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Date:   Tue, 2 Nov 2021 11:59:20 -0600
From:   Mathieu Poirier <mathieu.poirier@linaro.org>
To:     Tao Zhang <quic_taozha@quicinc.com>
Cc:     Suzuki K Poulose <suzuki.poulose@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Mike Leach <mike.leach@linaro.org>,
        Leo Yan <leo.yan@linaro.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org,
        Tingwei Zhang <quic_tingweiz@quicinc.com>,
        Mao Jinlong <quic_jinlmao@quicinc.com>,
        Yuanfang Zhang <quic_yuanfang@quicinc.com>,
        Trilok Soni <quic_tsoni@quicinc.com>
Subject: Re: [PATCH 03/10] Coresight: Add driver to support Coresight device
 TPDM
Message-ID: <20211102175920.GA325436@p14s>
References: <1634801936-15080-1-git-send-email-quic_taozha@quicinc.com>
 <1634801936-15080-4-git-send-email-quic_taozha@quicinc.com>
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In-Reply-To: <1634801936-15080-4-git-send-email-quic_taozha@quicinc.com>
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Good morning,


On Thu, Oct 21, 2021 at 03:38:49PM +0800, Tao Zhang wrote:
> Add driver to support Coresight device TPDM. This driver provides
> support for configuring monitor. Monitors are primarily responsible
> for data set collection and support the ability to collect any
> permutation of data set types. Monitors are also responsible for
> interaction with system cross triggering.

As far as I can tell there is nothing related to CTIs in this patch.  And if
there is, it is not documented.

> 
> Signed-off-by: Tao Zhang <quic_taozha@quicinc.com>
> ---
>  .../bindings/arm/coresight-tpdm.yaml          |  86 +++

As checkpatch says, this should be in a separate file.

>  MAINTAINERS                                   |   5 +

Since this is a coresight device Suzuki and I will continue the maintenance.
The get_maintainer script will make sure you care CC'ed on patches related to
the TPDM/TPDA drivers, and we would typically requried a "Reviewed-by" tag from
you before merging.

>  drivers/hwtracing/coresight/Kconfig           |   9 +
>  drivers/hwtracing/coresight/Makefile          |   1 +
>  drivers/hwtracing/coresight/coresight-tpdm.c  | 583 ++++++++++++++++++
>  5 files changed, 684 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/arm/coresight-tpdm.yaml
>  create mode 100644 drivers/hwtracing/coresight/coresight-tpdm.c
> 
> diff --git a/Documentation/devicetree/bindings/arm/coresight-tpdm.yaml b/Documentation/devicetree/bindings/arm/coresight-tpdm.yaml
> new file mode 100644
> index 000000000000..44541075d77f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/arm/coresight-tpdm.yaml
> @@ -0,0 +1,86 @@
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2021 Qualcomm Innovation Center, Inc. All rights reserved.
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/arm/coresight-tpdm.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Trace, Profiling and Diagnostics Monitor - TPDM
> +
> +description: |
> +  The TPDM or Monitor serves as data collection component for various dataset
> +  types specified in the QPMDA spec. It covers Basic Counts (BC), Tenure
> +  Counts (TC), Continuous Multi-Bit (CMB), and Discrete Single Bit (DSB). It
> +  performs data collection in the data producing clock domain and transfers it
> +  to the data collection time domain, generally ATB clock domain.
> +
> +  The primary use case of the TPDM is to collect data from different data
> +  sources and send it to a TPDA for packetization, timestamping, and funneling.
> +
> +maintainers:
> +  - Tao Zhang <quic_taozha@quicinc.com>
> +
> +properties:
> +  $nodename:
> +    pattern: "^tpdm(@[0-9a-f]+)$"
> +  compatible:
> +    items:
> +      - const: arm,primecell
> +
> +  reg:
> +    maxItems: 1
> +
> +  reg-names:
> +    items:
> +      - const: tpdm-base
> +
> +  atid:
> +    maxItems: 1
> +    description: |
> +      The QPMDA specification repurposed the ATID field of the AMBA ATB
> +      specification to use it to convey packetization information to the
> +      Aggregator.
> +
> +  out-ports:
> +    description: |
> +      Output connections from the TPDM to legacy CoreSight trace bus.
> +    $ref: /schemas/graph.yaml#/properties/ports
> +    properties:
> +      port:
> +        description: Output connection from the TPDM to legacy CoreSight
> +          Trace bus.
> +        $ref: /schemas/graph.yaml#/properties/port
> +
> +required:
> +  - compatible
> +  - reg
> +  - reg-names
> +  - atid
> +  - clocks
> +  - clock-names
> +
> +additionalProperties: false
> +
> +examples:
> +  # minimum TPDM definition.
> +  - |
> +    tpdm@6980000 {
> +      compatible = "arm,primecell";
> +      reg = <0x6980000 0x1000>;
> +      reg-names = "tpdm-base";
> +
> +      clocks = <&aoss_qmp>;
> +      clock-names = "apb_pclk";
> +
> +      atid = <78>;
> +      out-ports {
> +        port {
> +          tpdm_turing_out_funnel_turing: endpoint {
> +            remote-endpoint =
> +              <&funnel_turing_in_tpdm_turing>;
> +          };
> +        };
> +      };
> +    };
> +
> +...
> diff --git a/MAINTAINERS b/MAINTAINERS
> index eeb4c70b3d5b..cabecf760488 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -15303,6 +15303,11 @@ L:	netdev@vger.kernel.org
>  S:	Supported
>  F:	drivers/net/ipa/
>  
> +QCOM CORESIGHT TPDM DRIVER
> +M:	Tao Zhang <quic_taozha@quicinc.com>
> +S:	Maintained
> +F:	drivers/hwtracing/coresight/coresight-tpdm.c
> +
>  QEMU MACHINE EMULATOR AND VIRTUALIZER SUPPORT
>  M:	Gabriel Somlo <somlo@cmu.edu>
>  M:	"Michael S. Tsirkin" <mst@redhat.com>
> diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
> index f026e5c0e777..abe244a968f6 100644
> --- a/drivers/hwtracing/coresight/Kconfig
> +++ b/drivers/hwtracing/coresight/Kconfig
> @@ -188,4 +188,13 @@ config CORESIGHT_TRBE
>  
>  	  To compile this driver as a module, choose M here: the module will be
>  	  called coresight-trbe.
> +
> +config CORESIGHT_TPDM
> +	tristate "CoreSight Trace, Profiling & Diagnostics Monitor driver"
> +	select CORESIGHT_LINKS_AND_SINKS
> +	help
> +	  This driver provides support for configuring monitor. Monitors are
> +	  primarily responsible for data set collection and support the
> +	  ability to collect any permutation of data set types. Monitors are
> +	  also responsible for interaction with system cross triggering.

