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[23.128.96.18]) by mx.google.com with ESMTP id q10si12098135ilu.60.2021.07.04.13.26.17; Sun, 04 Jul 2021 13:26:29 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229743AbhGDU1U (ORCPT + 99 others); Sun, 4 Jul 2021 16:27:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:36006 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229649AbhGDU1U (ORCPT ); Sun, 4 Jul 2021 16:27:20 -0400 Received: from jic23-huawei (cpc108967-cmbg20-2-0-cust86.5-4.cable.virginm.net [81.101.6.87]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4E44B6115C; Sun, 4 Jul 2021 20:24:40 +0000 (UTC) Date: Sun, 4 Jul 2021 21:27:04 +0100 From: Jonathan Cameron To: Dipen Patel Cc: , , , , , , , , , , Subject: Re: [RFC 03/11] hte: Add tegra194 HTE kernel provider Message-ID: <20210704212704.26f5653b@jic23-huawei> In-Reply-To: <20210625235532.19575-4-dipenp@nvidia.com> References: <20210625235532.19575-1-dipenp@nvidia.com> <20210625235532.19575-4-dipenp@nvidia.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 25 Jun 2021 16:55:24 -0700 Dipen Patel wrote: > Tegra194 device has multiple HTE instances also known as GTE > (Generic hardware Timestamping Engine) which can timestamp subset of > SoC lines/signals. This provider driver focuses on IRQ and GPIO lines > and exposes timestamping ability on those lines to the consumers > through HTE subsystem. > > Also, with this patch, added: > - documentation about this provider and its capabilities at > Documentation/hte. > - Compilation support in Makefile and Kconfig > > Signed-off-by: Dipen Patel A few comments inline, J > --- > Documentation/hte/index.rst | 21 ++ > Documentation/hte/tegra194-hte.rst | 65 ++++ > Documentation/index.rst | 1 + > drivers/hte/Kconfig | 12 + > drivers/hte/Makefile | 1 + > drivers/hte/hte-tegra194.c | 554 +++++++++++++++++++++++++++++ > 6 files changed, 654 insertions(+) > create mode 100644 Documentation/hte/index.rst > create mode 100644 Documentation/hte/tegra194-hte.rst > create mode 100644 drivers/hte/hte-tegra194.c > > diff --git a/Documentation/hte/index.rst b/Documentation/hte/index.rst > new file mode 100644 > index 000000000000..f311ebec6b47 > --- /dev/null > +++ b/Documentation/hte/index.rst > @@ -0,0 +1,21 @@ > +.. SPDX-License-Identifier: GPL-2.0 > + > +============================================ > +The Linux Hardware Timestamping Engine (HTE) > +============================================ > + > +The HTE Subsystem > +================= > + > +.. toctree:: > + :maxdepth: 1 > + > + hte > + > +HTE Tegra Provider > +================== > + > +.. toctree:: > + :maxdepth: 1 > + > + tegra194-hte > \ No newline at end of file > diff --git a/Documentation/hte/tegra194-hte.rst b/Documentation/hte/tegra194-hte.rst > new file mode 100644 > index 000000000000..c23eaafcf080 > --- /dev/null > +++ b/Documentation/hte/tegra194-hte.rst > @@ -0,0 +1,65 @@ > +HTE Kernel provider driver > +========================== > + > +Description > +----------- > +The Nvidia tegra194 chip has many hardware timestamping engine (HTE) instances > +known as generic timestamping engine (GTE). This provider driver implements > +two GTE instances 1) GPIO GTE and 2) IRQ GTE. The both GTEs instances get the > +timestamp from the system counter TSC which has 31.25MHz clock rate, and the > +driver converts clock tick rate to nano seconds before storing it as timestamp > +value. > + > +GPIO GTE > +-------- > + > +This GTE instance help timestamps GPIO in real time, for that to happen GPIO > +needs to be configured as input and IRQ needs to ba enabled as well. The only > +always on (AON) gpio controller instance supports timestamping GPIOs in > +realtime and it has 39 GPIO lines. There is also a dependency on AON GPIO > +controller as it requires very specific bits to be set in GPIO config register. > +It in a way creates cyclic dependency between GTE and GPIO controller. The GTE > +GPIO functionality is accessed from the GPIOLIB. It can support both the in > +kernel and userspace consumers. In the later case, requests go through GPIOLIB > +CDEV framework. The below APIs are added in GPIOLIB framework to access HTE > +subsystem and GPIO GTE for in kernel consumers. > + > +.. c:function:: int gpiod_hw_timestamp_control( struct gpio_desc *desc, bool enable ) > + > + To enable HTE on given GPIO line. > + > +.. c:function:: u64 gpiod_get_hw_timestamp( struct gpio_desc *desc, bool block ) > + > + To retrieve hardwre timestamp in nano seconds. > + > +.. c:function:: bool gpiod_is_hw_timestamp_enabled( const struct gpio_desc *desc ) > + > + To query if HTE is enabled on the given GPIO. > + > +There is hte-tegra194-gpio-test.c, located in ``drivers/hte/`` directory, test > +driver which demonstrates above APIs for the Jetson AGX platform. For userspace > +consumers, GPIO_V2_LINE_FLAG_EVENT_CLOCK_HARDWARE flag must be specifed during > +IOCTL calls, refer ``tools/gpio/gpio-event-mon.c``, which returns the timestamp > +in nano second. > + > +IRQ GTE > +-------- > + > +This GTE instance helps timestamp LIC IRQ lines in real time. There are 352 IRQ > +lines which this instance can help timestamp realtime. The hte devicetree > +binding described at ``Documentation/devicetree/bindings/hte/`` gives out > +example how consumer can request IRQ line, since it is one to one mapping, > +consumers can simply specify IRQ number that they are interested in. There is > +no userspace consumer support for this GTE instance. The sample test code > +hte-tegra194-irq-test.c, located in ``drivers/hte/`` directory, > +demonstrates how to use IRQ GTE instance. The below is sample device tree > +snippet code for the test driver:: > + > + tegra_hte_irq_test { > + compatible = "nvidia,tegra194-hte-irq-test"; > + htes = <&tegra_hte_lic 0x19>; > + hte-names = "hte-lic"; > + }; > + > +The source code of the driver both IRQ and GPIO GTE is locate at > +``drivers/hte/hte-tegra194.c``. > \ No newline at end of file > diff --git a/Documentation/index.rst b/Documentation/index.rst > index 1b13c2445e87..b41118577fe6 100644 > --- a/Documentation/index.rst > +++ b/Documentation/index.rst > @@ -138,6 +138,7 @@ needed). > misc-devices/index > scheduler/index > mhi/index > + hte/index > > Architecture-agnostic documentation > ----------------------------------- > diff --git a/drivers/hte/Kconfig b/drivers/hte/Kconfig > index 394e112f7dfb..f7b01fcc7190 100644 > --- a/drivers/hte/Kconfig > +++ b/drivers/hte/Kconfig > @@ -20,3 +20,15 @@ menuconfig HTE > > If unsure, say no. > > +if HTE > + > +config HTE_TEGRA194 > + tristate "NVIDIA Tegra194 HTE Support" > + depends on ARCH_TEGRA_194_SOC > + help > + Enable this option for integrated hardware timestamping engine also > + known as generic timestamping engine (GTE) support on NVIDIA Tegra194 > + systems-on-chip. The driver supports 352 LIC IRQs and 39 AON GPIOs > + lines for timestamping in realtime. > + > +endif > diff --git a/drivers/hte/Makefile b/drivers/hte/Makefile > index 9899dbe516f7..52f978cfc913 100644 > --- a/drivers/hte/Makefile > +++ b/drivers/hte/Makefile > @@ -1 +1,2 @@ > obj-$(CONFIG_HTE) += hte.o > +obj-$(CONFIG_HTE_TEGRA194) += hte-tegra194.o > \ No newline at end of file fix that > diff --git a/drivers/hte/hte-tegra194.c b/drivers/hte/hte-tegra194.c > new file mode 100644 > index 000000000000..8ad10efd3641 > --- /dev/null > +++ b/drivers/hte/hte-tegra194.c > @@ -0,0 +1,554 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (c) 2021 NVIDIA Corporation > + * > + * Author: Dipen Patel > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#define HTE_SUSPEND 0 > + > +/* HTE source clock TSC is 31.25MHz */ > +#define HTE_TS_CLK_RATE_HZ 31250000ULL > +#define HTE_CLK_RATE_NS 32 > +#define HTE_TS_NS_SHIFT __builtin_ctz(HTE_CLK_RATE_NS) > + > +#define NV_AON_SLICE_INVALID -1 > + > +/* AON HTE line map For slice 1 */ > +#define NV_AON_HTE_SLICE1_IRQ_GPIO_28 12 > +#define NV_AON_HTE_SLICE1_IRQ_GPIO_29 13 > + > +/* AON HTE line map For slice 2 */ > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_0 0 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_1 1 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_2 2 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_3 3 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_4 4 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_5 5 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_6 6 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_7 7 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_8 8 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_9 9 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_10 10 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_11 11 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_12 12 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_13 13 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_14 14 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_15 15 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_16 16 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_17 17 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_18 18 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_19 19 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_20 20 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_21 21 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_22 22 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_23 23 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_24 24 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_25 25 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_26 26 > +#define NV_AON_HTE_SLICE2_IRQ_GPIO_27 27 > + > +/* AON GPIO port AA pins */ > +#define NV_AON_GPIO_PORT_AA_0 0 > +#define NV_AON_GPIO_PORT_AA_1 1 > +#define NV_AON_GPIO_PORT_AA_2 2 > +#define NV_AON_GPIO_PORT_AA_3 3 > +#define NV_AON_GPIO_PORT_AA_4 4 > +#define NV_AON_GPIO_PORT_AA_5 5 > +#define NV_AON_GPIO_PORT_AA_6 6 > +#define NV_AON_GPIO_PORT_AA_7 7 > + > +/* AON GPIO port BB pins */ > +#define NV_AON_GPIO_PORT_BB_0 8 > +#define NV_AON_GPIO_PORT_BB_1 9 > +#define NV_AON_GPIO_PORT_BB_2 10 > +#define NV_AON_GPIO_PORT_BB_3 11 > + > +/* AON GPIO port CC pins */ > +#define NV_AON_GPIO_PORT_CC_0 16 > +#define NV_AON_GPIO_PORT_CC_1 17 > +#define NV_AON_GPIO_PORT_CC_2 18 > +#define NV_AON_GPIO_PORT_CC_3 19 > +#define NV_AON_GPIO_PORT_CC_4 20 > +#define NV_AON_GPIO_PORT_CC_5 21 > +#define NV_AON_GPIO_PORT_CC_6 22 > +#define NV_AON_GPIO_PORT_CC_7 23 > + > +/* AON GPIO port DD pins */ > +#define NV_AON_GPIO_PORT_DD_0 24 > +#define NV_AON_GPIO_PORT_DD_1 25 > +#define NV_AON_GPIO_PORT_DD_2 26 > + > +/* AON GPIO port EE pins */ > +#define NV_AON_GPIO_PORT_EE_0 32 > +#define NV_AON_GPIO_PORT_EE_1 33 > +#define NV_AON_GPIO_PORT_EE_2 34 > +#define NV_AON_GPIO_PORT_EE_3 35 > +#define NV_AON_GPIO_PORT_EE_4 36 > +#define