifying lowerst numbered coloum in
+		    SoundWire Frame, i.e. left edge of the Transport sub-frame
+		    for each port. Values between 0 and 15 are valid.
+		    Out ports followed by In ports.
+		    More info in MIPI Alliance SoundWire 1.0 Specifications.
+
+- qcom,ports-hstop:
+	Usage: optional
+	Value type: <prop-encoded-array>
+	Definition: should be number identifying highest numbered coloum in
+		    SoundWire Frame, i.e. the right edge of the Transport
+		    sub-frame for each port. Values between 0 and 15 are valid.
+		    Out ports followed by In ports.
+		    More info in MIPI Alliance SoundWire 1.0 Specifications.
+
+- qcom,dports-type:
+	Usage: optional
+	Value type: <prop-encoded-array>
+	Definition: should be one of the following types
+		    0 for reduced port
+		    1 for simple ports
+		    2 for full port
+		    Out ports followed by In ports.
+		    More info in MIPI Alliance SoundWire 1.0 Specifications.
+
+Note:
+	More Information on detail of encoding of these fields can be
+found in MIPI Alliance SoundWire 1.0 Specifications.
+
+= SoundWire devices
+Each subnode of the bus represents SoundWire device attached to it.
+The properties of these nodes are defined by the individual bindings.
+
+= EXAMPLE
+The following example represents a SoundWire controller on DB845c board
+which has controller integrated inside WCD934x codec on SDM845 SoC.
+
+soundwire: soundwire@c85 {
+	compatible = "qcom,soundwire-v1.3.0";
+	reg = <0xc85 0x20>;
+	interrupts = <20 IRQ_TYPE_EDGE_RISING>;
+	clocks = <&wcc>;
+	clock-names = "iface";
+	#sound-dai-cells = <1>;
+	qcom,dports-type = <0>;
+	qcom,dout-ports	= <6>;
+	qcom,din-ports	= <2>;
+	qcom,ports-sinterval-low = /bits/ 8  <0x07 0x1F 0x3F 0x7 0x1F 0x3F 0x0F 0x0F>;
+	qcom,ports-offset1 = /bits/ 8 <0x01 0x02 0x0C 0x6 0x12 0x0D 0x07 0x0A >;
+	qcom,ports-offset2 = /bits/ 8 <0x00 0x00 0x1F 0x00 0x00 0x1F 0x00 0x00>;
+
+	/* Left Speaker */
+	left{
+		....
+	};
+
+	/* Right Speaker */
+	right{
+		....
+	};
+};
-- 
2.21.0

[PATCH v5 2/2] soundwire: qcom: add support for SoundWire controller

[Srinivas Kandagatla]

Qualcomm SoundWire Master controller is present in most Qualcomm SoCs
either integrated as part of WCD audio codecs via slimbus or
as part of SOC I/O.

This patchset adds support to a very basic controller which has been
tested with WCD934x SoundWire controller connected to WSA881x smart
speaker amplifiers.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
---
 drivers/soundwire/Kconfig  |   9 +
 drivers/soundwire/Makefile |   4 +
 drivers/soundwire/qcom.c   | 856 +++++++++++++++++++++++++++++++++++++
 3 files changed, 869 insertions(+)
 create mode 100644 drivers/soundwire/qcom.c

diff --git a/drivers/soundwire/Kconfig b/drivers/soundwire/Kconfig
index c725d0a8b288..fa2b4ab92ed9 100644
--- a/drivers/soundwire/Kconfig
+++ b/drivers/soundwire/Kconfig
@@ -31,4 +31,13 @@ config SOUNDWIRE_INTEL
 	  enable this config option to get the SoundWire support for that
 	  device.
 
+config SOUNDWIRE_QCOM
+	tristate "Qualcomm SoundWire Master driver"
+	depends on SLIMBUS
+	depends on SND_SOC
+	help
+	  SoundWire Qualcomm Master driver.
+	  If you have an Qualcomm platform which has a SoundWire Master then
+	  enable this config option to get the SoundWire support for that
+	  device
 endif
diff --git a/drivers/soundwire/Makefile b/drivers/soundwire/Makefile
index 563894e5ecaf..e2cdff990e9f 100644
--- a/drivers/soundwire/Makefile
+++ b/drivers/soundwire/Makefile
@@ -21,3 +21,7 @@ obj-$(CONFIG_SOUNDWIRE_INTEL) += soundwire-intel.o
 