You also need to indicate what the name of the module would be.  Please look at
other extries in the Kconfig file for examples.

>  endif
> diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile
> index b6c4a48140ec..e7392a0dddeb 100644
> --- a/drivers/hwtracing/coresight/Makefile
> +++ b/drivers/hwtracing/coresight/Makefile
> @@ -25,5 +25,6 @@ obj-$(CONFIG_CORESIGHT_CPU_DEBUG) += coresight-cpu-debug.o
>  obj-$(CONFIG_CORESIGHT_CATU) += coresight-catu.o
>  obj-$(CONFIG_CORESIGHT_CTI) += coresight-cti.o
>  obj-$(CONFIG_CORESIGHT_TRBE) += coresight-trbe.o
> +obj-$(CONFIG_CORESIGHT_TPDM) += coresight-tpdm.o
>  coresight-cti-y := coresight-cti-core.o	coresight-cti-platform.o \
>  		   coresight-cti-sysfs.o
> diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
> new file mode 100644
> index 000000000000..906776c859d6
> --- /dev/null
> +++ b/drivers/hwtracing/coresight/coresight-tpdm.c
> @@ -0,0 +1,583 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2021 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/device.h>
> +#include <linux/amba/bus.h>
> +#include <linux/io.h>
> +#include <linux/err.h>
> +#include <linux/fs.h>
> +#include <linux/bitmap.h>
> +#include <linux/of.h>
> +#include <linux/coresight.h>
> +#include <linux/regulator/consumer.h>

These should be in alphabetical order.

> +
> +#include "coresight-priv.h"
> +
> +#define tpdm_writel(drvdata, val, off)	__raw_writel((val), drvdata->base + off)
> +#define tpdm_readl(drvdata, off)		__raw_readl(drvdata->base + off)

writel/readl_relaxed() are defines for __raw_writel/readl and as such the above
should not be needed.