NV_AON_GPIO_PORT_EE_5 37 > +#define NV_AON_GPIO_PORT_EE_6 38 > + > + > +#define HTE_TECTRL 0x0 > +#define HTE_TETSCH 0x4 > +#define HTE_TETSCL 0x8 > +#define HTE_TESRC 0xC > +#define HTE_TECCV 0x10 > +#define HTE_TEPCV 0x14 > +#define HTE_TECMD 0x1C > +#define HTE_TESTATUS 0x20 > +#define HTE_SLICE0_TETEN 0x40 > +#define HTE_SLICE1_TETEN 0x60 > + > +#define HTE_SLICE_SIZE (HTE_SLICE1_TETEN - HTE_SLICE0_TETEN) > + > +#define HTE_TECTRL_ENABLE_ENABLE 0x1 > + > +#define HTE_TECTRL_OCCU_SHIFT 0x8 > +#define HTE_TECTRL_INTR_SHIFT 0x1 > +#define HTE_TECTRL_INTR_ENABLE 0x1 > + > +#define HTE_TESRC_SLICE_SHIFT 16 > +#define HTE_TESRC_SLICE_DEFAULT_MASK 0xFF > + > +#define HTE_TECMD_CMD_POP 0x1 > + > +#define HTE_TESTATUS_OCCUPANCY_SHIFT 8 > +#define HTE_TESTATUS_OCCUPANCY_MASK 0xFF > + > +struct hte_slices { > + u32 r_val; > + unsigned long flags; > + /* to prevent lines mapped to same slice updating its register */ > + spinlock_t s_lock; > +}; > + > +struct tegra_hte_line_mapped { > + int slice; > + u32 bit_index; > +}; > + > +struct tegra_hte_line_table { > + int map_sz; > + const struct tegra_hte_line_mapped *map; > +}; > + > +struct tegra_hte_soc { > + int hte_irq; > + u32 itr_thrshld; > + u32 conf_rval; > + struct hte_slices *sl; > + const struct tegra_hte_line_table *line_map; > + struct hte_chip *chip; > + void __iomem *regs; > +}; > + > +static const struct tegra_hte_line_mapped tegra194_aon_gpio_map[] = { > + /* gpio, slice, bit_index */ > + [NV_AON_GPIO_PORT_AA_0] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_11}, > + [NV_AON_GPIO_PORT_AA_1] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_10}, > + [NV_AON_GPIO_PORT_AA_2] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_9}, > + [NV_AON_GPIO_PORT_AA_3] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_8}, > + [NV_AON_GPIO_PORT_AA_4] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_7}, > + [NV_AON_GPIO_PORT_AA_5] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_6}, > + [NV_AON_GPIO_PORT_AA_6] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_5}, > + [NV_AON_GPIO_PORT_AA_7] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_4}, > + [NV_AON_GPIO_PORT_BB_0] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_3}, > + [NV_AON_GPIO_PORT_BB_1] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_2}, > + [NV_AON_GPIO_PORT_BB_2] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_1}, > + [NV_AON_GPIO_PORT_BB_3] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_0}, > + [12] = {NV_AON_SLICE_INVALID, 0}, > + [13] = {NV_AON_SLICE_INVALID, 0}, > + [14] = {NV_AON_SLICE_INVALID, 0}, > + [15] = {NV_AON_SLICE_INVALID, 0}, > + [NV_AON_GPIO_PORT_CC_0] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_22}, > + [NV_AON_GPIO_PORT_CC_1] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_21}, > + [NV_AON_GPIO_PORT_CC_2] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_20}, > + [NV_AON_GPIO_PORT_CC_3] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_19}, > + [NV_AON_GPIO_PORT_CC_4] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_18}, > + [NV_AON_GPIO_PORT_CC_5] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_17}, > + [NV_AON_GPIO_PORT_CC_6] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_16}, > + [NV_AON_GPIO_PORT_CC_7] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_15}, > + [NV_AON_GPIO_PORT_DD_0] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_14}, > + [NV_AON_GPIO_PORT_DD_1] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_13}, > + [NV_AON_GPIO_PORT_DD_2] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_12}, > + [27] = {NV_AON_SLICE_INVALID, 