 soundwire-intel-init-objs := intel_init.o
 obj-$(CONFIG_SOUNDWIRE_INTEL) += soundwire-intel-init.o
+
+#Qualcomm driver
+soundwire-qcom-objs :=	qcom.o
+obj-$(CONFIG_SOUNDWIRE_QCOM) += soundwire-qcom.o
diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
new file mode 100644
index 000000000000..98a7076db4ef
--- /dev/null
+++ b/drivers/soundwire/qcom.c
@@ -0,0 +1,856 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2019, Linaro Limited
+
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/slimbus.h>
+#include <linux/soundwire/sdw.h>
+#include <linux/soundwire/sdw_registers.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+#include "bus.h"
+
+#define SWRM_COMP_HW_VERSION					0x00
+#define SWRM_COMP_CFG_ADDR					0x04
+#define SWRM_COMP_CFG_IRQ_LEVEL_OR_PULSE_MSK			BIT(1)
+#define SWRM_COMP_CFG_ENABLE_MSK				BIT(0)
+#define SWRM_COMP_PARAMS					0x100
+#define SWRM_COMP_PARAMS_DOUT_PORTS_MASK			GENMASK(4, 0)
+#define SWRM_COMP_PARAMS_DIN_PORTS_MASK				GENMASK(9, 5)
+#define SWRM_INTERRUPT_STATUS					0x200
+#define SWRM_INTERRUPT_STATUS_RMSK				GENMASK(16, 0)
+#define SWRM_INTERRUPT_STATUS_NEW_SLAVE_ATTACHED		BIT(1)
+#define SWRM_INTERRUPT_STATUS_CHANGE_ENUM_SLAVE_STATUS		BIT(2)
+#define SWRM_INTERRUPT_STATUS_CMD_ERROR				BIT(7)
+#define SWRM_INTERRUPT_STATUS_SPECIAL_CMD_ID_FINISHED		BIT(10)
+#define SWRM_INTERRUPT_MASK_ADDR				0x204
+#define SWRM_INTERRUPT_CLEAR					0x208
+#define SWRM_CMD_FIFO_WR_CMD					0x300
+#define SWRM_CMD_FIFO_RD_CMD					0x304
+#define SWRM_CMD_FIFO_CMD					0x308
+#define SWRM_CMD_FIFO_STATUS					0x30C
+#define SWRM_CMD_FIFO_CFG_ADDR					0x314
+#define SWRM_RD_WR_CMD_RETRIES					0x7
+#define SWRM_CMD_FIFO_RD_FIFO_ADDR				0x318
+#define SWRM_ENUMERATOR_CFG_ADDR				0x500
+#define SWRM_MCP_FRAME_CTRL_BANK_ADDR(m)		(0x101C + 0x40 * (m))
+#define SWRM_MCP_FRAME_CTRL_BANK_ROW_CTRL_SHFT			3
+#define SWRM_MCP_FRAME_CTRL_BANK_COL_CTRL_BMSK			GENMASK(2, 0)
+#define SWRM_MCP_FRAME_CTRL_BANK_ROW_CTRL_BMSK			GENMASK(7, 3)
+#define SWRM_MCP_FRAME_CTRL_BANK_COL_CTRL_SHFT			0
+#define SWRM_MCP_CFG_ADDR					0x1048
+#define SWRM_MCP_CFG_MAX_NUM_OF_CMD_NO_PINGS_BMSK		GENMASK(21, 17)
+#define SWRM_MCP_CFG_MAX_NUM_OF_CMD_NO_PINGS_SHFT		0x11
+#define SWRM_DEF_CMD_NO_PINGS					0x1f
+#define SWRM_MCP_STATUS						0x104C
+#define SWRM_MCP_STATUS_BANK_NUM_MASK				BIT(0)
+#define SWRM_MCP_SLV_STATUS					0x1090
+#define SWRM_MCP_SLV_STATUS_MASK				GENMASK(1, 0)
+#define SWRM_DP_PORT_CTRL_BANK(n, m)	(0x1124 + 0x100 * (n - 1) + 0x40 * m)
+#define SWRM_DP_PORT_CTRL_EN_CHAN_SHFT				0x18
+#define SWRM_DP_PORT_CTRL_OFFSET2_SHFT				0x10
+#define SWRM_DP_PORT_CTRL_OFFSET1_SHFT				0x08
+#define SWRM_AHB_BRIDGE_WR_DATA_0				0xc85
+#define SWRM_AHB_BRIDGE_WR_ADDR_0				0xc89
+#define SWRM_AHB_BRIDGE_RD_ADDR_0				0xc8d
+#define SWRM_AHB_BRIDGE_RD_DATA_0				0xc91
+
+#define SWRM_REG_VAL_PACK(data, dev, id, reg)	\
+			((reg) | ((id) << 16) | ((dev) << 20) | ((data) << 24))
+
+#define SWRM_MAX_ROW_VAL	0 /* Rows = 48 */
+#define SWRM_DEFAULT_ROWS	48
+#define SWRM_MIN_COL_VAL	0 /* Cols = 2 */
+#define SWRM_DEFAULT_COL	16
+#define SWRM_MAX_COL_VAL	7
+#define SWRM_SPECIAL_CMD_ID	0xF
+#define MAX_FREQ_NUM		1
+#define TIMEOUT_MS		(2 * HZ)
+#define QCOM_SWRM_MAX_RD_LEN	0xf
+#define QCOM_SDW_MAX_PORTS	14
+#define DEFAULT_CLK_FREQ	9600000
+#define SWRM_MAX_DAIS		0xF
+
+struct qcom_swrm_port_config {
+	u8 si;
+	u8 off1;
+	u8 off2;
+};
+
+struct qcom_swrm_ctrl {
+	struct sdw_bus bus;
+	struct device *dev;
+	struct regmap *regmap;
+	struct completion *comp;
+	struct work_struct slave_work;
+	/* read/write lock */
+	spinlock_t comp_lock;
+	/* Port alloc/free lock */
+	struct mutex port_lock;
+	struct clk *hclk;
+	u8 wr_cmd_id;
+	u8 rd_cmd_id;
+	int irq;
+	unsigned int version;
+	int num_din_ports;
+	int num_dout_ports;
+	unsigned long dout_port_mask;
+	unsigned long din_port_mask;
+	struct qcom_swrm_port_config pconfig[QCOM_SDW_MAX_PORTS];
+	struct sdw_stream_runtime *sruntime[SWRM_MAX_DAIS];
+	enum sdw_slave_status status[SDW_MAX_DEVICES];
+	int (*reg_read)(struct qcom_swrm_ctrl *ctrl, int reg, u32 *val);
+	int (*reg_write)(struct qcom_swrm_ctrl *ctrl, int reg, int val);
+};
+
+#define to_qcom_sdw(b)	container_of(b, struct qcom_swrm_ctrl, bus)
+
+static int qcom_swrm_abh_reg_read(struct qcom_swrm_ctrl *ctrl, int reg,
+				  u32 *val)
+{
+	struct regmap *wcd_regmap = ctrl->regmap;
+	int ret;
+
+	/* pg register + offset */
+	ret = regmap_bulk_write(wcd_regmap, SWRM_AHB_BRIDGE_RD_ADDR_0,
+			  (u8 *)&reg, 4);
+	if (ret < 0)
+		return SDW_CMD_FAIL;
+
+	ret = regmap_bulk_read(wcd_regmap, SWRM_AHB_BRIDGE_RD_DATA_0,
+			       val, 4);
+	if (ret < 0)
+		return SDW_CMD_FAIL;
+
+	return SDW_CMD_OK;
+}
+
+static int qcom_swrm_ahb_reg_write(struct qcom_swrm_ctrl *ctrl,
+				   int reg, int val)
+{
+	struct regmap *wcd_regmap = ctrl->regmap;
+	int ret;
+	/* pg register + offset */
+	ret = regmap_bulk_write(wcd_regmap, SWRM_AHB_BRIDGE_WR_DATA_0,
+			  (u8 *)&val, 4);
+	if (ret)
+		return SDW_CMD_FAIL;
+
+	/* write address register */
+	ret = regmap_bulk_write(wcd_regmap, SWRM_AHB_BRIDGE_WR_ADDR_0,
+			  (u8 *)&reg, 4);
+	if (ret)
+		return SDW_CMD_FAIL;
+
+	return SDW_CMD_OK;
+}
+
+static int qcom_swrm_cmd_fifo_wr_cmd(struct qcom_swrm_ctrl *ctrl, u8 cmd_data,
+				     u8 dev_addr, u16 reg_addr)
+{
+	DECLARE_COMPLETION_ONSTACK(comp);
+	unsigned long flags;
+	u32 val;
+	int ret;
+
+	spin_lock_irqsave(&ctrl->comp_lock, flags);
+	ctrl->comp = &comp;
+	spin_unlock_irqrestore(&ctrl->comp_lock, flags);
+	val = SWRM_REG_VAL_PACK(cmd_data, dev_addr,
+				SWRM_SPECIAL_CMD_ID, reg_addr);
+	ret = ctrl->reg_write(ctrl, SWRM_CMD_FIFO_WR_CMD, val);
+	if (ret)
+		goto err;
+
+	ret = wait_for_completion_timeout(ctrl->comp,
+					  msecs_to_jiffies(TIMEOUT_MS));
+
+	if (!ret)
+		ret = SDW_CMD_IGNORED;
+	else
+		ret = SDW_CMD_OK;
+err:
+	spin_lock_irqsave(&ctrl->comp_lock, flags);
+	ctrl->comp = NULL;
+	spin_unlock_irqrestore(&ctrl->comp_lock, flags);
+
+	return ret;
+}
