From patchwork Wed Sep 30 15:28:15 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 255513 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BB49BC4727E for ; Wed, 30 Sep 2020 15:29:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7D93F20759 for ; Wed, 30 Sep 2020 15:29:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731018AbgI3P3M (ORCPT ); Wed, 30 Sep 2020 11:29:12 -0400 Received: from retiisi.org.uk ([95.216.213.190]:44670 "EHLO hillosipuli.retiisi.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731003AbgI3P3L (ORCPT ); Wed, 30 Sep 2020 11:29:11 -0400 Received: from lanttu.localdomain (lanttu-e.localdomain [192.168.1.64]) by hillosipuli.retiisi.eu (Postfix) with ESMTP id 578B8634CE0 for ; Wed, 30 Sep 2020 18:28:51 +0300 (EEST) From: Sakari Ailus To: linux-media@vger.kernel.org Subject: [PATCH 057/100] ccs-pll: Document the structs in the header as well as the function Date: Wed, 30 Sep 2020 18:28:15 +0300 Message-Id: <20200930152858.8471-58-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200930152858.8471-1-sakari.ailus@linux.intel.com> References: <20200930152858.8471-1-sakari.ailus@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org The CCS pll is used by the CCS driver at the moment, but documenting the interface makes sense. It's non-trivial and the calculator could be used elsewhere. Signed-off-by: Sakari Ailus --- drivers/media/i2c/ccs-pll.h | 88 +++++++++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) diff --git a/drivers/media/i2c/ccs-pll.h b/drivers/media/i2c/ccs-pll.h index 1d908b23c934..e01359f61476 100644 --- a/drivers/media/i2c/ccs-pll.h +++ b/drivers/media/i2c/ccs-pll.h @@ -20,6 +20,16 @@ #define CCS_PLL_FLAG_OP_PIX_CLOCK_PER_LANE (1 << 0) #define CCS_PLL_FLAG_NO_OP_CLOCKS (1 << 1) +/** + * struct ccs_pll_branch_fr - CCS PLL configuration (front) + * + * A single branch front-end of the CCS PLL tree. + * + * @pre_pll_clk_div: Pre-PLL clock divisor + * @pll_multiplier: PLL multiplier + * @pll_ip_freq_hz: PLL input clock frequency + * @pll_op_freq_hz: PLL output clock frequency + */ struct ccs_pll_branch_fr { uint16_t pre_pll_clk_div; uint16_t pll_multiplier; @@ -27,6 +37,16 @@ struct ccs_pll_branch_fr { uint32_t pll_op_clk_freq_hz; }; +/** + * struct ccs_pll_branch_bk - CCS PLL configuration (back) + * + * A single branch back-end of the CCS PLL tree. + * + * @sys_clk_div: System clock divider + * @pix_clk_div: Pixel clock divider + * @sys_clk_freq_hz: System clock frequency + * @pix_clk_freq_hz: Pixel clock frequency + */ struct ccs_pll_branch_bk { uint16_t sys_clk_div; uint16_t pix_clk_div; @@ -34,6 +54,29 @@ struct ccs_pll_branch_bk { uint32_t pix_clk_freq_hz; }; +/** + * struct ccs_pll - Full CCS PLL configuration + * + * All information required to calculate CCS PLL configuration. + * + * @bus_type: Type of the data bus, CCS_PLL_BUS_TYPE_* (input) + * @csi2.lanes: The number of the CSI-2 data lanes (input) + * @binning_vertical: Vertical binning factor (input) + * @binning_horizontal: Horizontal binning factor (input) + * @scale_m: Downscaling factor, M component, [16, max] (input) + * @scale_n: Downscaling factor, N component, typically 16 (input) + * @bits_per_pixel: Bits per pixel on the output data bus (input) + * @flags: CCS_PLL_FLAG_* (input) + * @link_freq: Chosen link frequency (input) + * @ext_clk_freq_hz: External clock frequency, i.e. the sensor's input clock + * (input) + * @vt_fr: Video timing front-end configuration (output) + * @vt_bk: Video timing back-end configuration (output) + * @op_bk: Operational timing back-end configuration (output) + * @pixel_rate_csi: Pixel rate on the output data bus (output) + * @pixel_rate_pixel_array: Nominal pixel rate in the sensor's pixel array + * (output) + */ struct ccs_pll { /* input values */ uint8_t bus_type; @@ -58,6 +101,18 @@ struct ccs_pll { uint32_t pixel_rate_pixel_array; }; +/** + * struct ccs_pll_branch_limits_fr - CCS PLL front-end limits + * + * @min_pre_pll_clk_div: Minimum pre-PLL clock divider + * @max_pre_pll_clk_div: Maximum pre-PLL clock divider + * @min_pll_ip_freq_hz: Minimum PLL input clock frequency + * @max_pll_ip_freq_hz: Maximum PLL input clock frequency + * @min_pll_multiplier: Minimum PLL multiplier + * @max_pll_multiplier: Maximum PLL multiplier + * @min_pll_op_freq_hz: Minimum PLL output clock frequency + * @max_pll_op_freq_hz: Maximum PLL output clock frequency + */ struct ccs_pll_branch_limits_fr { uint16_t min_pre_pll_clk_div; uint16_t max_pre_pll_clk_div; @@ -69,6 +124,18 @@ struct ccs_pll_branch_limits_fr { uint32_t max_pll_op_clk_freq_hz; }; +/** + * struct ccs_pll_branch_limits_bk - CCS PLL back-end limits + * + * @min_sys_clk_div: Minimum system clock divider + * @max_sys_clk_div: Maximum system clock divider + * @min_sys_clk_freq_hz: Minimum system clock frequency + * @max_sys_clk_freq_hz: Maximum system clock frequency + * @min_pix_clk_div: Minimum pixel clock divider + * @max_pix_clk_div: Maximum pixel clock divider + * @min_pix_clk_freq_hz: Minimum pixel clock frequency + * @max_pix_clk_freq_hz: Maximum pixel clock frequency + */ struct ccs_pll_branch_limits_bk { uint16_t min_sys_clk_div; uint16_t max_sys_clk_div; @@ -80,6 +147,17 @@ struct ccs_pll_branch_limits_bk { uint32_t max_pix_clk_freq_hz; }; +/** + * struct ccs_pll_limits - CCS PLL limits + * + * @min_ext_clk_freq_hz: Minimum external clock frequency + * @max_ext_clk_freq_hz: Maximum external clock frequency + * @vt_fr: Video timing front-end limits + * @vt_bk: Video timing back-end limits + * @op_bk: Operational timing back-end limits + * @min_line_length_pck_bin: Minimum line length in pixels, with binning + * @min_line_length_pck: Minimum line length in pixels without binning + */ struct ccs_pll_limits { /* Strict PLL limits */ uint32_t min_ext_clk_freq_hz; @@ -96,6 +174,16 @@ struct ccs_pll_limits { struct device; +/** + * ccs_pll_calculate - Calculate CCS PLL configuration based on input parameters + * + * @dev: Device pointer, used for printing messages + * @limits: Limits specific to the sensor + * @pll: Given PLL configuration + * + * Calculate the CCS PLL configuration based on the limits as well as given + * device specific, system specific or user configured input data. + */ int ccs_pll_calculate(struct device *dev, const struct ccs_pll_limits *limits, struct ccs_pll *pll);