0}, > + [28] = {NV_AON_SLICE_INVALID, 0}, > + [29] = {NV_AON_SLICE_INVALID, 0}, > + [30] = {NV_AON_SLICE_INVALID, 0}, > + [31] = {NV_AON_SLICE_INVALID, 0}, > + [NV_AON_GPIO_PORT_EE_0] = {1, NV_AON_HTE_SLICE1_IRQ_GPIO_29}, > + [NV_AON_GPIO_PORT_EE_1] = {1, NV_AON_HTE_SLICE1_IRQ_GPIO_28}, > + [NV_AON_GPIO_PORT_EE_2] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_27}, > + [NV_AON_GPIO_PORT_EE_3] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_26}, > + [NV_AON_GPIO_PORT_EE_4] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_25}, > + [NV_AON_GPIO_PORT_EE_5] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_24}, > + [NV_AON_GPIO_PORT_EE_6] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_23}, > +}; > + > +static const struct tegra_hte_line_table aon_hte_map = { > + .map_sz = ARRAY_SIZE(tegra194_aon_gpio_map), > + .map = tegra194_aon_gpio_map, > +}; > + > +static inline u32 tegra_hte_readl(struct tegra_hte_soc *hte, u32 reg) > +{ > + return readl(hte->regs + reg); > +} > + > +static inline void tegra_hte_writel(struct tegra_hte_soc *hte, u32 reg, > + u32 val) > +{ > + writel(val, hte->regs + reg); > +} > + > +static inline int tegra_hte_map_to_line_id(u32 eid, struct tegra_hte_soc *gs, > + u32 *mapped) > +{ > + const struct tegra_hte_line_mapped *m; > + > + if (gs->line_map) { > + m = gs->line_map->map; > + if (eid > gs->line_map->map_sz) > + return -EINVAL; > + if (m[eid].slice == NV_AON_SLICE_INVALID) > + return -EINVAL; > + > + *mapped = (m[eid].slice << 5) + m[eid].bit_index; > + } else { > + *mapped = eid; > + } > + > + return 0; > +} > + > +static int tegra_hte_line_xlate(struct hte_chip *gc, > + const struct of_phandle_args *args, > + struct hte_ts_desc *desc, u32 *xlated_id) > +{ > + int ret = 0; > + > + if (!gc || !desc || !xlated_id) > + return -EINVAL; > + > + if (args) { > + if (gc->of_hte_n_cells < 1) > + return -EINVAL; > + > + if (args->args_count != gc->of_hte_n_cells) > + return -EINVAL; > + > + desc->con_id = args->args[0]; > + } > + > + ret = tegra_hte_map_to_line_id(desc->con_id, gc->data, > + xlated_id); > + if (ret < 0) { > + dev_dbg(gc->dev, "con_id:%u mapping failed\n", > + desc->con_id); > + return ret; > + } > + > + if (*xlated_id > gc->nlines) > + return -EINVAL; > + > + dev_dbg(gc->dev, "requested id:%u, xlated id:%u\n", > + desc->con_id, *xlated_id); > + > + return 0; > +} > + > +static int tegra_hte_en_dis_common(struct hte_chip *chip, u32 line_id, bool en) > +{ > + u32 slice, sl_bit_shift, line_bit, val, reg; > + struct tegra_hte_soc *gs; > + > + sl_bit_shift = __builtin_ctz(HTE_SLICE_SIZE); > + > + if (!chip) > + return -EINVAL; > + > + gs = (struct tegra_hte_soc *)chip->data; > + > + if (line_id > chip->nlines) { > + dev_err(chip->dev, > + "line id: %u is not supported by this controller\n", > + line_id); > + return -EINVAL; > + } > + > + slice = line_id >> sl_bit_shift; > + line_bit = line_id & (HTE_SLICE_SIZE - 1); > + reg = (slice << sl_bit_shift) + HTE_SLICE0_TETEN; > + > + spin_lock(&gs->sl[slice].s_lock); > + > + if (test_bit(HTE_SUSPEND, &gs->sl[slice].flags)) { > + spin_unlock(&gs->sl[slice].s_lock); > + dev_dbg(chip->dev, "device suspended"); > + return -EBUSY; > + } > + > + val = tegra_hte_readl(gs, reg); > + if (en) > + val = val | (1 << line_bit); > + else > + val = val & (~(1 << line_bit)); > + tegra_hte_writel(gs, reg, val); > + > + spin_unlock(&gs->sl[slice].s_lock); > + > + dev_dbg(chip->dev, "line: %u, slice %u, line_bit %u, reg:0x%x\n", > + line_id, slice, line_bit, reg); > + > + return 0; > +} > + > +static int tegra_hte_request(struct hte_chip *chip, u32 line_id) > +{ > + return tegra_hte_en_dis_common(chip, line_id, true); > +} > + > +static int tegra_hte_release(struct hte_chip *chip, u32 line_id) > +{ > + return tegra_hte_en_dis_common(chip, line_id, false); > +} > + > +static int tegra_hte_clk_src_info(struct hte_chip *chip, > + struct hte_clk_info *ci) > +{ > + (void)chip; > + > + ci->hz = HTE_TS_CLK_RATE_HZ; > + ci->type = CLOCK_MONOTONIC; > + > + return 0; > +} > + > +static void tegra_hte_read_fifo(struct tegra_hte_soc *gs) > +{ > + u32 tsh, tsl, src, pv, cv, acv, slice, bit_index, line_id; > + u64 tsc; > + int dir; > + struct hte_ts_data el; > + > + while ((tegra_hte_readl(gs, HTE_TESTATUS) >> > + HTE_TESTATUS_OCCUPANCY_SHIFT) & > + HTE_TESTATUS_OCCUPANCY_MASK) { > + tsh = tegra_hte_readl(gs, HTE_TETSCH); > + tsl = tegra_hte_readl(gs, HTE_TETSCL); > + tsc = (((u64)tsh << 32) | tsl); > + > + src = tegra_hte_readl(gs, HTE_TESRC); > + slice = (src >> HTE_TESRC_SLICE_SHIFT) & > + HTE_TESRC_SLICE_DEFAULT_MASK; > + > + pv = tegra_hte_readl(gs, HTE_TEPCV); > + cv = tegra_hte_readl(gs, HTE_TECCV); > + acv = pv ^ cv; > + while (acv) { > + bit_index = __builtin_ctz(acv); > + if ((pv >> bit_index) & BIT(0)) > + dir = HTE_EVENT_RISING_EDGE; > + else > + dir = HTE_EVENT_FALLING_EDGE; > + > + line_id = bit_index + (slice << 5); > + el.dir = dir; > + el.tsc = tsc << HTE_TS_NS_SHIFT; > + hte_push_ts_ns_atomic(gs->chip, line_id, &el, > + sizeof(el)); > + acv &= ~BIT(bit_index); > + } > + tegra_hte_writel(gs, HTE_TECMD, HTE_TECMD_CMD_POP); > + } > +} > + > +static irqreturn_t tegra_hte_isr(int irq, void *dev_id) > +{ > + struct tegra_hte_soc *gs = dev_id; > + > + tegra_hte_read_fifo(gs); > + > + return IRQ_HANDLED; > +} > + > +static const struct of_device_id tegra_hte_of_match[] = { > + { .compatible = "nvidia,tegra194-gte-lic"}, > + { .compatible = "nvidia,tegra194-gte-aon", .data = &aon_hte_map}, > + { } > +}; > +MODULE_DEVICE_TABLE(of, tegra_hte_of_match); > + > +static const struct hte_ops g_ops = { > + .request = tegra_hte_request, > + .release = tegra_hte_release, > + .enable = tegra_hte_request, > + .disable = tegra_hte_release, > + .get_clk_src_info = tegra_hte_clk_src_info, > +}; > + > +static int tegra_hte_probe(struct platform_device *pdev) > +{ > + int ret; > + u32 i, slices, val = 0; > + struct device *dev; > + struct tegra_hte_soc *hte_dev; > + struct hte_chip *gc; > + > + dev = &pdev->dev; > + > + hte_dev = devm_kzalloc(dev, sizeof(*hte_dev), GFP_KERNEL); > + if (!hte_dev) > + return -ENOMEM; > + > + gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL); > + if (!gc) > + return -ENOMEM; > + > + dev_set_drvdata(&pdev->dev, hte_dev); > + hte_dev->line_map = of_device_get_match_data(&pdev->dev); > + > + hte_dev->regs = devm_platform_ioremap_resource(pdev, 0); > + if (IS_ERR(hte_dev->regs)) > + return PTR_ERR(hte_dev->regs); > + > + ret = of_property_read_u32(dev->of_node, "int-threshold", > + &hte_dev->itr_thrshld); > + if (ret != 0) > + hte_dev->itr_thrshld = 1; > + > + ret = of_property_read_u32(dev->of_node, "slices", &slices); > + if (ret != 0) { > + dev_err(dev, "Could not read slices\n"); > + return -EINVAL; > + } > + > + hte_dev->sl = devm_kzalloc(dev, sizeof(struct hte_slices) * slices, Preference for sizeof(*hte_dev->sl) as it saves me checking the size is correct for the type. > + GFP_KERNEL); > + if (!hte_dev->sl) > + return -ENOMEM; > + > + ret = platform_get_irq(pdev, 0); > + if (ret < 0) { > + dev_err(dev, "get irq failed.\n"); dev_err_probe() probably so you don't print the message if deferred probing is going on. > + return ret; > + } > + hte_dev->hte_irq = ret; > + ret = devm_request_irq(dev, hte_dev->hte_irq, tegra_hte_isr, 0, > + dev_name(dev), hte_dev); > + if (ret < 0) { > + dev_err(dev, "request irq failed.