+
+static int qcom_swrm_cmd_fifo_rd_cmd(struct qcom_swrm_ctrl *ctrl,
+				     u8 dev_addr, u16 reg_addr,
+				     u32 len, u8 *rval)
+{
+	int i, ret;
+	u32 val;
+	DECLARE_COMPLETION_ONSTACK(comp);
+	unsigned long flags;
+
+	spin_lock_irqsave(&ctrl->comp_lock, flags);
+	ctrl->comp = &comp;
+	spin_unlock_irqrestore(&ctrl->comp_lock, flags);
+
+	val = SWRM_REG_VAL_PACK(len, dev_addr, SWRM_SPECIAL_CMD_ID, reg_addr);
+	ret = ctrl->reg_write(ctrl, SWRM_CMD_FIFO_RD_CMD, val);
+	if (ret)
+		goto err;
+
+	ret = wait_for_completion_timeout(ctrl->comp,
+					  msecs_to_jiffies(TIMEOUT_MS));
+
+	if (!ret) {
+		ret = SDW_CMD_IGNORED;
+		goto err;
+	} else {
+		ret = SDW_CMD_OK;
+	}
+
+	for (i = 0; i < len; i++) {
+		ctrl->reg_read(ctrl, SWRM_CMD_FIFO_RD_FIFO_ADDR, &val);
+		rval[i] = val & 0xFF;
+	}
+
+err:
+	spin_lock_irqsave(&ctrl->comp_lock, flags);
+	ctrl->comp = NULL;
+	spin_unlock_irqrestore(&ctrl->comp_lock, flags);
+
+	return ret;
+}
+
+static void qcom_swrm_get_device_status(struct qcom_swrm_ctrl *ctrl)
+{
+	u32 val;
+	int i;
+
+	ctrl->reg_read(ctrl, SWRM_MCP_SLV_STATUS, &val);
+
+	for (i = 0; i < SDW_MAX_DEVICES; i++) {
+		u32 s;
+
+		s = (val >> (i * 2));
+		s &= SWRM_MCP_SLV_STATUS_MASK;
+		ctrl->status[i] = s;
+	}
+}
+
+static irqreturn_t qcom_swrm_irq_handler(int irq, void *dev_id)
+{
+	struct qcom_swrm_ctrl *ctrl = dev_id;
+	u32 sts, value;
+	unsigned long flags;
+
+	ctrl->reg_read(ctrl, SWRM_INTERRUPT_STATUS, &sts);
+
+	if (sts & SWRM_INTERRUPT_STATUS_CMD_ERROR) {
+		ctrl->reg_read(ctrl, SWRM_CMD_FIFO_STATUS, &value);
+		dev_err_ratelimited(ctrl->dev,
+				    "CMD error, fifo status 0x%x\n",
+				     value);
+		ctrl->reg_write(ctrl, SWRM_CMD_FIFO_CMD, 0x1);
+	}
+
+	if ((sts & SWRM_INTERRUPT_STATUS_NEW_SLAVE_ATTACHED) ||
+	    sts & SWRM_INTERRUPT_STATUS_CHANGE_ENUM_SLAVE_STATUS)
+		schedule_work(&ctrl->slave_work);
+
+	ctrl->reg_write(ctrl, SWRM_INTERRUPT_CLEAR, sts);
+
+	if (sts & SWRM_INTERRUPT_STATUS_SPECIAL_CMD_ID_FINISHED) {
+		spin_lock_irqsave(&ctrl->comp_lock, flags);
+		if (ctrl->comp)
+			complete(ctrl->comp);
+		spin_unlock_irqrestore(&ctrl->comp_lock, flags);
+	}
+
+	return IRQ_HANDLED;
+}
+static int qcom_swrm_init(struct qcom_swrm_ctrl *ctrl)
+{
+	u32 val;
+
+	/* Clear Rows and Cols */
+	val = (SWRM_MAX_ROW_VAL << SWRM_MCP_FRAME_CTRL_BANK_ROW_CTRL_SHFT |
+	       SWRM_MIN_COL_VAL << SWRM_MCP_FRAME_CTRL_BANK_COL_CTRL_SHFT);
+
+	ctrl->reg_write(ctrl, SWRM_MCP_FRAME_CTRL_BANK_ADDR(0), val);
+
+	/* Disable Auto enumeration */
+	ctrl->reg_write(ctrl, SWRM_ENUMERATOR_CFG_ADDR, 0);
+
+	/* Mask soundwire interrupts */
+	ctrl->reg_write(ctrl, SWRM_INTERRUPT_MASK_ADDR,
+			SWRM_INTERRUPT_STATUS_RMSK);
+
+	/* Configure No pings */
+	ctrl->reg_read(ctrl, SWRM_MCP_CFG_ADDR, &val);
+	val &= ~SWRM_MCP_CFG_MAX_NUM_OF_CMD_NO_PINGS_BMSK;
+	val |= (SWRM_DEF_CMD_NO_PINGS <<
+		SWRM_MCP_CFG_MAX_NUM_OF_CMD_NO_PINGS_SHFT);
+	ctrl->reg_write(ctrl, SWRM_MCP_CFG_ADDR, val);
+
+	/* Configure number of retries of a read/write cmd */
+	ctrl->reg_write(ctrl, SWRM_CMD_FIFO_CFG_ADDR, SWRM_RD_WR_CMD_RETRIES);
+
+	/* Set IRQ to PULSE */
+	ctrl->reg_write(ctrl, SWRM_COMP_CFG_ADDR,
+			SWRM_COMP_CFG_IRQ_LEVEL_OR_PULSE_MSK |
+			SWRM_COMP_CFG_ENABLE_MSK);
+	return 0;
+}
+
+static enum sdw_command_response qcom_swrm_xfer_msg(struct sdw_bus *bus,
+						    struct sdw_msg *msg)
+{
+	struct qcom_swrm_ctrl *ctrl = to_qcom_sdw(bus);
+	int ret, i, len;
+
+	if (msg->flags == SDW_MSG_FLAG_READ) {
+		for (i = 0; i < msg->len;) {
+			if ((msg->len - i) < QCOM_SWRM_MAX_RD_LEN)
+				len = msg->len - i;
+			else
+				len = QCOM_SWRM_MAX_RD_LEN;
+
+			ret = qcom_swrm_cmd_fifo_rd_cmd(ctrl, msg->dev_num,
+							msg->addr + i, len,
+						       &msg->buf[i]);
+			if (ret)
+				return ret;
+
+			i = i + len;
+		}
+	} else if (msg->flags == SDW_MSG_FLAG_WRITE) {
+		for (i = 0; i < msg->len; i++) {
+			ret = qcom_swrm_cmd_fifo_wr_cmd(ctrl, msg->buf[i],
+							msg->dev_num,
+						       msg->addr + i);
+			if (ret)
+				return SDW_CMD_IGNORED;
+		}
+	}
+
+	return SDW_CMD_OK;
+}
+
+static int qcom_swrm_pre_bank_switch(struct sdw_bus *bus)
+{
+	u32 reg = SWRM_MCP_FRAME_CTRL_BANK_ADDR(bus->params.next_bank);
+	struct qcom_swrm_ctrl *ctrl = to_qcom_sdw(bus);
+	u32 val;
+
+	ctrl->reg_read(ctrl, reg, &val);
+
+	val &= ~SWRM_MCP_FRAME_CTRL_BANK_COL_CTRL_BMSK;
+	val &= ~SWRM_MCP_FRAME_CTRL_BANK_ROW_CTRL_BMSK;
+
+	val |= (SWRM_MAX_ROW_VAL << SWRM_MCP_FRAME_CTRL_BANK_ROW_CTRL_SHFT |
+		SWRM_MAX_COL_VAL << SWRM_MCP_FRAME_CTRL_BANK_COL_CTRL_SHFT);
+
+	return ctrl->reg_write(ctrl, reg, val);
+}
+
+static int qcom_swrm_port_params(struct sdw_bus *bus,
+				 struct sdw_port_params *p_params,
+				 unsigned int bank)
+{
+	/* TBD */
+	return 0;
+}
+
+static int qcom_swrm_transport_params(struct sdw_bus *bus,
+				      struct sdw_transport_params *params,
+				      enum sdw_reg_bank bank)
+{
+	struct qcom_swrm_ctrl *ctrl = to_qcom_sdw(bus);
+	u32 value;
+
+	value = params->offset1 << SWRM_DP_PORT_CTRL_OFFSET1_SHFT;
+	value |= params->offset2 << SWRM_DP_PORT_CTRL_OFFSET2_SHFT;
+	value |= params->sample_interval - 1;
+
+	return ctrl->reg_write(ctrl,
+			       SWRM_DP_PORT_CTRL_BANK((params->port_num), bank),
+			       value);
+}
+
+static int qcom_swrm_port_enable(struct sdw_bus *bus,
+				 struct sdw_enable_ch *enable_ch,
+				 unsigned int bank)
+{
+	u32 reg = SWRM_DP_PORT_CTRL_BANK(enable_ch->port_num, bank);
+	struct qcom_swrm_ctrl *ctrl = to_qcom_sdw(bus);
+	u32 val;
+
+	ctrl->reg_read(ctrl, reg, &val);
+
+	if (enable_ch->enable)
+		val |= (enable_ch->ch_mask << SWRM_DP_PORT_CTRL_EN_CHAN_SHFT);
+	else
+		val &= ~(0xff << SWRM_DP_PORT_CTRL_EN_CHAN_SHFT);
+
+	return ctrl->reg_write(ctrl, reg, val);
+}
+
+static struct sdw_master_port_ops qcom_swrm_port_ops = {
+	.dpn_set_port_params = qcom_swrm_port_params,
+	.dpn_set_port_transport_params = qcom_swrm_transport_params,
+	.dpn_port_enable_ch = qcom_swrm_port_enable,
+};
+
+static struct sdw_master_ops qcom_swrm_ops = {