> +
> +#define TPDM_LOCK(drvdata)						\
> +do {									\
> +	mb(); /* ensure configuration take effect before we lock it */	\
> +	tpdm_writel(drvdata, 0x0, CORESIGHT_LAR);			\
> +} while (0)
> +#define TPDM_UNLOCK(drvdata)						\
> +do {									\
> +	tpdm_writel(drvdata, CORESIGHT_UNLOCK, CORESIGHT_LAR);		\
> +	mb(); /* ensure unlock take effect before we configure */	\
> +} while (0)

That too isn't needed.  Simply use CS_LOCK/UNLOCK().

> +
> +/* GPR Registers */
> +#define TPDM_GPR_CR(n)		(0x0 + (n * 4))
> +
> +/* BC Subunit Registers */
> +#define TPDM_BC_CR		(0x280)
> +#define TPDM_BC_SATROLL		(0x284)
> +#define TPDM_BC_CNTENSET	(0x288)
> +#define TPDM_BC_CNTENCLR	(0x28C)
> +#define TPDM_BC_INTENSET	(0x290)
> +#define TPDM_BC_INTENCLR	(0x294)
> +#define TPDM_BC_TRIG_LO(n)	(0x298 + (n * 4))
> +#define TPDM_BC_TRIG_HI(n)	(0x318 + (n * 4))
> +#define TPDM_BC_GANG		(0x398)
> +#define TPDM_BC_OVERFLOW(n)	(0x39C + (n * 4))
> +#define TPDM_BC_OVSR		(0x3C0)
> +#define TPDM_BC_SELR		(0x3C4)
> +#define TPDM_BC_CNTR_LO		(0x3C8)
> +#define TPDM_BC_CNTR_HI		(0x3CC)
> +#define TPDM_BC_SHADOW_LO(n)	(0x3D0 + (n * 4))
> +#define TPDM_BC_SHADOW_HI(n)	(0x450 + (n * 4))
> +#define TPDM_BC_SWINC		(0x4D0)
> +#define TPDM_BC_MSR(n)		(0x4F0 + (n * 4))
> +
> +/* TC Subunit Registers */
> +#define TPDM_TC_CR		(0x500)
> +#define TPDM_TC_CNTENSET	(0x504)
> +#define TPDM_TC_CNTENCLR	(0x508)
> +#define TPDM_TC_INTENSET	(0x50C)
> +#define TPDM_TC_INTENCLR	(0x510)
> +#define TPDM_TC_TRIG_SEL(n)	(0x514 + (n * 4))
> +#define TPDM_TC_TRIG_LO(n)	(0x534 + (n * 4))
> +#define TPDM_TC_TRIG_HI(n)	(0x554 + (n * 4))
> +#define TPDM_TC_OVSR_GP		(0x580)
> +#define TPDM_TC_OVSR_IMPL	(0x584)
> +#define TPDM_TC_SELR		(0x588)
> +#define TPDM_TC_CNTR_LO		(0x58C)
> +#define TPDM_TC_CNTR_HI		(0x590)
> +#define TPDM_TC_SHADOW_LO(n)	(0x594 + (n * 4))
> +#define TPDM_TC_SHADOW_HI(n)	(0x644 + (n * 4))
> +#define TPDM_TC_SWINC		(0x700)
> +#define TPDM_TC_MSR(n)		(0x768 + (n * 4))
> +
> +/* DSB Subunit Registers */
> +#define TPDM_DSB_CR		(0x780)
> +#define TPDM_DSB_TIER		(0x784)
> +#define TPDM_DSB_TPR(n)		(0x788 + (n * 4))
> +#define TPDM_DSB_TPMR(n)	(0x7A8 + (n * 4))
> +#define TPDM_DSB_XPR(n)		(0x7C8 + (n * 4))
> +#define TPDM_DSB_XPMR(n)	(0x7E8 + (n * 4))
> +#define TPDM_DSB_EDCR(n)	(0x808 + (n * 4))
> +#define TPDM_DSB_EDCMR(n)	(0x848 + (n * 4))
> +#define TPDM_DSB_CA_SELECT(n)	(0x86c + (n * 4))
> +#define TPDM_DSB_MSR(n)		(0x980 + (n * 4))
> +
> +/* CMB/MCMB Subunit Registers */
> +#define TPDM_CMB_CR		(0xA00)
> +#define TPDM_CMB_TIER		(0xA04)
> +#define TPDM_CMB_TPR(n)		(0xA08 + (n * 4))
> +#define TPDM_CMB_TPMR(n)	(0xA10 + (n * 4))
> +#define TPDM_CMB_XPR(n)		(0xA18 + (n * 4))
> +#define TPDM_CMB_XPMR(n)	(0xA20 + (n * 4))
> +#define TPDM_CMB_MARKR		(0xA28)
> +#define TPDM_CMB_READCTL	(0xA70)
> +#define TPDM_CMB_READVAL	(0xA74)
> +#define TPDM_CMB_MSR(n)		(0xA80 + (n * 4))
> +
> +/* TPDM Specific Registers */
> +#define TPDM_ITATBCNTRL		(0xEF0)
> +#define TPDM_CLK_CTRL		(0x220)
> +#define TPDM_ITCNTRL		(0xF00)
> +
> +
> +#define TPDM_DATASETS		32
> +#define TPDM_BC_MAX_COUNTERS	32
> +#define TPDM_BC_MAX_OVERFLOW	6
> +#define TPDM_BC_MAX_MSR		4
> +#define TPDM_TC_MAX_COUNTERS	44
> +#define TPDM_TC_MAX_TRIG	8
> +#define TPDM_TC_MAX_MSR		6
> +#define TPDM_DSB_MAX_PATT	8
> +#define TPDM_DSB_MAX_SELECT	8
> +#define TPDM_DSB_MAX_MSR	32
> +#define TPDM_DSB_MAX_EDCR	16
> +#define TPDM_DSB_MAX_LINES	256
> +#define TPDM_CMB_PATT_CMP	2
> +#define TPDM_CMB_MAX_MSR	128
> +#define TPDM_MCMB_MAX_LANES	8
> +
> +/* DSB programming modes */
> +#define TPDM_DSB_MODE_CYCACC(val)	BMVAL(val, 0, 2)
> +#define TPDM_DSB_MODE_PERF		BIT(3)
> +#define TPDM_DSB_MODE_HPBYTESEL(val)	BMVAL(val, 4, 8)
> +#define TPDM_MODE_ALL			(0xFFFFFFF)
> +
> +#define NUM_OF_BITS		32
> +#define TPDM_GPR_REGS_MAX	160
> +
> +#define TPDM_TRACE_ID_START	128
> +
> +#define TPDM_REVISION_A		0
> +#define TPDM_REVISION_B		1
> +
> +#define HW_ENABLE_CHECK_VALUE   0x10
> +
> +

