From mboxrd@z Thu Jan 1 00:00:00 1970 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 221C4C678D5 for ; Wed, 8 Mar 2023 11:14:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231223AbjCHLOo (ORCPT ); Wed, 8 Mar 2023 06:14:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58450 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230326AbjCHLOl (ORCPT ); Wed, 8 Mar 2023 06:14:41 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F243C96F31; Wed, 8 Mar 2023 03:14:38 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 96B9BB81B29; Wed, 8 Mar 2023 11:14:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A75C6C433D2; Wed, 8 Mar 2023 11:14:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1678274076; bh=ccMiXcux3iDGpJ9zg6DwkZ7guZhASt7RFzYQJF/9t+s=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=imuRQSGxW8fc16+YkypSdiDiRiwwiUq5kQ1XaM6LT0ZwSbARikUWRWFPQdnPSCuNg QWwU4Yi86lUjw967W6VdYGt8DvbL0L8BytEwD7+jCzvJ/jNW47f/hxMNrPjnpWt1aV GUxXZ6pnS1tOyuMDyiDihZSDBnEv+vbRkxWrcEJIRm1IjjlVC30jybvqo52Vhy41PG 8EjyJqWWr44SBNYUmaD2UDgl8ctT3KE11V7JGYRtSQ4B3o52KwTVby4sh3LwPIRGzK 2IczxarO5oAIqtvnydOVlb13YNWMtmx6kBae18CV4hAkXQthb545QONkSIPP6au+Rm kdb3ukvzrJxxQ== Message-ID: <4b8d8b8e-9062-e4e6-770b-86bd40cc3683@kernel.org> Date: Wed, 8 Mar 2023 13:14:29 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.7.1 Subject: Re: [EXTERNAL] Re: [PATCH v3 5/6] soc: ti: pruss: Add helper function to enable OCP master ports Content-Language: en-US To: Md Danish Anwar , MD Danish Anwar , "Andrew F. Davis" , Suman Anna , Vignesh Raghavendra , Mathieu Poirier , Bjorn Andersson , Santosh Shilimkar , Nishanth Menon Cc: linux-remoteproc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, srk@ti.com, devicetree@vger.kernel.org, netdev@vger.kernel.org References: <20230306110934.2736465-1-danishanwar@ti.com> <20230306110934.2736465-6-danishanwar@ti.com> <39879d9f-041b-9156-95a5-a81702721739@kernel.org> From: Roger Quadros In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/03/2023 13:09, Md Danish Anwar wrote: > Hi Roger, > > On 08/03/23 14:11, Roger Quadros wrote: >> >> >> On 06/03/2023 13:09, MD Danish Anwar wrote: >>> From: Suman Anna >>> >>> The PRU-ICSS subsystem on OMAP-architecture based SoCS (AM33xx, AM437x >>> and AM57xx SoCs) has a control bit STANDBY_INIT in the PRUSS_CFG register >>> to initiate a Standby sequence (when set) and trigger a MStandby request >>> to the SoC's PRCM module. This same bit is also used to enable the OCP >>> master ports (when cleared). The clearing of the STANDBY_INIT bit requires >>> an acknowledgment from PRCM and is done through the monitoring of the >>> PRUSS_SYSCFG.SUB_MWAIT bit. >>> >>> Add a helper function pruss_cfg_ocp_master_ports() to allow the PRU >>> client drivers to control this bit and enable or disable the firmware >>> running on PRU cores access to any peripherals or memory to achieve >>> desired functionality. The access is disabled by default on power-up >>> and on any suspend (context is not maintained). >>> >>> Signed-off-by: Suman Anna >>> Co-developed-by: Grzegorz Jaszczyk >>> Signed-off-by: Grzegorz Jaszczyk >>> Signed-off-by: Puranjay Mohan >>> --- >>> drivers/soc/ti/pruss.c | 81 +++++++++++++++++++++++++++++++- >>> include/linux/remoteproc/pruss.h | 6 +++ >>> 2 files changed, 85 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/soc/ti/pruss.c b/drivers/soc/ti/pruss.c >>> index 537a3910ffd8..dc3abda0b8c2 100644 >>> --- a/drivers/soc/ti/pruss.c >>> +++ b/drivers/soc/ti/pruss.c >>> @@ -22,14 +22,19 @@ >>> #include >>> #include >>> >>> +#define SYSCFG_STANDBY_INIT BIT(4) >>> +#define SYSCFG_SUB_MWAIT_READY BIT(5) >>> + >>> /** >>> * struct pruss_private_data - PRUSS driver private data >>> * @has_no_sharedram: flag to indicate the absence of PRUSS Shared Data RAM >>> * @has_core_mux_clock: flag to indicate the presence of PRUSS core clock >>> + * @has_ocp_syscfg: flag to indicate if OCP SYSCFG is present >>> */ >>> struct pruss_private_data { >>> bool has_no_sharedram; >>> bool has_core_mux_clock; >>> + bool has_ocp_syscfg; >>> }; >>> >>> /** >>> @@ -205,6 +210,72 @@ int pruss_cfg_update(struct pruss *pruss, unsigned int reg, >>> } >>> EXPORT_SYMBOL_GPL(pruss_cfg_update); >>> >>> +/** >>> + * pruss_cfg_ocp_master_ports() - configure PRUSS OCP master ports >>> + * @pruss: the pruss instance handle >>> + * @enable: set to true for enabling or false for disabling the OCP master ports >>> + * >>> + * This function programs the PRUSS_SYSCFG.STANDBY_INIT bit either to enable or >>> + * disable the OCP master ports (applicable only on SoCs using OCP interconnect >>> + * like the OMAP family). Clearing the bit achieves dual functionalities - one >>> + * is to deassert the MStandby signal to the device PRCM, and the other is to >>> + * enable OCP master ports to allow accesses outside of the PRU-ICSS. The >>> + * function has to wait for the PRCM to acknowledge through the monitoring of >>> + * the PRUSS_SYSCFG.SUB_MWAIT bit when enabling master ports. Setting the bit >>> + * disables the master access, and also signals the PRCM that the PRUSS is ready >>> + * for Standby. >>> + * >>> + * Return: 0 on success, or an error code otherwise. ETIMEDOUT is returned >>> + * when the ready-state fails. >>> + */ >>> +int pruss_cfg_ocp_master_ports(struct pruss *pruss, bool enable) >>> +{ >>> + int ret; >>> + u32 syscfg_val, i; >>> + const struct pruss_private_data *data; >>> + >>> + if (IS_ERR_OR_NULL(pruss)) >>> + return -EINVAL; >>> + >>> + data = of_device_get_match_data(pruss->dev); >>> + >>> + /* nothing to do on non OMAP-SoCs */ >>> + if (!data || !data->has_ocp_syscfg) >>> + return 0; >>> + >>> + /* assert the MStandby signal during disable path */ >>> + if (!enable) >>> + return pruss_cfg_update(pruss, PRUSS_CFG_SYSCFG, >>> + SYSCFG_STANDBY_INIT, >>> + SYSCFG_STANDBY_INIT); >> >> You can omit the above if() if you just encapsulate the below in >> >> if (enable) { >> >> > Sure, I can omit the above if() and put the below block inside if (enable) {}. > > Currently when API pruss_cfg_ocp_master_ports()is called with enable as false > i.e. disabling PRUSS OCP master ports is requested, we directly return > pruss_cfg_update() where as if we remove the above if() section and encapsulate > below block in if (enable) {}, then in disable scenario, call flow will > directly reach the label disable. In the label disable, we are updating cfg and > then returning "ret", but at this point the variable ret is not assigned. > > To counter this should I change the label disable to below? > > disable: > return pruss_cfg_update(pruss, PRUSS_CFG_SYSCFG, SYSCFG_STANDBY_INIT, > SYSCFG_STANDBY_INIT); But you will loose the error code if we came here due to failure in pruss_cfg_read(). It's ok, don't make the change I suggested and leave it as it is. > >>> + >>> + /* enable the OCP master ports and disable MStandby */ >>> + ret = pruss_cfg_update(pruss, PRUSS_CFG_SYSCFG, SYSCFG_STANDBY_INIT, 0); >>> + if (ret) >>> + return ret; >>> + >>> + /* wait till we are ready for transactions - delay is arbitrary */ >>> + for (i = 0; i < 10; i++) { >>> + ret = pruss_cfg_read(pruss, PRUSS_CFG_SYSCFG, &syscfg_val); >>> + if (ret) >>> + goto disable; >>> + > > Changing the disable label will also result in losing the return value of > pruss_cfg_read() API call here. > >>> + if (!