+	.xfer_msg = qcom_swrm_xfer_msg,
+	.pre_bank_switch = qcom_swrm_pre_bank_switch,
+};
+
+static int qcom_swrm_compute_params(struct sdw_bus *bus)
+{
+	struct qcom_swrm_ctrl *ctrl = to_qcom_sdw(bus);
+	struct sdw_master_runtime *m_rt;
+	struct sdw_slave_runtime *s_rt;
+	struct sdw_port_runtime *p_rt;
+	struct qcom_swrm_port_config *pcfg;
+	int i = 0;
+
+	list_for_each_entry(m_rt, &bus->m_rt_list, bus_node) {
+		list_for_each_entry(p_rt, &m_rt->port_list, port_node) {
+			pcfg = &ctrl->pconfig[p_rt->num - 1];
+			p_rt->transport_params.port_num = p_rt->num;
+			p_rt->transport_params.sample_interval = pcfg->si + 1;
+			p_rt->transport_params.offset1 = pcfg->off1;
+			p_rt->transport_params.offset2 = pcfg->off2;
+		}
+
+		list_for_each_entry(s_rt, &m_rt->slave_rt_list, m_rt_node) {
+			list_for_each_entry(p_rt, &s_rt->port_list, port_node) {
+				pcfg = &ctrl->pconfig[i];
+				p_rt->transport_params.port_num = p_rt->num;
+				p_rt->transport_params.sample_interval =
+					pcfg->si + 1;
+				p_rt->transport_params.offset1 = pcfg->off1;
+				p_rt->transport_params.offset2 = pcfg->off2;
+				i++;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static u32 qcom_swrm_freq_tbl[MAX_FREQ_NUM] = {
+	DEFAULT_CLK_FREQ,
+};
+
+static void qcom_swrm_slave_wq(struct work_struct *work)
+{
+	struct qcom_swrm_ctrl *ctrl =
+			container_of(work, struct qcom_swrm_ctrl, slave_work);
+
+	qcom_swrm_get_device_status(ctrl);
+	sdw_handle_slave_status(&ctrl->bus, ctrl->status);
+}
+
+
+static void qcom_swrm_stream_free_ports(struct qcom_swrm_ctrl *ctrl,
+					struct sdw_stream_runtime *stream)
+{
+	struct sdw_master_runtime *m_rt;
+	struct sdw_port_runtime *p_rt;
+	unsigned long *port_mask;
+
+	mutex_lock(&ctrl->port_lock);
+
+	list_for_each_entry(m_rt, &stream->master_list, stream_node) {
+		if (m_rt->direction == SDW_DATA_DIR_RX)
+			port_mask = &ctrl->dout_port_mask;
+		else
+			port_mask = &ctrl->din_port_mask;
+
+		list_for_each_entry(p_rt, &m_rt->port_list, port_node)
+			clear_bit(p_rt->num - 1, port_mask);
+	}
+
+	mutex_unlock(&ctrl->port_lock);
+}
+
+static int qcom_swrm_stream_alloc_ports(struct qcom_swrm_ctrl *ctrl,
+					struct sdw_stream_runtime *stream,
+				       struct snd_pcm_hw_params *params,
+				       int direction)
+{
+	struct sdw_port_config pconfig[QCOM_SDW_MAX_PORTS];
+	struct sdw_stream_config sconfig;
+	struct sdw_master_runtime *m_rt;
+	struct sdw_slave_runtime *s_rt;
+	struct sdw_port_runtime *p_rt;
+	unsigned long *port_mask;
+	int i, maxport, pn, nports = 0, ret = 0;
+
+	mutex_lock(&ctrl->port_lock);
+	list_for_each_entry(m_rt, &stream->master_list, stream_node) {
+		if (m_rt->direction == SDW_DATA_DIR_RX) {
+			maxport = ctrl->num_dout_ports;
+			port_mask = &ctrl->dout_port_mask;
+		} else {
+			maxport = ctrl->num_din_ports;
+			port_mask = &ctrl->din_port_mask;
+		}
+
+		list_for_each_entry(s_rt, &m_rt->slave_rt_list, m_rt_node) {
+			list_for_each_entry(p_rt, &s_rt->port_list, port_node) {
+				/* Port numbers start from 1 - 14*/
+				pn = find_first_zero_bit(port_mask, maxport);
+				if (pn > (maxport - 1)) {
+					dev_err(ctrl->dev, "All ports busy\n");
+					ret = -EBUSY;
+					goto err;
+				}
+				set_bit(pn, port_mask);
+				pconfig[nports].num = pn + 1;
+				pconfig[nports].ch_mask = p_rt->ch_mask;
+				nports++;
+			}
+		}
+	}
+
+	if (direction == SNDRV_PCM_STREAM_CAPTURE)
+		sconfig.direction = SDW_DATA_DIR_TX;
+	else
+		sconfig.direction = SDW_DATA_DIR_RX;
+
+	/* hw parameters wil be ignored as we only support PDM */
+	sconfig.ch_count = 1;
+	sconfig.frame_rate = params_rate(params);
+	sconfig.type = stream->type;
+	sconfig.bps = 1;
+	sdw_stream_add_master(&ctrl->bus, &sconfig, pconfig,
+			      nports, stream);
+err:
+	if (ret) {
+		for (i = 0; i < nports; i++)
+			clear_bit(pconfig[i].num - 1, port_mask);
+	}
+
+	mutex_unlock(&ctrl->port_lock);
+
+	return ret;
+}
+
+static int qcom_swrm_hw_params(struct snd_pcm_substream *substream,
+			       struct snd_pcm_hw_params *params,
+			      struct snd_soc_dai *dai)
+{
+	struct qcom_swrm_ctrl *ctrl = dev_get_drvdata(dai->dev);
+	struct sdw_stream_runtime *sruntime = ctrl->sruntime[dai->id];
+	int ret;
+
+	ret = qcom_swrm_stream_alloc_ports(ctrl, sruntime, params,
+					   substream->stream);
+	if (ret)
+		qcom_swrm_stream_free_ports(ctrl, sruntime);
+
+	return ret;
+}
+
+static int qcom_swrm_hw_free(struct snd_pcm_substream *substream,
+			     struct snd_soc_dai *dai)
+{
+	struct qcom_swrm_ctrl *ctrl = dev_get_drvdata(dai->dev);
+	struct sdw_stream_runtime *sruntime = ctrl->sruntime[dai->id];
+
+	qcom_swrm_stream_free_ports(ctrl, sruntime);
+	sdw_stream_remove_master(&ctrl->bus, sruntime);
+
+	return 0;
+}
+
+static int qcom_swrm_set_sdw_stream(struct snd_soc_dai *dai,
+				    void *stream, int direction)
+{
+	struct qcom_swrm_ctrl *ctrl = dev_get_drvdata(dai->dev);
+
+	ctrl->sruntime[dai->id] = stream;
+
+	return 0;
+}
+
+static int qcom_swrm_startup(struct snd_pcm_substream *substream,
+			     struct snd_soc_dai *dai)
+{
+	struct qcom_swrm_ctrl *ctrl = dev_get_drvdata(dai->dev);
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct sdw_stream_runtime *sruntime;
+	int ret, i;
+
+	sruntime = sdw_alloc_stream(dai->name);
+	if (!sruntime)
+		return -ENOMEM;
+
+	ctrl->sruntime[dai->id] = sruntime;
+
+	for (i = 0; i < rtd->num_codecs; i++) {
+		ret = snd_soc_dai_set_sdw_stream(rtd->codec_dais[i], sruntime,
+						 substream->stream);
+		if (ret < 0 && ret != -ENOTSUPP) {
+			dev_err(dai->dev, "Failed to set sdw stream on %s",
+				rtd->codec_dais[i]->name);
+			sdw_release_stream(sruntime);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static void qcom_swrm_shutdown(struct snd_pcm_substream *substream,
+			       struct snd_soc_dai *dai)
+{
+	struct qcom_swrm_ctrl *ctrl = dev_get_drvdata(dai->dev);
+
+	sdw_release_stream(ctrl->sruntime[dai->id]);
+	ctrl->sruntime[dai->id] = NULL;
+}
+
+static const struct snd_soc_dai_ops qcom_swrm_pdm_dai_ops = {