\n"); > + return ret; > + } > + > + gc->nlines = slices << 5; > + gc->ops = &g_ops; > + gc->dev = dev; > + hte_dev->chip = gc; > + gc->data = (void *)hte_dev; Don't case to void * - cast to the actual type if necessary. If it is a void * then most likely it shouldn't be if we always put something in particular it in it. > + gc->xlate = tegra_hte_line_xlate; > + gc->of_hte_n_cells = 1; > + > + ret = hte_register_chip(hte_dev->chip); > + No blank line before error handler. Under the circumstances is that not fatal? > + if (ret) > + dev_err(gc->dev, "hte chip register failed"); > + > + for (i = 0; i < slices; i++) { > + hte_dev->sl[i].flags = 0; > + spin_lock_init(&hte_dev->sl[i].s_lock); > + } > + > + val = HTE_TECTRL_ENABLE_ENABLE | > + (HTE_TECTRL_INTR_ENABLE << HTE_TECTRL_INTR_SHIFT) | > + (hte_dev->itr_thrshld << HTE_TECTRL_OCCU_SHIFT); > + tegra_hte_writel(hte_dev, HTE_TECTRL, val); You could use a devm_add_action_or_reset() to deal with unwinding this plus add a devm_hte_register_chip() and then you can get rid of remove entirely which is always nice. > + > + dev_dbg(gc->dev, "lines: %d, slices:%d", gc->nlines, slices); > + return 0; > +} > + > +static int tegra_hte_remove(struct platform_device *pdev) > +{ > + struct tegra_hte_soc *gs = dev_get_drvdata(&pdev->dev); > + > + tegra_hte_writel(gs, HTE_TECTRL, 0); > + > + return hte_unregister_chip(gs->chip); > +} > + > +#ifdef CONFIG_PM_SLEEP Personally I prefer the approach of marking PM functions __maybe_unused and dropping the ifdef protections. There have been a lot of subtle issues in the build system in the past around those and it's much easier to just let the compiler drop them if they are unused. > +static int tegra_hte_resume_early(struct device *dev) > +{ > + u32 i; > + struct tegra_hte_soc *gs = dev_get_drvdata(dev); > + u32 slices = gs->chip->nlines >> 5; Whilst it's the same thing, I'd prefer a divide there by however lines there are in a slice. > + u32 sl_bit_shift = __builtin_ctz(HTE_SLICE_SIZE); > + > + tegra_hte_writel(gs, HTE_TECTRL, gs->conf_rval); > + > + for (i = 0; i < slices; i++) { > + spin_lock(&gs->sl[i].s_lock); > + tegra_hte_writel(gs, > + ((i << sl_bit_shift) + HTE_SLICE0_TETEN), > + gs->sl[i].r_val); > + clear_bit(HTE_SUSPEND, &gs->sl[i].flags); > + spin_unlock(&gs->sl[i].s_lock); > + } > + > + return 0; > +} > + > +static int tegra_hte_suspend_late(struct device *dev) > +{ > + u32 i; > + struct tegra_hte_soc *gs = dev_get_drvdata(dev); > + u32 slices = gs->chip->nlines >> 5; > + u32 sl_bit_shift = __builtin_ctz(HTE_SLICE_SIZE); > + > + gs->conf_rval = tegra_hte_readl(gs, HTE_TECTRL); > + for (i = 0; i < slices; i++) { > + spin_lock(&gs->sl[i].s_lock); > + gs->sl[i].r_val = tegra_hte_readl(gs, > + ((i << sl_bit_shift) + HTE_SLICE0_TETEN)); > + set_bit(HTE_SUSPEND, &gs->sl[i].flags); > + spin_unlock(&gs->sl[i].s_lock); > + } > + > + return 0; > +} > +#endif > + > +static const struct dev_pm_ops tegra_hte_pm = { > + SET_LATE_SYSTEM_SLEEP_PM_OPS(tegra_hte_suspend_late, > + tegra_hte_resume_early) > +}; > + > +static struct platform_driver tegra_hte_driver = { > + .probe = tegra_hte_probe, > + .remove = tegra_hte_remove, > + .driver = { > + .name = "tegra_hte", > + .pm = &tegra_hte_pm, > + .of_match_table = tegra_hte_of_match, > + }, > +}; > + > +module_platform_driver(tegra_hte_driver); > + > +MODULE_AUTHOR("Dipen Patel "); > +MODULE_DESCRIPTION("NVIDIA Tegra HTE (Hardware Timestamping Engine) driver"); > +MODULE_LICENSE("GPL v2");