From patchwork Thu Oct 18 10:01:27 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Linus Walleij X-Patchwork-Id: 12331 Return-Path: X-Original-To: patchwork@peony.canonical.com Delivered-To: patchwork@peony.canonical.com Received: from fiordland.canonical.com (fiordland.canonical.com [91.189.94.145]) by peony.canonical.com (Postfix) with ESMTP id D55D723DE2 for ; Thu, 18 Oct 2012 10:02:16 +0000 (UTC) Received: from mail-ia0-f180.google.com (mail-ia0-f180.google.com [209.85.210.180]) by fiordland.canonical.com (Postfix) with ESMTP id 696C9A184DE for ; Thu, 18 Oct 2012 10:02:16 +0000 (UTC) Received: by mail-ia0-f180.google.com with SMTP id f6so5997862iag.11 for ; Thu, 18 Oct 2012 03:02:15 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=x-forwarded-to:x-forwarded-for:delivered-to:received-spf:from:to:cc :subject:date:message-id:x-mailer:mime-version:content-type :x-gm-message-state; bh=gUOfGHbhER6E+cFvmUHUno5YHjMWz8E01D5YZEPI+20=; b=oMBor9TnEAZ5szUi+A7fLMESx2zXzq5SIShgX80ZzmgpUfhXxYSgM7RA6nmphjxsmU HfFVZHAKmjh0osETbfCcVk1+luyvcIplQgDRmOFcwa11GF84f/s6hwR4BZtOxpbWczv9 jw3hm2lZbowCTXocWieXKFrBUe9mAqvc7ZY9peKiHuMvE5BgkDXuUzg3sIZ2QGAmhgf4 8uCzlSeG0C87KzCzj7YNE90f+sGLCqlcfZ9c4r44oLEiq4XleK+Ow1k44cbRoVWJAwNo Gr4SZLdmuG7EGZ1vZTvDbGqARqE8SLwAdZsoIZI+hRm/I9iQVuH1K/Wu3TrWGKOgRLKp mTaw== Received: by 10.50.100.137 with SMTP id ey9mr4195591igb.57.1350554535815; Thu, 18 Oct 2012 03:02:15 -0700 (PDT) X-Forwarded-To: linaro-patchwork@canonical.com X-Forwarded-For: patch@linaro.org linaro-patchwork@canonical.com Delivered-To: patches@linaro.org Received: by 10.50.67.148 with SMTP id n20csp1043798igt; Thu, 18 Oct 2012 03:02:14 -0700 (PDT) Received: by 10.14.199.134 with SMTP id x6mr30935866een.31.1350554534304; Thu, 18 Oct 2012 03:02:14 -0700 (PDT) Received: from eu1sys200aog101.obsmtp.com (eu1sys200aog101.obsmtp.com [207.126.144.111]) by mx.google.com with SMTP id f43si18694331eem.114.2012.10.18.03.02.05 (version=TLSv1/SSLv3 cipher=OTHER); Thu, 18 Oct 2012 03:02:14 -0700 (PDT) Received-SPF: neutral (google.com: 207.126.144.111 is neither permitted nor denied by best guess record for domain of linus.walleij@stericsson.com) client-ip=207.126.144.111; Authentication-Results: mx.google.com; spf=neutral (google.com: 207.126.144.111 is neither permitted nor denied by best guess record for domain of linus.walleij@stericsson.com) smtp.mail=linus.walleij@stericsson.com Received: from beta.dmz-us.st.com ([167.4.1.35]) (using TLSv1) by eu1sys200aob101.postini.com ([207.126.147.11]) with SMTP ID DSNKUH/TnaVXGfkjSPG6Xr9KWkuvzDdognpN@postini.com; Thu, 18 Oct 2012 10:02:13 UTC Received: from zeta.dmz-us.st.com (ns4.st.com [167.4.16.71]) by beta.dmz-us.st.com (STMicroelectronics) with ESMTP id 2733C3A; Thu, 18 Oct 2012 10:01:02 +0000 (GMT) Received: from relay2.stm.gmessaging.net (unknown [10.230.100.18]) by zeta.dmz-us.st.com (STMicroelectronics) with ESMTP id 3D69F79; Thu, 18 Oct 2012 05:34:15 +0000 (GMT) Received: from exdcvycastm004.EQ1STM.local (alteon-source-exch [10.230.100.61]) (using TLSv1 with cipher RC4-MD5 (128/128 bits)) (Client CN "exdcvycastm004", Issuer "exdcvycastm004" (not verified)) by relay2.stm.gmessaging.net (Postfix) with ESMTPS id 99A6EA8065; Thu, 18 Oct 2012 12:01:28 +0200 (CEST) Received: from steludxu4075.lud.stericsson.com (10.230.100.153) by smtp.stericsson.com (10.230.100.2) with Microsoft SMTP Server (TLS) id 8.3.83.0; Thu, 18 Oct 2012 12:01:32 +0200 From: Linus Walleij To: , Cc: Stephen Warren , Anmar Oueja , Linus Walleij , Patrice Chotard , Jean Nicolas Graux , Loic Pallardy Subject: [PATCH] pinctrl: reserve pins when states are activated Date: Thu, 18 Oct 2012 12:01:27 +0200 Message-ID: <1350554487-7914-1-git-send-email-linus.walleij@stericsson.com> X-Mailer: git-send-email 1.7.11.3 MIME-Version: 1.0 X-Gm-Message-State: ALoCoQm5ZhUST9K7FrXdk7ZX4KqpVC2p6B9vmYECsONooRfl47W0jndz84OJf8Phh0X63pRe9QMJ From: Linus Walleij This switches the way that pins are reserved for multiplexing: We used to do this when the map was parsed, at the creation of the settings inside the pinctrl handle, in pinmux_map_to_setting(). However this does not work for us, because we want to use the same set of pins with different devices at different times: the current code assumes that the pin groups in a pinmux state will only be used with one single device, albeit different groups can be active at different times. For example if a single I2C driver block is used to drive two different busses located on two pin groups A and B, then the pins for all possible states of a function are reserved when fetching the pinctrl handle: the I2C bus can choose either set A or set B by a mux state at runtime, but all pins in both group A and B (the superset) are effectively reserved for that I2C function and mapped to the device. Another device can never get in and use the pins in group A, even if the device/function is using group B at the moment. Instead: let use reserve the pins when the state is activated and drop them when the state is disabled, i.e. when we move to another state. This way different devices/functions can use the same pins at different times. We know that this is an odd way of doing things, but we really need to switch e.g. an SD-card slot to become a tracing output sink at runtime: we plug in a special "tracing card" then mux the pins that used to be an SD slot around to the tracing unit and push out tracing data there instead of SD-card traffic. Cc: Patrice Chotard Cc: Jean Nicolas Graux Cc: Loic Pallardy Signed-off-by: Linus Walleij --- Documentation/pinctrl.txt | 4 ++- drivers/pinctrl/core.c | 2 ++ drivers/pinctrl/core.h | 2 ++ drivers/pinctrl/pinmux.c | 70 +++++++++++++++++------------------------------ 4 files changed, 32 insertions(+), 46 deletions(-) diff --git a/Documentation/pinctrl.txt b/Documentation/pinctrl.txt index 3b4ee53..a1cd2f9 100644 --- a/Documentation/pinctrl.txt +++ b/Documentation/pinctrl.txt @@ -1193,4 +1193,6 @@ foo_switch() ... } -The above has to be done from process context. +The above has to be done from process context. The reservation of the pins +will be done when the state is activated, so in effect one specific pin +can be used by different functions at different times on a running system. diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c index 0f1ec9e..5c6dff2 100644 --- a/drivers/pinctrl/core.c +++ b/drivers/pinctrl/core.c @@ -563,6 +563,8 @@ static int add_setting(struct pinctrl *p, struct pinctrl_map const *map) return -EPROBE_DEFER; } + setting->dev_name = map->dev_name; + switch (map->type) { case PIN_MAP_TYPE_MUX_GROUP: ret = pinmux_map_to_setting(map, setting); diff --git a/drivers/pinctrl/core.h b/drivers/pinctrl/core.h index 1f40ff6..12f5694 100644 --- a/drivers/pinctrl/core.h +++ b/drivers/pinctrl/core.h @@ -105,12 +105,14 @@ struct pinctrl_setting_configs { * @type: the type of setting * @pctldev: pin control device handling to be programmed. Not used for * PIN_MAP_TYPE_DUMMY_STATE. + * @dev_name: the name of the device using this state * @data: Data specific to the setting type */ struct pinctrl_setting { struct list_head node; enum pinctrl_map_type type; struct