+	.hw_params = qcom_swrm_hw_params,
+	.hw_free = qcom_swrm_hw_free,
+	.startup = qcom_swrm_startup,
+	.shutdown = qcom_swrm_shutdown,
+	.set_sdw_stream = qcom_swrm_set_sdw_stream,
+};
+
+static const struct snd_soc_component_driver qcom_swrm_dai_component = {
+	.name = "soundwire",
+};
+
+static int qcom_swrm_register_dais(struct qcom_swrm_ctrl *ctrl)
+{
+	int num_dais = ctrl->num_dout_ports + ctrl->num_din_ports;
+	struct snd_soc_dai_driver *dais;
+	struct snd_soc_pcm_stream *stream;
+	struct device *dev = ctrl->dev;
+	int i;
+
+	/* PDM dais are only tested for now */
+	dais = devm_kcalloc(dev, num_dais, sizeof(*dais), GFP_KERNEL);
+	if (!dais)
+		return -ENOMEM;
+
+	for (i = 0; i < num_dais; i++) {
+		dais[i].name = devm_kasprintf(dev, GFP_KERNEL, "SDW Pin%d", i);
+		if (!dais[i].name)
+			return -ENOMEM;
+
+		if (i < ctrl->num_dout_ports)
+			stream = &dais[i].playback;
+		else
+			stream = &dais[i].capture;
+
+		stream->channels_min = 1;
+		stream->channels_max = 1;
+		stream->rates = SNDRV_PCM_RATE_48000;
+		stream->formats = SNDRV_PCM_FMTBIT_S16_LE;
+
+		dais[i].ops = &qcom_swrm_pdm_dai_ops;
+		dais[i].id = i;
+	}
+
+	return devm_snd_soc_register_component(ctrl->dev,
+						&qcom_swrm_dai_component,
+						dais, num_dais);
+}
+
+static int qcom_swrm_get_port_config(struct qcom_swrm_ctrl *ctrl)
+{
+	struct device_node *np = ctrl->dev->of_node;
+	u8 off1[QCOM_SDW_MAX_PORTS];
+	u8 off2[QCOM_SDW_MAX_PORTS];
+	u8 si[QCOM_SDW_MAX_PORTS];
+	int i, ret, nports, val;
+
+	ctrl->reg_read(ctrl, SWRM_COMP_PARAMS, &val);
+
+	ctrl->num_dout_ports = val & SWRM_COMP_PARAMS_DOUT_PORTS_MASK;
+	ctrl->num_din_ports = (val & SWRM_COMP_PARAMS_DIN_PORTS_MASK) >> 5;
+
+	ret = of_property_read_u32(np, "qcom,din-ports", &val);
+	if (ret)
+		return ret;
+
+	if (val > ctrl->num_din_ports)
+		return -EINVAL;
+
+	ctrl->num_din_ports = val;
+
+	ret = of_property_read_u32(np, "qcom,dout-ports", &val);
+	if (ret)
+		return ret;
+
+	if (val > ctrl->num_dout_ports)
+		return -EINVAL;
+
+	ctrl->num_dout_ports = val;
+
+	nports = ctrl->num_dout_ports + ctrl->num_din_ports;
+
+	ret = of_property_read_u8_array(np, "qcom,ports-offset1",
+					off1, nports);
+	if (ret)
+		return ret;
+
+	ret = of_property_read_u8_array(np, "qcom,ports-offset2",
+					off2, nports);
+	if (ret)
+		return ret;
+
+	ret = of_property_read_u8_array(np, "qcom,ports-sinterval-low",
+					si, nports);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < nports; i++) {
+		ctrl->pconfig[i].si = si[i];
+		ctrl->pconfig[i].off1 = off1[i];
+		ctrl->pconfig[i].off2 = off2[i];
+	}
+
+	return 0;
+}
+
+static int qcom_swrm_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct sdw_master_prop *prop;
+	struct sdw_bus_params *params;
+	struct qcom_swrm_ctrl *ctrl;
+	int ret;
+	u32 val;
+
+	ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL);
+	if (!ctrl)
+		return -ENOMEM;
+
+	if (dev->parent->bus == &slimbus_bus) {
+		ctrl->reg_read = qcom_swrm_abh_reg_read;
+		ctrl->reg_write = qcom_swrm_ahb_reg_write;
+		ctrl->regmap = dev_get_regmap(dev->parent, NULL);
+		if (!ctrl->regmap)
+			return -EINVAL;
+	} else {
+		/* Only WCD based SoundWire controller is supported */
+		return -ENOTSUPP;
+	}
+
+	ctrl->irq = of_irq_get(dev->of_node, 0);
+	if (ctrl->irq < 0)
+		return ctrl->irq;
+
+	ctrl->hclk = devm_clk_get(dev, "iface");
+	if (IS_ERR(ctrl->hclk))
+		return PTR_ERR(ctrl->hclk);
+
+	clk_prepare_enable(ctrl->hclk);
+
+	ctrl->dev = dev;
+	dev_set_drvdata(&pdev->dev, ctrl);
+	spin_lock_init(&ctrl->comp_lock);
+	mutex_init(&ctrl->port_lock);
+	INIT_WORK(&ctrl->slave_work, qcom_swrm_slave_wq);
+
+	ctrl->bus.dev = dev;
+	ctrl->bus.ops = &qcom_swrm_ops;
+	ctrl->bus.port_ops = &qcom_swrm_port_ops;
+	ctrl->bus.compute_params = &qcom_swrm_compute_params;
+
+	ret = qcom_swrm_get_port_config(ctrl);
+	if (ret)
+		return ret;
+
+	params = &ctrl->bus.params;
+	params->max_dr_freq = DEFAULT_CLK_FREQ;
+	params->curr_dr_freq = DEFAULT_CLK_FREQ;
+	params->col = SWRM_DEFAULT_COL;
+	params->row = SWRM_DEFAULT_ROWS;
+	ctrl->reg_read(ctrl, SWRM_MCP_STATUS, &val);
+	params->curr_bank = val & SWRM_MCP_STATUS_BANK_NUM_MASK;
+	params->next_bank = !params->curr_bank;
+
+	prop = &ctrl->bus.prop;
+	prop->max_clk_freq = DEFAULT_CLK_FREQ;
+	prop->num_clk_gears = 0;
+	prop->num_clk_freq = MAX_FREQ_NUM;
+	prop->clk_freq = &qcom_swrm_freq_tbl[0];
+	prop->default_col = SWRM_DEFAULT_COL;
+	prop->default_row = SWRM_DEFAULT_ROWS;
+
+	ctrl->reg_read(ctrl, SWRM_COMP_HW_VERSION, &ctrl->version);
+
+	ret = devm_request_threaded_irq(dev, ctrl->irq, NULL,
+					qcom_swrm_irq_handler,
+					IRQF_TRIGGER_RISING,
+					"soundwire", ctrl);
+	if (ret) {
+		dev_err(dev, "Failed to request soundwire irq\n");
+		goto err;
+	}
+
+	ret = sdw_add_bus_master(&ctrl->bus);
+	if (ret) {
+		dev_err(dev, "Failed to register Soundwire controller (%d)\n",
+			ret);
+		goto err;
+	}
+
+	qcom_swrm_init(ctrl);
+	ret = qcom_swrm_register_dais(ctrl);
+	if (ret)
+		goto err;
+
+	dev_info(dev, "Qualcomm Soundwire controller v%x.%x.%x Registered\n",
+		 (ctrl->version >> 24) & 0xff, (ctrl->version >> 16) & 0xff,
+		 ctrl->version & 0xffff);
+
+	return 0;
+err:
+	clk_disable_unprepare(ctrl->hclk);
+	return ret;
+}
+
+static int qcom_swrm_remove(struct platform_device *pdev)
+{
+	struct qcom_swrm_ctrl *ctrl = dev_get_drvdata(&pdev->dev);
+
+	sdw_delete_bus_master(&ctrl->bus);
+	clk_disable_unprepare(ctrl->hclk);
+
+	return 0;
+}
+
+static const struct of_device_id qcom_swrm_of_match[] = {
+	{ .compatible = "qcom,soundwire-v1.3.0", },
+	{/* sentinel */},
+};
+
+MODULE_DEVICE_TABLE(of, qcom_swrm_of_match);
+
+static struct platform_driver qcom_swrm_driver = {
+	.probe	= &qcom_swrm_probe,
+	.remove = &qcom_swrm_remove,
+	.driver = {
+		.name	= "qcom-soundwire",
+		.of_match_table = qcom_swrm_of_match,
+	}
+};
+module_platform_driver(qcom_swrm_driver);
+
+MODULE_DESCRIPTION("Qualcomm soundwire driver");
+MODULE_LICENSE("GPL v2");
-- 
2.21.0