Extra newline

> +#define ATBCNTRL_VAL_32		0xC00F1409
> +#define ATBCNTRL_VAL_64		0xC01F1409
> +

All of the above should be in a header file.

> +
> +enum tpdm_dataset {
> +	TPDM_DS_IMPLDEF,
> +	TPDM_DS_DSB,
> +	TPDM_DS_CMB,
> +	TPDM_DS_TC,
> +	TPDM_DS_BC,
> +	TPDM_DS_GPR,
> +	TPDM_DS_MCMB,
> +};
> +
> +enum tpdm_mode {
> +	TPDM_MODE_ATB,
> +	TPDM_MODE_APB,
> +};
> +
> +enum tpdm_support_type {
> +	TPDM_SUPPORT_TYPE_FULL,
> +	TPDM_SUPPORT_TYPE_PARTIAL,
> +	TPDM_SUPPORT_TYPE_NO,
> +};
> +
> +enum tpdm_cmb_patt_bits {
> +	TPDM_CMB_LSB,
> +	TPDM_CMB_MSB,
> +};

These too.

> +
> +#ifdef CONFIG_CORESIGHT_TPDM_DEFAULT_ENABLE
> +static int boot_enable = 1;
> +#else
> +static int boot_enable;
> +#endif

That isn't the proper way to do this.  Look at how it is done in
coresight-etm4x.c

> +
> +struct gpr_dataset {
> +	DECLARE_BITMAP(gpr_dirty, TPDM_GPR_REGS_MAX);
> +	uint32_t		gp_regs[TPDM_GPR_REGS_MAX];

Shouldn't this be u32?

