From patchwork Thu Feb 17 11:30:03 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Srba X-Patchwork-Id: 543441 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 045E4C43219 for ; Thu, 17 Feb 2022 11:33:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234361AbiBQLdN (ORCPT ); Thu, 17 Feb 2022 06:33:13 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:56958 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239208AbiBQLdI (ORCPT ); Thu, 17 Feb 2022 06:33:08 -0500 Received: from mxd2.seznam.cz (mxd2.seznam.cz [IPv6:2a02:598:2::210]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DD240170D50; Thu, 17 Feb 2022 03:32:50 -0800 (PST) Received: from email.seznam.cz by email-smtpc29a.ng.seznam.cz (email-smtpc29a.ng.seznam.cz [10.23.18.42]) id 7cd3f31827dda7717d7a3f46; Thu, 17 Feb 2022 12:32:40 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=seznam.cz; s=beta; t=1645097560; bh=VD3cEEOkBw2sc1mcTfjsONakIM1gFm8vpwXLE+M1a90=; h=Received:From:To:Cc:Subject:Date:Message-Id:X-Mailer:In-Reply-To: References:MIME-Version:Content-Transfer-Encoding:X-szn-frgn: X-szn-frgc; b=oAcbdyVDUlahrJ73wZ9aIMu/QtysMsC+hMGpzWjXYnfTCiZdC+3Qtt8jntqlSDvWu rlKTIZ9ptOvdM2t1iOwOri+rPK/mGgpOaKvSCi9Fg/5aF78Ku3NFWHk8J1/RdKsUmy DN7pS9tJDA78YFHoXVFUFNyTOjk/9KChOona9MFs= Received: from localhost.localdomain (ip-111-27.static.ccinternet.cz [147.161.27.111]) by email-relay20.ng.seznam.cz (Seznam SMTPD 1.3.136) with ESMTP; Thu, 17 Feb 2022 12:32:37 +0100 (CET) From: michael.srba@seznam.cz To: Andy Gross , Bjorn Andersson , Rob Herring , Stephen Boyd , Philipp Zabel Cc: Linus Walleij , Florian Fainelli , Arnd Bergmann , Greg Kroah-Hartman , Saravana Kannan , linux-arm-msm@vger.kernel.org, linux-clk@vger.kernel.org, devicetree@vger.kernel.org, Michael Srba Subject: [PATCH v6 4/5] drivers: bus: add driver for initializing the SSC bus on (some) qcom SoCs Date: Thu, 17 Feb 2022 12:30:03 +0100 Message-Id: <20220217113004.22757-4-michael.srba@seznam.cz> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220217113004.22757-1-michael.srba@seznam.cz> References: <20220217113004.22757-1-michael.srba@seznam.cz> MIME-Version: 1.0 X-szn-frgn: <4cb72399-da46-4d26-8f81-8242b25a2eda> X-szn-frgc: <0> Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org From: Michael Srba This patch adds bindings for the AHB bus which exposes the SCC block in the global address space. This bus (and the SSC block itself) is present on certain qcom SoCs. In typical configuration, this bus (as some of the clocks and registers that we need to manipulate) is not accessible to Linux, and the resources on this bus are indirectly accessed by communicating with a hexagon CPU core residing in the SSC block. In this configuration, the hypervisor is the one performing the bus initialization for the purposes of bringing the haxagon CPU core out of reset. However, it is possible to change the configuration, in which case this driver will initialize the bus. In combination with drivers for resources on the SSC bus, this driver can aid in debugging, and for example with a TLMM driver can be used to directly access SSC-dedicated GPIO pins, removing the need to commit to a particular usecase during hw design. Finally, until open firmware for the hexagon core is available, this approach allows for using sensors hooked up to SSC-dedicated GPIO pins on mainline Linux simply by utilizing the existing in-tree drivers for these sensors. Signed-off-by: Michael Srba --- CHANGES: - v2: none - v3: fix clang warning - v4: address the issues pointed out in the review - v5: none - v6: restore alphabetic ordering in Makefile against v5.17-rc4 --- drivers/bus/Kconfig | 6 + drivers/bus/Makefile | 1 + drivers/bus/qcom-ssc-block-bus.c | 383 +++++++++++++++++++++++++++++++ 3 files changed, 390 insertions(+) create mode 100644 drivers/bus/qcom-ssc-block-bus.c diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig index 3c68e174a113..9e29d1da9a61 100644 --- a/drivers/bus/Kconfig +++ b/drivers/bus/Kconfig @@ -152,6 +152,12 @@ config QCOM_EBI2 Interface 2, which can be used to connect things like NAND Flash, SRAM, ethernet adapters, FPGAs and LCD displays. +config QCOM_SSC_BLOCK_BUS + bool "Qualcomm SSC Block Bus Init Driver" + help + Say y here to enable support for initializing the bus that connects the SSC block's internal + bus to the cNoC on (some) qcom SoCs + config SUN50I_DE2_BUS bool "Allwinner A64 DE2 Bus Driver" default ARM64 diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile index 52c2f35a26a9..e6756e83a9c4 100644 --- a/drivers/bus/Makefile +++ b/drivers/bus/Makefile @@ -25,6 +25,7 @@ obj-$(CONFIG_OMAP_INTERCONNECT) += omap_l3_smx.o omap_l3_noc.o obj-$(CONFIG_OMAP_OCP2SCP) += omap-ocp2scp.o obj-$(CONFIG_QCOM_EBI2) += qcom-ebi2.o +obj-$(CONFIG_QCOM_SSC_BLOCK_BUS) += qcom-ssc-block-bus.o obj-$(CONFIG_SUN50I_DE2_BUS) += sun50i-de2.o obj-$(CONFIG_SUNXI_RSB) += sunxi-rsb.o obj-$(CONFIG_OF) += simple-pm-bus.o diff --git a/drivers/bus/qcom-ssc-block-bus.c b/drivers/bus/qcom-ssc-block-bus.c new file mode 100644 index 000000000000..e489f5614e90 --- /dev/null +++ b/drivers/bus/qcom-ssc-block-bus.c @@ -0,0 +1,383 @@ +// SPDX-License-Identifier: GPL-2.0-only +// Copyright (c) 2021, Michael Srba + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* AXI Halt Register Offsets */ +#define AXI_HALTREQ_REG 0x0 +#define AXI_HALTACK_REG 0x4 +#define AXI_IDLE_REG 0x8 + +static const char *const qcom_ssc_block_pd_names[] = { + "ssc_cx", + "ssc_mx" +}; + +struct qcom_ssc_block_bus_data { + int num_pds; + const char *const *pd_names; + struct device *pds[ARRAY_SIZE(qcom_ssc_block_pd_names)]; + char __iomem *reg_mpm_sscaon_config0; // MPM - msm power manager; AON - always-on + char __iomem *reg_mpm_sscaon_config1; // that's as much as we know about these + struct regmap *halt_map; + u32 ssc_axi_halt; + struct clk *xo_clk; + struct clk *aggre2_clk; + struct clk *gcc_im_sleep_clk; + struct clk *aggre2_north_clk; + struct clk *ssc_xo_clk; + struct clk *ssc_ahbs_clk; + struct reset_control *ssc_bcr; + struct reset_control *ssc_reset; +}; + +static void reg32_set_bits(char __iomem *reg, u32 value) +{ + u32 tmp = ioread32(reg); + + iowrite32(tmp | value, reg); +} + +static void reg32_clear_bits(char __iomem *reg, u32 value) +{ + u32 tmp = ioread32(reg); + + iowrite32(tmp & (~value), reg); +} + + +static int qcom_ssc_block_bus_init(struct device *dev) +{ + int ret; + + struct qcom_ssc_block_bus_data *data = dev_get_drvdata(dev); + + ret = clk_prepare_enable(data->xo_clk); + if (ret) { + dev_err(dev, "error enabling xo_clk: %d\n", ret); + goto err_xo_clk; + } + + ret = clk_prepare_enable(data->aggre2_clk); + if (ret) { + dev_err(dev, "error enabling aggre2_clk: %d\n", ret); + goto err_aggre2_clk; + } + + ret = clk_prepare_enable(data->gcc_im_sleep_clk); + if (ret) { + dev_err(dev, "error enabling gcc_im_sleep_clk: %d\n", ret); + goto err_gcc_im_sleep_clk; + } + + reg32_clear_bits(data->reg_mpm_sscaon_config0, BIT(4) | BIT(5)); + reg32_clear_bits(data->reg_mpm_sscaon_config1, BIT(31)); + + ret = clk_prepare_enable(data->aggre2_north_clk); + if (ret) { + dev_err(dev, "error enabling aggre2_north_clk: %d\n", ret); + goto err_aggre2_north_clk; + } + + ret = reset_control_deassert(data->ssc_reset); + if (ret) { + dev_err(dev, "error deasserting ssc_reset: %d\n", ret); + goto err_ssc_reset; + } + + ret = reset_control_deassert(data->ssc_bcr); + if (ret) { + dev_err(dev, "error deasserting ssc_bcr: %d\n", ret); + goto err_ssc_bcr; + } + + regmap_write(data->halt_map, data->ssc_axi_halt + AXI_HALTREQ_REG, 0); + + ret = clk_prepare_enable(data->ssc_xo_clk); + if (ret) { + dev_err(dev, "error deasserting ssc_xo_clk: %d\n", ret); + goto err_ssc_xo_clk; + } + + ret = clk_prepare_enable(data->ssc_ahbs_clk); + if (ret) { + dev_err(dev, "error deasserting ssc_ahbs_clk: %d\n", ret); + goto err_ssc_ahbs_clk; + } + + return 0; + +err_ssc_ahbs_clk: + clk_disable(data->ssc_xo_clk); + +err_ssc_xo_clk: + regmap_write(data->halt_map, data->ssc_axi_halt + AXI_HALTREQ_REG, 1); + + reset_control_assert(data->ssc_bcr); + +err_ssc_bcr: + reset_control_assert(data->ssc_reset); + +err_ssc_reset: + clk_disable(data->aggre2_north_clk); + +err_aggre2_north_clk: + reg32_set_bits(data->reg_mpm_sscaon_config0, BIT(4) | BIT(5)); + reg32_set_bits(data->reg_mpm_sscaon_config1, BIT(31)); + + clk_disable(data->gcc_im_sleep_clk); + +err_gcc_im_sleep_clk: + clk_disable(data->aggre2_clk); + +err_aggre2_clk: + clk_disable(data->xo_clk); + +err_xo_clk: + return ret; +} + +static void qcom_ssc_block_bus_deinit(struct device *dev) +{ + int ret; + + struct qcom_ssc_block_bus_data *data = dev_get_drvdata(dev); + + clk_disable(data->ssc_xo_clk); + clk_disable(data->ssc_ahbs_clk); + + ret = reset_control_assert(data->ssc_bcr); + if (ret) + dev_err(dev, "error asserting ssc_bcr: %d\n", ret); + + regmap_write(data->halt_map, data->ssc_axi_halt + AXI_HALTREQ_REG, 1); + + reg32_set_bits(data->reg_mpm_sscaon_config1, BIT(31)); + reg32_set_bits(data->reg_mpm_sscaon_config0, BIT(4) | BIT(5)); + + ret = reset_control_assert(data->ssc_reset); + if (ret) + dev_err(dev, "error asserting ssc_reset: %d\n", ret); + + clk_disable(data->gcc_im_sleep_clk); + + clk_disable(data->aggre2_north_clk); + + clk_disable(data->aggre2_clk); + clk_disable(data->xo_clk); +} + + +static int qcom_ssc_block_bus_pds_attach(struct device *dev, struct device **pds, + const char *const *pd_names, size_t num_pds) +{ + int ret; + int i; + + for (i = 0; i < num_pds; i++) { + pds[i] = dev_pm_domain_attach_by_name(dev, pd_names[i]); + if (IS_ERR_OR_NULL(pds[i])) { + ret = PTR_ERR(pds[i]) ? : -ENODATA; + goto unroll_attach; + } + } + + return num_pds; + +unroll_attach: + for (i--; i >= 0; i--) + dev_pm_domain_detach(pds[i], false); + + return ret; +}; + +static void qcom_ssc_block_bus_pds_detach(struct device *dev, struct device **pds, size_t num_pds) +{ + int i; + + for (i = 0; i < num_pds; i++) + dev_pm_domain_detach(pds[i], false); +} + +static int qcom_ssc_block_bus_pds_enable(struct device **pds, size_t num_pds) +{ + int ret; + int i; + + for (i = 0; i < num_pds; i++) { + dev_pm_genpd_set_performance_state(pds[i], INT_MAX); + ret = pm_runtime_get_sync(pds[i]); + if (ret < 0) + goto unroll_pd_votes; + } + + return 0; + +unroll_pd_votes: + for (i--; i >= 0; i--) { + dev_pm_genpd_set_performance_state(pds[i], 0); + pm_runtime_put(pds[i]); + } + + return ret; +}; + +static void qcom_ssc_block_bus_pds_disable(struct device **pds, size_t num_pds) +{ + int i; + + for (i = 0; i < num_pds; i++) { + dev_pm_genpd_set_performance_state(pds[i], 0); + pm_runtime_put(pds[i]); + } +} + +static int qcom_ssc_block_bus_probe(struct platform_device *pdev) +{ + struct qcom_ssc_block_bus_data *data; + struct device_node *np = pdev->dev.of_node; + struct of_phandle_args halt_args; + struct resource *res; + int ret; + + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + platform_set_drvdata(pdev, data); + + data->pd_names = qcom_ssc_block_pd_names; + data->num_pds = ARRAY_SIZE(qcom_ssc_block_pd_names); + + // power domains + ret = qcom_ssc_block_bus_pds_attach(&pdev->dev, data->pds, data->pd_names, data->num_pds); + if (ret < 0) + return dev_err_probe(&pdev->dev, ret, "error when attaching power domains\n"); + + ret = qcom_ssc_block_bus_pds_enable(data->pds, data->num_pds); + if (ret < 0) + return dev_err_probe(&pdev->dev, ret, "error when enabling power domains\n"); + + // the meaning of the bits in these two registers is sadly not documented, + // the set/clear operations are just copying what qcom does + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mpm_sscaon_config0"); + data->reg_mpm_sscaon_config0 = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(data->reg_mpm_sscaon_config0)) + return dev_err_probe(&pdev->dev, PTR_ERR(data->reg_mpm_sscaon_config0), + "Failed to ioremap mpm_sscaon_config0\n"); + + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mpm_sscaon_config1"); + data->reg_mpm_sscaon_config1 = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(data->reg_mpm_sscaon_config1)) + return dev_err_probe(&pdev->dev, PTR_ERR(data->reg_mpm_sscaon_config1), + "Failed to ioremap mpm_sscaon_config1\n"); + + // resets + data->ssc_bcr = devm_reset_control_get_exclusive(&pdev->dev, "ssc_bcr"); + if (IS_ERR(data->ssc_bcr)) + return dev_err_probe(&pdev->dev, PTR_ERR(data->ssc_bcr), + "Failed to acquire reset: scc_bcr\n"); + + data->ssc_reset = devm_reset_control_get_exclusive(&pdev->dev, "ssc_reset"); + if (IS_ERR(data->ssc_reset)) + return dev_err_probe(&pdev->dev, PTR_ERR(data->ssc_reset), + "Failed to acquire reset: ssc_reset:\n"); + + // clocks + data->xo_clk = devm_clk_get(&pdev->dev, "xo"); + if (IS_ERR(data->xo_clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(data->xo_clk), + "Failed to get clock: xo\n"); + + data->aggre2_clk = devm_clk_get(&pdev->dev, "aggre2"); + if (IS_ERR(data->aggre2_clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(data->aggre2_clk), + "Failed to get clock: aggre2\n"); + + data->gcc_im_sleep_clk = devm_clk_get(&pdev->dev, "gcc_im_sleep"); + if (IS_ERR(data->gcc_im_sleep_clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(data->gcc_im_sleep_clk), + "Failed to get clock: gcc_im_sleep\n"); + + data->aggre2_north_clk = devm_clk_get(&pdev->dev, "aggre2_north"); + if (IS_ERR(data->aggre2_north_clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(data->aggre2_north_clk), + "Failed to get clock: aggre2_north\n"); + + data->ssc_xo_clk = devm_clk_get(&pdev->dev, "ssc_xo"); + if (IS_ERR(data->ssc_xo_clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(data->ssc_xo_clk), + "Failed to get clock: ssc_xo\n"); + + data->ssc_ahbs_clk = devm_clk_get(&pdev->dev, "ssc_ahbs"); + if (IS_ERR(data->ssc_ahbs_clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(data->ssc_ahbs_clk), + "Failed to get clock: ssc_ahbs\n"); + + ret = of_parse_phandle_with_fixed_args(pdev->dev.of_node, "qcom,halt-regs", 1, 0, + &halt_args); + if (ret < 0) + return dev_err_probe(&pdev->dev, ret, "Failed to parse qcom,halt-regs\n"); + + data->halt_map = syscon_node_to_regmap(halt_args.np); + of_node_put(halt_args.np); + if (IS_ERR(data->halt_map)) + return PTR_ERR(data->halt_map); + + data->ssc_axi_halt = halt_args.args[0]; + + qcom_ssc_block_bus_init(&pdev->dev); + + of_platform_populate(np, NULL, NULL, &pdev->dev); + + return 0; +} + +static int qcom_ssc_block_bus_remove(struct platform_device *pdev) +{ + struct qcom_ssc_block_bus_data *data = platform_get_drvdata(pdev); + + qcom_ssc_block_bus_deinit(&pdev->dev); + + iounmap(data->reg_mpm_sscaon_config0); + iounmap(data->reg_mpm_sscaon_config1); + + qcom_ssc_block_bus_pds_disable(data->pds, data->num_pds); + qcom_ssc_block_bus_pds_detach(&pdev->dev, data->pds, data->num_pds); + pm_runtime_disable(&pdev->dev); + pm_clk_destroy(&pdev->dev); + + return 0; +} + +static const struct of_device_id qcom_ssc_block_bus_of_match[] = { + { .compatible = "qcom,ssc-block-bus", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, qcom_ssc_block_bus_of_match); + +static struct platform_driver qcom_ssc_block_bus_driver = { + .probe = qcom_ssc_block_bus_probe, + .remove = qcom_ssc_block_bus_remove, + .driver = { + .name = "qcom-ssc-block-bus", + .of_match_table = qcom_ssc_block_bus_of_match, + }, +}; + +module_platform_driver(qcom_ssc_block_bus_driver); + +MODULE_DESCRIPTION("A driver for handling the init sequence needed for accessing the SSC block on (some) qcom SoCs over AHB"); +MODULE_AUTHOR("Michael Srba "); +MODULE_LICENSE("GPL v2");