Re: [alsa-devel] [PATCH v5 2/2] soundwire: qcom: add support for SoundWire controller

[Pierre-Louis Bossart]

On 12/19/19 3:28 AM, Srinivas Kandagatla wrote:
> Qualcomm SoundWire Master controller is present in most Qualcomm SoCs
> either integrated as part of WCD audio codecs via slimbus or
> as part of SOC I/O.
> 
> This patchset adds support to a very basic controller which has been
> tested with WCD934x SoundWire controller connected to WSA881x smart
> speaker amplifiers.
> 
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

This looks quite good, I only have a couple of nit-picks/questions below.
> +static int qcom_swrm_abh_reg_read(struct qcom_swrm_ctrl *ctrl, int reg,
> +				  u32 *val)
> +{
> +	struct regmap *wcd_regmap = ctrl->regmap;
> +	int ret;
> +
> +	/* pg register + offset */
> +	ret = regmap_bulk_write(wcd_regmap, SWRM_AHB_BRIDGE_RD_ADDR_0,
> +			  (u8 *)&reg, 4);
> +	if (ret < 0)
> +		return SDW_CMD_FAIL;
> +
> +	ret = regmap_bulk_read(wcd_regmap, SWRM_AHB_BRIDGE_RD_DATA_0,
> +			       val, 4);
> +	if (ret < 0)
> +		return SDW_CMD_FAIL;
> +
> +	return SDW_CMD_OK;
> +}

I think I asked the question before but don't remember the answer so you 
may want to add a comment explaining why SDW_CMD_IGNORED is not a 
possible return value?

The BER is supposed to be very very low but there is a non-zero 
possibility of a device losing sync.

> +
> +static int qcom_swrm_ahb_reg_write(struct qcom_swrm_ctrl *ctrl,
> +				   int reg, int val)
> +{
> +	struct regmap *wcd_regmap = ctrl->regmap;
> +	int ret;
> +	/* pg register + offset */
> +	ret = regmap_bulk_write(wcd_regmap, SWRM_AHB_BRIDGE_WR_DATA_0,
> +			  (u8 *)&val, 4);
> +	if (ret)
> +		return SDW_CMD_FAIL;
> +
> +	/* write address register */
> +	ret = regmap_bulk_write(wcd_regmap, SWRM_AHB_BRIDGE_WR_ADDR_0,
> +			  (u8 *)&reg, 4);
> +	if (ret)
> +		return SDW_CMD_FAIL;
> +
> +	return SDW_CMD_OK;
> +}

same here, how is a CMD_IGNORED case handled?