> +};
> +
> +struct bc_dataset {
> +	enum tpdm_mode		capture_mode;
> +	enum tpdm_mode		retrieval_mode;
> +	uint32_t		sat_mode;
> +	uint32_t		enable_counters;
> +	uint32_t		clear_counters;
> +	uint32_t		enable_irq;
> +	uint32_t		clear_irq;
> +	uint32_t		trig_val_lo[TPDM_BC_MAX_COUNTERS];
> +	uint32_t		trig_val_hi[TPDM_BC_MAX_COUNTERS];
> +	uint32_t		enable_ganging;
> +	uint32_t		overflow_val[TPDM_BC_MAX_OVERFLOW];
> +	uint32_t		msr[TPDM_BC_MAX_MSR];
> +};
> +
> +struct tc_dataset {
> +	enum tpdm_mode		capture_mode;
> +	enum tpdm_mode		retrieval_mode;
> +	bool			sat_mode;
> +	uint32_t		enable_counters;
> +	uint32_t		clear_counters;
> +	uint32_t		enable_irq;
> +	uint32_t		clear_irq;
> +	uint32_t		trig_sel[TPDM_TC_MAX_TRIG];
> +	uint32_t		trig_val_lo[TPDM_TC_MAX_TRIG];
> +	uint32_t		trig_val_hi[TPDM_TC_MAX_TRIG];
> +	uint32_t		msr[TPDM_TC_MAX_MSR];
> +};
> +
> +struct dsb_dataset {
> +	uint32_t		mode;
> +	uint32_t		edge_ctrl[TPDM_DSB_MAX_EDCR];
> +	uint32_t		edge_ctrl_mask[TPDM_DSB_MAX_EDCR / 2];
> +	uint32_t		patt_val[TPDM_DSB_MAX_PATT];
> +	uint32_t		patt_mask[TPDM_DSB_MAX_PATT];
> +	bool			patt_ts;
> +	bool			patt_type;
> +	uint32_t		trig_patt_val[TPDM_DSB_MAX_PATT];
> +	uint32_t		trig_patt_mask[TPDM_DSB_MAX_PATT];
> +	bool			trig_ts;
> +	bool			trig_type;
> +	uint32_t		select_val[TPDM_DSB_MAX_SELECT];
> +	uint32_t		msr[TPDM_DSB_MAX_MSR];
> +};
> +
> +struct mcmb_dataset {
> +	uint8_t		mcmb_trig_lane;
> +	uint8_t		mcmb_lane_select;
> +};
> +
> +struct cmb_dataset {
> +	bool			trace_mode;
> +	uint32_t		cycle_acc;
> +	uint32_t		patt_val[TPDM_CMB_PATT_CMP];
> +	uint32_t		patt_mask[TPDM_CMB_PATT_CMP];
> +	bool			patt_ts;
> +	uint32_t		trig_patt_val[TPDM_CMB_PATT_CMP];
> +	uint32_t		trig_patt_mask[TPDM_CMB_PATT_CMP];
> +	bool			trig_ts;
> +	bool			ts_all;
> +	uint32_t		msr[TPDM_CMB_MAX_MSR];
> +	uint8_t			read_ctl_reg;
> +	struct mcmb_dataset	*mcmb;
> +};
> +
> +DEFINE_CORESIGHT_DEVLIST(tpdm_devs, "tpdm");
> +
> +struct tpdm_drvdata {
> +	void __iomem		*base;
> +	struct device		*dev;
> +	struct coresight_device	*csdev;
> +	int			nr_tclk;
> +	struct clk		**tclk;
> +	int			nr_treg;
> +	struct regulator	**treg;
> +	struct mutex		lock;
> +	bool			enable;
> +	bool			clk_enable;
> +	DECLARE_BITMAP(datasets, TPDM_DATASETS);
> +	DECLARE_BITMAP(enable_ds, TPDM_DATASETS);
> +	enum tpdm_support_type	tc_trig_type;
> +	enum tpdm_support_type	bc_trig_type;
> +	enum tpdm_support_type	bc_gang_type;
> +	uint32_t		bc_counters_avail;
> +	uint32_t		tc_counters_avail;
> +	struct gpr_dataset	*gpr;
> +	struct bc_dataset	*bc;
> +	struct tc_dataset	*tc;
> +	struct dsb_dataset	*dsb;
> +	struct cmb_dataset	*cmb;
> +	int			traceid;
> +	uint32_t		version;
> +	bool			msr_support;
> +	bool			msr_fix_req;
> +	bool			cmb_msr_skip;
> +};

All of these should also be in a header file and properly documented.

> +
> +static void tpdm_init_default_data(struct tpdm_drvdata *drvdata);

This isn't needed.

> +
> +static void __tpdm_enable(struct tpdm_drvdata *drvdata)
> +{
> +	TPDM_UNLOCK(drvdata);
> +
> +	if (drvdata->clk_enable)
> +		tpdm_writel(drvdata, 0x1, TPDM_CLK_CTRL);
> +
> +	TPDM_LOCK(drvdata);
> +}
> +
> +static int tpdm_enable(struct coresight_device *csdev,
> +		       struct perf_event *event, u32 mode)
> +{
> +	struct tpdm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
> +	int ret = 0;
> +
> +	if (drvdata->enable) {

This a race condition.