pinctrl_dev *pctldev; + const char *dev_name; union { struct pinctrl_setting_mux mux; struct pinctrl_setting_configs configs; diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c index 9301a7a..dadc891 100644 --- a/drivers/pinctrl/pinmux.c +++ b/drivers/pinctrl/pinmux.c @@ -314,14 +314,11 @@ int pinmux_map_to_setting(struct pinctrl_map const *map, { struct pinctrl_dev *pctldev = setting->pctldev; const struct pinmux_ops *pmxops = pctldev->desc->pmxops; - const struct pinctrl_ops *pctlops = pctldev->desc->pctlops; char const * const *groups; unsigned num_groups; int ret; const char *group; int i; - const unsigned *pins; - unsigned num_pins; if (!pmxops) { dev_err(pctldev->dev, "does not support mux function\n"); @@ -376,53 +373,15 @@ int pinmux_map_to_setting(struct pinctrl_map const *map, } setting->data.mux.group = ret; - ret = pctlops->get_group_pins(pctldev, setting->data.mux.group, &pins, - &num_pins); - if (ret) { - dev_err(pctldev->dev, - "could not get pins for device %s group selector %d\n", - pinctrl_dev_get_name(pctldev), setting->data.mux.group); - return -ENODEV; - } - - /* Try to allocate all pins in this group, one by one */ - for (i = 0; i < num_pins; i++) { - ret = pin_request(pctldev, pins[i], map->dev_name, NULL); - if (ret) { - dev_err(pctldev->dev, - "could not request pin %d on device %s\n", - pins[i], pinctrl_dev_get_name(pctldev)); - /* On error release all taken pins */ - i--; /* this pin just failed */ - for (; i >= 0; i--) - pin_free(pctldev, pins[i], NULL); - return -ENODEV; - } - } - return 0; } void pinmux_free_setting(struct pinctrl_setting const *setting) { - struct pinctrl_dev *pctldev = setting->pctldev; - const struct pinctrl_ops *pctlops = pctldev->desc->pctlops; - const unsigned *pins; - unsigned num_pins; - int ret; - int i; - - ret = pctlops->get_group_pins(pctldev, setting->data.mux.group, - &pins, &num_pins); - if (ret) { - dev_err(pctldev->dev, - "could not get pins for device %s group selector %d\n", - pinctrl_dev_get_name(pctldev), setting->data.mux.group); - return; - } - - for (i = 0; i < num_pins; i++) - pin_free(pctldev, pins[i], NULL); + /* + * If a setting is active, disable it so that all pins are released + */ + pinmux_disable_setting(setting); } int pinmux_enable_setting(struct pinctrl_setting const *setting) @@ -446,6 +405,22 @@ int pinmux_enable_setting(struct pinctrl_setting const *setting) num_pins = 0; } + /* Try to allocate all pins in this group, one by one */ + for (i = 0; i < num_pins; i++) { + ret = pin_request(pctldev, pins[i], setting->dev_name, NULL); + if (ret) { + dev_err(pctldev->dev, + "could not request pin %d on device %s\n", + pins[i], pinctrl_dev_get_name(pctldev)); + /* On error release all taken pins */ + i--; /* this pin just failed */ + for (; i >= 0; i--) + pin_free(pctldev, pins[i], NULL); + return -ENODEV; + } + } + + /* Now that we have acquired the pins, encode the mux setting */ for (i = 0; i < num_pins; i++) { desc = pin_desc_get(pctldev, pins[i]); if (desc == NULL) { @@ -482,6 +457,7 @@ void pinmux_disable_setting(struct pinctrl_setting const *setting) num_pins = 0; } + /* Flag the descs that no setting is active */ for (i = 0; i < num_pins; i++) { desc = pin_desc_get(pctldev, pins[i]); if (desc == NULL) { @@ -493,6 +469,10 @@ void pinmux_disable_setting(struct pinctrl_setting const *setting) desc->mux_setting = NULL; } + /* And release the pins */ + for (i = 0; i < num_pins; i++) + pin_free(pctldev, pins[i], NULL); + if (ops->disable) ops->disable(pctldev, setting->data.mux.func, setting->data.mux.group); }