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From: Doug Anderson <dianders@chromium.org> To: Maulik Shah <mkshah@codeaurora.org> Cc: Andy Gross <agross@kernel.org>, Bjorn Andersson <bjorn.andersson@linaro.org>, Rajendra Nayak <rnayak@codeaurora.org>, Matthias Kaehlcke <mka@chromium.org>, Evan Green <evgreen@chromium.org>, Stephen Boyd <swboyd@chromium.org>, Lina Iyer <ilina@codeaurora.org>, linux-arm-msm <linux-arm-msm@vger.kernel.org>, LKML <linux-kernel@vger.kernel.org> Subject: Re: [RFT PATCH 2/9] drivers: qcom: rpmh-rsc: Document the register layout better Date: Wed, 11 Mar 2020 08:27:44 -0700 [thread overview] Message-ID: <CAD=FV=W5RGwu=ywtM7aCv3H-EpJ1i23S0awgVc8QtOsXtige4w@mail.gmail.com> (raw) In-Reply-To: <285d3315-7558-d9f6-fe65-24d8ad07949d@codeaurora.org> Hi, On Wed, Mar 11, 2020 at 2:35 AM Maulik Shah <mkshah@codeaurora.org> wrote: > > Hi Doug, > > On 3/7/2020 5:29 AM, Douglas Anderson wrote: > > Perhaps it's just me, it took a really long time to understand what > > the register layout of rpmh-rsc was just from the #defines. > i don't understand why register layout is so important for you to understand? > > besides, i think all required registers are properly named with #define > > for e.g. > /* Register offsets */ > #define RSC_DRV_IRQ_ENABLE 0x00 > #define RSC_DRV_IRQ_STATUS 0x04 > #define RSC_DRV_IRQ_CLEAR 0x08 > > now when you want to enable/disable irq in driver code, its pretty simple to figure out > that we need to read/write at RSC_DRV_IRQ_ENABLE offset. It's not the specific layout that's important to me. It's the relationships between everything. In other words: a) one rpmh-rsc contains some registers and then a whole bunch of TCS blocks b) one TCS block contains some registers and space for up to 16 commands. c) each command has a handful of registers Nothing describes this in the existing code--you've gotta read through all the code and figure out how it's reading/writing registers to figure it out. > this seems unnecessary change to me, can you please drop this when you spin v2? In v2 I'll replace this with the prose below. Personally I find this inferior to the struct definitions which are easier to read at-a-glance, but it seems like it would be less controversial... /* * Here's a high level overview of how all the registers in RPMH work * together: * * - The main rpmh-rsc address is the base of a register space that can * be used to find overall configuration of the hardware * (DRV_PRNT_CHLD_CONFIG). Also found within the rpmh-rsc register * space are all the TCS blocks. The offset of the TCS blocks is * specified in the device tree by "qcom,tcs-offset" and used to * compute tcs_base. * - TCS blocks come one after another. Type, count, and order are * specified by the device tree as "qcom,tcs-config". * - Each TCS block has some registers, then space for up to 16 commands. * Note that though address space is reserved for 16 commands, fewer * might be present. See ncpt (num cmds per TCS). * - The first TCS block is special in that it has registers to control * interrupts (RSC_DRV_IRQ_XXX). Space for these registers is reserved * in all TCS blocks to make the math easier, but only the first one * matters. */ I'll also move the documentation of "irq_clear", "cmd_wait_for_cmpl", "status", and "cmd_enable" next to the respective #defines.
next prev parent reply other threads:[~2020-03-11 15:28 UTC|newest] Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-03-06 23:59 [RFT PATCH 0/9] drivers: qcom: rpmh-rsc: Cleanup / add lots of comments Douglas Anderson 2020-03-06 23:59 ` [RFT PATCH 1/9] drivers: qcom: rpmh-rsc: Clean code reading/writing regs/cmds Douglas Anderson 2020-03-11 8:47 ` Maulik Shah 2020-03-11 15:03 ` Doug Anderson 2020-03-11 16:17 ` Matthias Kaehlcke 2020-03-11 19:30 ` Stephen Boyd 2020-03-06 23:59 ` [RFT PATCH 2/9] drivers: qcom: rpmh-rsc: Document the register layout better Douglas Anderson 2020-03-11 9:35 ` Maulik Shah 2020-03-11 15:27 ` Doug Anderson [this message] 2020-03-11 18:49 ` Evan Green 2020-03-11 20:08 ` Stephen Boyd 2020-03-11 22:35 ` Doug Anderson 2020-03-06 23:59 ` [RFT PATCH 3/9] drivers: qcom: rpmh-rsc: Fold tcs_ctrl_write() into its single caller Douglas Anderson 2020-03-11 9:50 ` Maulik Shah 2020-03-06 23:59 ` [RFT PATCH 4/9] drivers: qcom: rpmh-rsc: Remove get_tcs_of_type() abstraction Douglas Anderson 2020-03-11 12:02 ` Maulik Shah 2020-03-06 23:59 ` [RFT PATCH 5/9] drivers: qcom: rpmh-rsc: A lot of comments Douglas Anderson 2020-03-06 23:59 ` [RFT PATCH 6/9] drivers: qcom: rpmh-rsc: Only use "tcs_in_use" for ACTIVE_ONLY Douglas Anderson 2020-03-11 0:33 ` Doug Anderson 2020-03-06 23:59 ` [RFT PATCH 7/9] drivers: qcom: rpmh-rsc: Warning if tcs_write() used for non-active Douglas Anderson 2020-03-06 23:59 ` [RFT PATCH 8/9] drivers: qcom: rpmh-rsc: spin_lock_irqsave() for tcs_invalidate() Douglas Anderson 2020-03-06 23:59 ` [RFT PATCH 9/9] drivers: qcom: rpmh-rsc: Kill cmd_cache and find_match() with fire Douglas Anderson 2020-03-11 0:35 ` Doug Anderson 2020-03-11 9:48 ` [RFT PATCH 0/9] drivers: qcom: rpmh-rsc: Cleanup / add lots of comments Maulik Shah
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