> +		dev_err(drvdata->dev,
> +			"TPDM setup already enabled,Skipping enablei\n");

Please remove this.

> +		return ret;

Shouldn't this be return -EBUSY? 

> +	}
> +
> +	mutex_lock(&drvdata->lock);
> +	__tpdm_enable(drvdata);
> +	drvdata->enable = true;
> +	mutex_unlock(&drvdata->lock);
> +
> +	dev_info(drvdata->dev, "TPDM tracing enabled\n");
> +	return 0;
> +}
> +
> +static void __tpdm_disable(struct tpdm_drvdata *drvdata)
> +{
> +	TPDM_UNLOCK(drvdata);
> +
> +	if (drvdata->clk_enable)
> +		tpdm_writel(drvdata, 0x0, TPDM_CLK_CTRL);
> +
> +	TPDM_LOCK(drvdata);
> +}
> +
> +static void tpdm_disable(struct coresight_device *csdev,
> +			 struct perf_event *event)
> +{
> +	struct tpdm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
> +
> +	if (!drvdata->enable) {
> +		dev_err(drvdata->dev,
> +			"TPDM setup already disabled, Skipping disable\n");
> +		return;
> +	}
> +	mutex_lock(&drvdata->lock);
> +	__tpdm_disable(drvdata);
> +	drvdata->enable = false;
> +	mutex_unlock(&drvdata->lock);

Same comments as above.

> +
> +	dev_info(drvdata->dev, "TPDM tracing disabled\n");
> +}
> +
> +static int tpdm_trace_id(struct coresight_device *csdev)
> +{
> +	struct tpdm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
> +
> +	return drvdata->traceid;
> +}
> +
> +static const struct coresight_ops_source tpdm_source_ops = {
> +	.trace_id	= tpdm_trace_id,
> +	.enable		= tpdm_enable,
> +	.disable	= tpdm_disable,
> +};
> +
> +static const struct coresight_ops tpdm_cs_ops = {
> +	.source_ops	= &tpdm_source_ops,
> +};
> +
> +static int tpdm_datasets_alloc(struct tpdm_drvdata *drvdata)
> +{
> +	if (test_bit(TPDM_DS_GPR, drvdata->datasets)) {
> +		drvdata->gpr = devm_kzalloc(drvdata->dev, sizeof(*drvdata->gpr),
> +					    GFP_KERNEL);
> +		if (!drvdata->gpr)
> +			return -ENOMEM;
> +	}
> +	if (test_bit(TPDM_DS_BC, drvdata->datasets)) {
> +		drvdata->bc = devm_kzalloc(drvdata->dev, sizeof(*drvdata->bc),
> +					   GFP_KERNEL);
> +		if (!drvdata->bc)
> +			return -ENOMEM;
> +	}
> +	if (test_bit(TPDM_DS_TC, drvdata->datasets)) {
> +		drvdata->tc = devm_kzalloc(drvdata->dev, sizeof(*drvdata->tc),
> +					   GFP_KERNEL);
> +		if (!drvdata->tc)
> +			return -ENOMEM;
> +	}
> +	if (test_bit(TPDM_DS_DSB, drvdata->datasets)) {
> +		drvdata->dsb = devm_kzalloc(drvdata->dev, sizeof(*drvdata->dsb),
> +					    GFP_KERNEL);
> +		if (!drvdata->dsb)
> +			return -ENOMEM;
> +	}
> +	if (test_bit(TPDM_DS_CMB, drvdata->datasets)) {
> +		drvdata->cmb = devm_kzalloc(drvdata->dev, sizeof(*drvdata->cmb),
> +					    GFP_KERNEL);
> +		if (!drvdata->cmb)
> +			return -ENOMEM;
> +	} else if (test_bit(TPDM_DS_MCMB, drvdata->datasets)) {
> +		drvdata->cmb = devm_kzalloc(drvdata->dev, sizeof(*drvdata->cmb),
> +					    GFP_KERNEL);
> +		if (!drvdata->cmb)
> +			return -ENOMEM;
> +		drvdata->cmb->mcmb = devm_kzalloc(drvdata->dev,
> +						  sizeof(*drvdata->cmb->mcmb),
> +						  GFP_KERNEL);
> +		if (!drvdata->cmb->mcmb)
> +			return -ENOMEM;

How can I understand what the above does when:

1) There isn't a single line of comments.
2) I don't know the HW.
3) I don't have access to the documentation.