> +
> +static int qcom_swrm_cmd_fifo_wr_cmd(struct qcom_swrm_ctrl *ctrl, u8 cmd_data,
> +				     u8 dev_addr, u16 reg_addr)
> +{
> +	DECLARE_COMPLETION_ONSTACK(comp);
> +	unsigned long flags;
> +	u32 val;
> +	int ret;
> +
> +	spin_lock_irqsave(&ctrl->comp_lock, flags);
> +	ctrl->comp = &comp;
> +	spin_unlock_irqrestore(&ctrl->comp_lock, flags);
> +	val = SWRM_REG_VAL_PACK(cmd_data, dev_addr,
> +				SWRM_SPECIAL_CMD_ID, reg_addr);
> +	ret = ctrl->reg_write(ctrl, SWRM_CMD_FIFO_WR_CMD, val);
> +	if (ret)
> +		goto err;

the code is a bit inconsistent at the moment on how errors are handled.
In some cases you explicitly test for errors, but ...


> +
> +	for (i = 0; i < len; i++) {
> +		ctrl->reg_read(ctrl, SWRM_CMD_FIFO_RD_FIFO_ADDR, &val);

... here you don't ...

> +		rval[i] = val & 0xFF;
> +	}
> +
> +err:
> +	spin_lock_irqsave(&ctrl->comp_lock, flags);
> +	ctrl->comp = NULL;
> +	spin_unlock_irqrestore(&ctrl->comp_lock, flags);
> +
> +	return ret;
> +}
> +
> +static void qcom_swrm_get_device_status(struct qcom_swrm_ctrl *ctrl)
> +{
> +	u32 val;
> +	int i;
> +
> +	ctrl->reg_read(ctrl, SWRM_MCP_SLV_STATUS, &val);

... and not here ...

> +
> +	for (i = 0; i < SDW_MAX_DEVICES; i++) {
> +		u32 s;
> +
> +		s = (val >> (i * 2));
> +		s &= SWRM_MCP_SLV_STATUS_MASK;
> +		ctrl->status[i] = s;
> +	}
> +}
> +
> +static irqreturn_t qcom_swrm_irq_handler(int irq, void *dev_id)
> +{
> +	struct qcom_swrm_ctrl *ctrl = dev_id;
> +	u32 sts, value;
> +	unsigned long flags;
> +
> +	ctrl->reg_read(ctrl, SWRM_INTERRUPT_STATUS, &sts);

... and here same the reg_read/writes are no longer tested for?

> +
> +	if (sts & SWRM_INTERRUPT_STATUS_CMD_ERROR) {
> +		ctrl->reg_read(ctrl, SWRM_CMD_FIFO_STATUS, &value);
> +		dev_err_ratelimited(ctrl->dev,
> +				    "CMD error, fifo status 0x%x\n",
> +				     value);
> +		ctrl->reg_write(ctrl, SWRM_CMD_FIFO_CMD, 0x1);
> +	}
> +
> +	if ((sts & SWRM_INTERRUPT_STATUS_NEW_SLAVE_ATTACHED) ||
> +	    sts & SWRM_INTERRUPT_STATUS_CHANGE_ENUM_SLAVE_STATUS)
> +		schedule_work(&ctrl->slave_work);
> +
> +	ctrl->reg_write(ctrl, SWRM_INTERRUPT_CLEAR, sts);

is it intentional to clear the interrupts first, before doing additional 
checks?

Or could it be done immediately after reading the status. It's not clear 
to me if the position of this clear matters, and if yes you should 
probably add a comment?

> +
> +	if (sts & SWRM_INTERRUPT_STATUS_SPECIAL_CMD_ID_FINISHED) {
> +		spin_lock_irqsave(&ctrl->comp_lock, flags);
> +		if (ctrl->comp)
> +			complete(ctrl->comp);
> +		spin_unlock_irqrestore(&ctrl->comp_lock, flags);
> +	}
> +
> +	return IRQ_HANDLED;
The rest looks fine. nice work.

Re: [alsa-devel] [PATCH v5 2/2] soundwire: qcom: add support for SoundWire controller

[Srinivas Kandagatla]

On 19/12/2019 16:07, Pierre-Louis Bossart wrote:
> 
> 
> On 12/19/19 3:28 AM, Srinivas Kandagatla wrote:
>> Qualcomm SoundWire Master controller is present in most Qualcomm SoCs
>> either integrated as part of WCD audio codecs via slimbus or
>> as part of SOC I/O.
>>
>> This patchset adds support to a very basic controller which has been
>> tested with WCD934x SoundWire controller connected to WSA881x smart
>> speaker amplifiers.
>>
>> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> 
> This looks quite good, I only have a couple of nit-picks/questions below.

Thanks for taking time to review this.

>> +static int qcom_swrm_abh_reg_read(struct qcom_swrm_ctrl *ctrl, int reg,
>> +                  u32 *val)
>> +{
>> +    struct regmap *wcd_regmap = ctrl->regmap;
>> +    int ret;
>> +
>> +    /* pg register + offset */
>> +    ret = regmap_bulk_write(wcd_regmap, SWRM_AHB_BRIDGE_RD_ADDR_0,
>> +              (u8 *)&reg, 4);
>> +    if (ret < 0)
>> +        return SDW_CMD_FAIL;
>> +
>> +    ret = regmap_bulk_read(wcd_regmap, SWRM_AHB_BRIDGE_RD_DATA_0,
>> +                   val, 4);
>> +    if (ret < 0)
>> +        return SDW_CMD_FAIL;
>> +
>> +    return SDW_CMD_OK;
>> +}
> 
> I think I asked the question before but don't remember the answer so you 
> may want to add a comment explaining why SDW_CMD_IGNORED is not a 
> possible return value?
> 
There is no way atleast in this version of the controller to know if the 
command is ignored. Only error that can be detected atm is timeout 
waiting for response. Hopefully new versions of this IP have that 
ability to detect this.

> The BER is supposed to be very very low but there is a non-zero 
> possibility of a device losing sync.
> 
>> +
>> +static int qcom_swrm_cmd_fifo_wr_cmd(struct qcom_swrm_ctrl *ctrl, u8 
>> cmd_data,
>> +                     u8 dev_addr, u16 reg_addr)
>> +{
>> +    DECLARE_COMPLETION_ONSTACK(comp);
>> +    unsigned long flags;
>> +    u32 val;
>> +    int ret;
>> +
>> +    spin_lock_irqsave(&ctrl->comp_lock, flags);
>> +    ctrl->comp = &comp;
>> +    spin_unlock_irqrestore(&ctrl->comp_lock, flags);
>> +    val = SWRM_REG_VAL_PACK(cmd_data, dev_addr,
>> +                SWRM_SPECIAL_CMD_ID, reg_addr);
>> +    ret = ctrl->reg_write(ctrl, SWRM_CMD_FIFO_WR_CMD, val);
>> +    if (ret)
>> +        goto err;
> 
> the code is a bit inconsistent at the moment on how errors are handled.
> In some cases you explicitly test for errors, but ...

I looked at our previous discussions and I think we decided not to do 
error checking reading on controller registers.