(syscfg_val & SYSCFG_SUB_MWAIT_READY)) >>> + return 0; >>> + >>> + udelay(5); >>> + } >>> + >>> + dev_err(pruss->dev, "timeout waiting for SUB_MWAIT_READY\n"); >>> + ret = -ETIMEDOUT; > > Changing the disable label will also result in losing ret = -ETIMEDOUT here. > >> >> } >> >>> + >>> +disable: >>> + pruss_cfg_update(pruss, PRUSS_CFG_SYSCFG, SYSCFG_STANDBY_INIT, >>> + SYSCFG_STANDBY_INIT); >>> + return ret; >>> +} > > So should I do this modification or keep it as it is? > >>> +EXPORT_SYMBOL_GPL(pruss_cfg_ocp_master_ports); >>> + >>> static void pruss_of_free_clk_provider(void *data) >>> { >>> struct device_node *clk_mux_np = data; >>> @@ -495,10 +566,16 @@ static int pruss_remove(struct platform_device *pdev) >>> /* instance-specific driver private data */ >>> static const struct pruss_private_data am437x_pruss1_data = { >>> .has_no_sharedram = false, >>> + .has_ocp_syscfg = true, >>> }; >>> >>> static const struct pruss_private_data am437x_pruss0_data = { >>> .has_no_sharedram = true, >>> + .has_ocp_syscfg = false, >>> +}; >>> + >>> +static const struct pruss_private_data am33xx_am57xx_data = { >>> + .has_ocp_syscfg = true, >>> }; >> >> How about keeping platform data for different platforms separate? >> >> i.e. am33xx_pruss_data and am57xx_pruss_data >> > > Sure. I'll split am33xx_am57xx_data into am33xx_pruss_data and > am57xx_pruss_data as well as am65x_j721e_pruss_data into am65x_pruss_data and > j721e_pruss_data. > >>> >>> static const struct pruss_private_data am65x_j721e_pruss_data = { >>> @@ -506,10 +583,10 @@ static const struct pruss_private_data am65x_j721e_pruss_data = { >>> }; >>> >>> static const struct of_device_id pruss_of_match[] = { >>> - { .compatible = "ti,am3356-pruss" }, >>> + { .compatible = "ti,am3356-pruss", .data = &am33xx_am57xx_data }, >>> { .compatible = "ti,am4376-pruss0", .data = &am437x_pruss0_data, }, >>> { .compatible = "ti,am4376-pruss1", .data = &am437x_pruss1_data, }, >>> - { .compatible = "ti,am5728-pruss" }, >>> + { .compatible = "ti,am5728-pruss", .data = &am33xx_am57xx_data }, >>> { .compatible = "ti,k2g-pruss" }, >>> { .compatible = "ti,am654-icssg", .data = &am65x_j721e_pruss_data, }, >>> { .compatible = "ti,j721e-icssg", .data = &am65x_j721e_pruss_data, }, >>> diff --git a/include/linux/remoteproc/pruss.h b/include/linux/remoteproc/pruss.h >>> index 7952f250301a..8cb99d3cad0d 100644 >>> --- a/include/linux/remoteproc/pruss.h >>> +++ b/include/linux/remoteproc/pruss.h >>> @@ -168,6 +168,7 @@ int pruss_release_mem_region(struct pruss *pruss, >>> int pruss_cfg_read(struct pruss *pruss, unsigned int reg, unsigned int *val); >>> int pruss_cfg_update(struct pruss *pruss, unsigned int reg, >>> unsigned int mask, unsigned int val); >>> +int pruss_cfg_ocp_master_ports(struct pruss *pruss, bool enable); >>> >>> #else >>> >>> @@ -203,6 +204,11 @@ static inline int pruss_cfg_update(struct pruss *pruss, unsigned int reg, >>> return -EOPNOTSUPP; >>> } >>> >>> +static inline int pruss_cfg_ocp_master_ports(struct pruss *pruss, bool enable) >>> +{ >>> + return -EOPNOTSUPP; >>> +} >>> + >>> #endif /* CONFIG_TI_PRUSS */ >>> >>> #if IS_ENABLED(CONFIG_PRU_REMOTEPROC) >> >> cheers, >> -roger > cheers, -roger