> +	}
> +	return 0;
> +}
> +
> +static void tpdm_init_default_data(struct tpdm_drvdata *drvdata)
> +{
> +	if (test_bit(TPDM_DS_BC, drvdata->datasets))
> +		drvdata->bc->retrieval_mode = TPDM_MODE_ATB;
> +
> +	if (test_bit(TPDM_DS_TC, drvdata->datasets))
> +		drvdata->tc->retrieval_mode = TPDM_MODE_ATB;
> +
> +	if (test_bit(TPDM_DS_DSB, drvdata->datasets)) {
> +		drvdata->dsb->trig_ts = true;
> +		drvdata->dsb->trig_type = false;
> +	}
> +
> +	if (test_bit(TPDM_DS_CMB, drvdata->datasets) ||
> +	    test_bit(TPDM_DS_MCMB, drvdata->datasets))
> +		drvdata->cmb->trig_ts = true;
> +}
> +
> +static int tpdm_parse_of_data(struct tpdm_drvdata *drvdata)
> +{
> +	int i, ret;
> +	const char *tclk_name, *treg_name;
> +	struct device_node *node = drvdata->dev->of_node;
> +
> +	drvdata->clk_enable = of_property_read_bool(node, "qcom,clk-enable");
> +	drvdata->msr_fix_req = of_property_read_bool(node, "qcom,msr-fix-req");
> +	drvdata->cmb_msr_skip = of_property_read_bool(node,
> +					"qcom,cmb-msr-skip");
> +
> +	drvdata->nr_tclk = of_property_count_strings(node, "qcom,tpdm-clks");
> +	if (drvdata->nr_tclk > 0) {
> +		drvdata->tclk = devm_kzalloc(drvdata->dev, drvdata->nr_tclk *
> +					     sizeof(*drvdata->tclk),
> +					     GFP_KERNEL);
> +		if (!drvdata->tclk)
> +			return -ENOMEM;
> +
> +		for (i = 0; i < drvdata->nr_tclk; i++) {
> +			ret = of_property_read_string_index(node,
> +					    "qcom,tpdm-clks", i, &tclk_name);
> +			if (ret)
> +				return ret;
> +
> +			drvdata->tclk[i] = devm_clk_get(drvdata->dev,
> +							tclk_name);
> +			if (IS_ERR(drvdata->tclk[i]))
> +				return PTR_ERR(drvdata->tclk[i]);
> +		}
> +	}
> +
> +	drvdata->nr_treg = of_property_count_strings(node, "qcom,tpdm-regs");
> +	if (drvdata->nr_treg > 0) {
> +		drvdata->treg = devm_kzalloc(drvdata->dev, drvdata->nr_treg *
> +					     sizeof(*drvdata->treg),
> +					     GFP_KERNEL);
> +		if (!drvdata->treg)
> +			return -ENOMEM;
> +
> +		for (i = 0; i < drvdata->nr_treg; i++) {
> +			ret = of_property_read_string_index(node,
> +					    "qcom,tpdm-regs", i, &treg_name);
> +			if (ret)
> +				return ret;
> +
> +			drvdata->treg[i] = devm_regulator_get(drvdata->dev,
> +							treg_name);
> +			if (IS_ERR(drvdata->treg[i]))
> +				return PTR_ERR(drvdata->treg[i]);
> +		}
> +	}

_None_ of the above are defined in the yaml file and/or part of the example that
is shown there.  Moreover they don't appear in patch 10/10 where TPDM and TPDA are
supposed to be introduced.  I will comment on patch 10/10 when I'm done with
this one.

> +
> +	return 0;
> +}
> +
> +static int tpdm_probe(struct amba_device *adev, const struct amba_id *id)
> +{
> +	int ret, i;
> +	uint32_t pidr, devid;
> +	struct device *dev = &adev->dev;
> +	struct coresight_platform_data *pdata;
> +	struct tpdm_drvdata *drvdata;
> +	struct coresight_desc desc = { 0 };
> +	static int traceid = TPDM_TRACE_ID_START;
> +	uint32_t version;
> +
> +	desc.name = coresight_alloc_device_name(&tpdm_devs, dev);
> +	if (!desc.name)
> +		return -ENOMEM;
> +	pdata = coresight_get_platform_data(dev);
> +	if (IS_ERR(pdata))
> +		return PTR_ERR(pdata);
> +	adev->dev.platform_data = pdata;
> +
> +	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
> +	if (!drvdata)
> +		return -ENOMEM;
> +	drvdata->dev = &adev->dev;
> +	dev_set_drvdata(dev, drvdata);
> +
> +	drvdata->base = devm_ioremap_resource(dev, &adev->res);
> +	if (!drvdata->base)
> +		return -ENOMEM;
> +
> +	mutex_init(&drvdata->lock);
> +
> +	ret = tpdm_parse_of_data(drvdata);
> +	if (ret) {
> +		dev_err(drvdata->dev, "TPDM parse of data fail\n");
> +		return -EINVAL;
> +	}
> +
> +	desc.type = CORESIGHT_DEV_TYPE_SOURCE;
> +	desc.subtype.source_subtype = CORESIGHT_DEV_SUBTYPE_SOURCE_PROC;