"For the Intel stuff, we typically don't check the read/writes to 
controller registers, but anything that goes out on the bus is checked. "
> 
> 
>> +
>> +    for (i = 0; i < len; i++) {
>> +        ctrl->reg_read(ctrl, SWRM_CMD_FIFO_RD_FIFO_ADDR, &val);
> 
> ... here you don't ...
> 
>> +        rval[i] = val & 0xFF;
>> +    }
>> +
>> +err:
>> +    spin_lock_irqsave(&ctrl->comp_lock, flags);
>> +    ctrl->comp = NULL;
>> +    spin_unlock_irqrestore(&ctrl->comp_lock, flags);
>> +
>> +    return ret;
>> +}
>> +
>> +static void qcom_swrm_get_device_status(struct qcom_swrm_ctrl *ctrl)
>> +{
>> +    u32 val;
>> +    int i;
>> +
>> +    ctrl->reg_read(ctrl, SWRM_MCP_SLV_STATUS, &val);
> 
> ... and not here ...
> 
>> +
>> +    for (i = 0; i < SDW_MAX_DEVICES; i++) {
>> +        u32 s;
>> +
>> +        s = (val >> (i * 2));
>> +        s &= SWRM_MCP_SLV_STATUS_MASK;
>> +        ctrl->status[i] = s;
>> +    }
>> +}
>> +
>> +static irqreturn_t qcom_swrm_irq_handler(int irq, void *dev_id)
>> +{
>> +    struct qcom_swrm_ctrl *ctrl = dev_id;
>> +    u32 sts, value;
>> +    unsigned long flags;
>> +
>> +    ctrl->reg_read(ctrl, SWRM_INTERRUPT_STATUS, &sts);
> 
> ... and here same the reg_read/writes are no longer tested for?
> 
>> +
>> +    if (sts & SWRM_INTERRUPT_STATUS_CMD_ERROR) {
>> +        ctrl->reg_read(ctrl, SWRM_CMD_FIFO_STATUS, &value);
>> +        dev_err_ratelimited(ctrl->dev,
>> +                    "CMD error, fifo status 0x%x\n",
>> +                     value);
>> +        ctrl->reg_write(ctrl, SWRM_CMD_FIFO_CMD, 0x1);
>> +    }
>> +
>> +    if ((sts & SWRM_INTERRUPT_STATUS_NEW_SLAVE_ATTACHED) ||
>> +        sts & SWRM_INTERRUPT_STATUS_CHANGE_ENUM_SLAVE_STATUS)
>> +        schedule_work(&ctrl->slave_work);
>> +
>> +    ctrl->reg_write(ctrl, SWRM_INTERRUPT_CLEAR, sts);
> 
> is it intentional to clear the interrupts first, before doing additional 
> checks?
> 

No, I can move it to right to the end!

> Or could it be done immediately after reading the status. It's not clear 
> to me if the position of this clear matters, and if yes you should 
> probably add a comment?

Am not 100% if it matters, but Ideally I would like clear the interrupt 
source before clearing the interrupt.


> 
>> +
>> +    if (sts & SWRM_INTERRUPT_STATUS_SPECIAL_CMD_ID_FINISHED) {
>> +        spin_lock_irqsave(&ctrl->comp_lock, flags);
>> +        if (ctrl->comp)
>> +            complete(ctrl->comp);
>> +        spin_unlock_irqrestore(&ctrl->comp_lock, flags);
>> +    }
>> +
>> +    return IRQ_HANDLED;
> The rest looks fine. nice work.
Thanks,
srini

Re: [alsa-devel] [PATCH v5 2/2] soundwire: qcom: add support for SoundWire controller

[Srinivas Kandagatla]

On 19/12/2019 17:14, Srinivas Kandagatla wrote:
>>> +
>>> +    if (sts & SWRM_INTERRUPT_STATUS_CMD_ERROR) {
>>> +        ctrl->reg_read(ctrl, SWRM_CMD_FIFO_STATUS, &value);
>>> +        dev_err_ratelimited(ctrl->dev,
>>> +                    "CMD error, fifo status 0x%x\n",
>>> +                     value);
>>> +        ctrl->reg_write(ctrl, SWRM_CMD_FIFO_CMD, 0x1);
>>> +    }
>>> +
>>> +    if ((sts & SWRM_INTERRUPT_STATUS_NEW_SLAVE_ATTACHED) ||
>>> +        sts & SWRM_INTERRUPT_STATUS_CHANGE_ENUM_SLAVE_STATUS)
>>> +        schedule_work(&ctrl->slave_work);
>>> +
>>> +    ctrl->reg_write(ctrl, SWRM_INTERRUPT_CLEAR, sts);
>>
>> is it intentional to clear the interrupts first, before doing 
>> additional checks?
>>
> 
> No, I can move it to right to the end!

Reason why I did this was that if we run complete() before irq is 
cleared complete might trigger another read/write which can raise an 
interrupt. And with interrupt status not cleared we might miss it. This 
is very much timing dependent specially with the threaded irq.

So code needs no change atm!

> 
>> Or could it be done immediately after reading the status. It's not 
>> clear to me if the position of this clear matters, and if yes you 
>> should probably add a comment?
> 
> Am not 100% if it matters, but Ideally I would like clear the interrupt 
> source before clearing the interrupt.
> 
> 
>>
>>> +
>>> +    if (sts & SWRM_INTERRUPT_STATUS_SPECIAL_CMD_ID_FINISHED) {
>>> +        spin_lock_irqsave(&ctrl->comp_lock, flags);
>>> +        if (ctrl->comp)
>>> +            complete(ctrl->comp);
>>> +        spin_unlock_irqrestore(&ctrl->comp_lock, flags);
>>> +    }
>>> +
>>> +    return IRQ_HANDLED;
>> The rest looks fine. nice work. 

Thanks,
srini

Re: [alsa-devel] [PATCH v5 2/2] soundwire: qcom: add support for SoundWire controller

[Pierre-Louis Bossart]

>>>> +    if (sts & SWRM_INTERRUPT_STATUS_CMD_ERROR) {
>>>> +        ctrl->reg_read(ctrl, SWRM_CMD_FIFO_STATUS, &value);
>>>> +        dev_err_ratelimited(ctrl->dev,
>>>> +                    "CMD error, fifo status 0x%x\n",
>>>> +                     value);
>>>> +        ctrl->reg_write(ctrl, SWRM_CMD_FIFO_CMD, 0x1);
>>>> +    }
>>>> +
>>>> +    if ((sts & SWRM_INTERRUPT_STATUS_NEW_SLAVE_ATTACHED) ||
>>>> +        sts & SWRM_INTERRUPT_STATUS_CHANGE_ENUM_SLAVE_STATUS)
>>>> +        schedule_work(&ctrl->slave_work);
>>>> +
>>>> +    ctrl->reg_write(ctrl, SWRM_INTERRUPT_CLEAR, sts);
>>>
>>> is it intentional to clear the interrupts first, before doing 
>>> additional checks?
>>>
>>
>> No, I can move it to right to the end!
> 
> Reason why I did this was that if we run complete() before irq is 
> cleared complete might trigger another read/write which can raise an 
> interrupt. And with interrupt status not cleared we might miss it. This 
> is very much timing dependent specially with the threaded irq.
> 
> So code needs no change atm!

ok, a comment to keep track of this timing dependency could help future 
generations then...