Why is this of subtype CORESIGHT_DEV_SUBTYPE_SOURCE_PROC when TPDMs are not
associated with a CPU?  Here we should probably introduce something like
CORESIGHT_DEV_SUBTYPE_SOURCE_SYS

> +	desc.ops = &tpdm_cs_ops;
> +	desc.pdata = adev->dev.platform_data;
> +	desc.dev = &adev->dev;
> +	drvdata->csdev = coresight_register(&desc);
> +	if (IS_ERR(drvdata->csdev))
> +		return PTR_ERR(drvdata->csdev);
> +
> +	version = tpdm_readl(drvdata, CORESIGHT_PERIPHIDR2);
> +	drvdata->version = BMVAL(version, 4, 7);
> +

What is MSR support?  This should be documented.  Looking more closely at this
patch, not a single line of documentation is provided.  If you look at other
drivers, you will find things to be quite different.  The coresight subsystem
has become very complex and documentation helps us, and anyone trying to
contribute, understand what the code does.

> +	if (drvdata->version)
> +		drvdata->msr_support = true;
> +
> +	pidr = tpdm_readl(drvdata, CORESIGHT_PERIPHIDR0);
> +	for (i = 0; i < TPDM_DATASETS; i++) {
> +		if (pidr & BIT(i)) {
> +			__set_bit(i, drvdata->datasets);
> +			__set_bit(i, drvdata->enable_ds);
> +		}
> +	}
> +
> +	ret = tpdm_datasets_alloc(drvdata);
> +	if (ret) {
> +		coresight_unregister(drvdata->csdev);
> +		return ret;
> +	}
> +
> +	tpdm_init_default_data(drvdata);
> +
> +	devid = tpdm_readl(drvdata, CORESIGHT_DEVID);
> +	drvdata->tc_trig_type = BMVAL(devid, 27, 28);
> +	drvdata->bc_trig_type = BMVAL(devid, 25, 26);
> +	drvdata->bc_gang_type = BMVAL(devid, 23, 24);
> +	drvdata->bc_counters_avail = BMVAL(devid, 6, 10) + 1;
> +	drvdata->tc_counters_avail = BMVAL(devid, 4, 5) + 1;

Shouldn't this be part of tpdm_init_default_data()?

> +
> +	drvdata->traceid = traceid++;

For this to work a new function needs to be introduced in coresight-pmu.h.
Something like:

static inline int coresight_get_system_trace_id(int id)
{
        /* Start system IDs above the highest per CPU trace ID. */
        return coresigth_get_trace_id(cpumask_last(cpu_possible_mask) + 1);
}

> +
> +	dev_dbg(drvdata->dev, "TPDM initialized\n");

Please remove this.

> +
> +	if (boot_enable)
> +		coresight_enable(drvdata->csdev);
> +
> +	pm_runtime_put(&adev->dev);
> +
> +	return 0;
> +}
> +
> +static struct amba_id tpdm_ids[] = {
> +	{
> +		.id     = 0x001f0e00,
> +		.mask   = 0x00ffff00,

Any way we can use CS_AMBA_ID() here?

> +		.data	= "TPDM",

What is .data used for?

> +	},
> +	{ 0, 0},
> +};
> +
> +static struct amba_driver tpdm_driver = {
> +	.drv = {
> +		.name   = "coresight-tpdm",
> +		.owner	= THIS_MODULE,
> +		.suppress_bind_attrs = true,
> +	},
> +	.probe          = tpdm_probe,
> +	.id_table	= tpdm_ids,
> +};
> +
> +module_amba_driver(tpdm_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("Trace, Profiling & Diagnostic Monitor driver");
> -- 
> 2.17.1
>