From patchwork Mon Sep 5 12:29:25 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Linus Walleij X-Patchwork-Id: 75379 Delivered-To: patch@linaro.org Received: by 10.140.106.11 with SMTP id d11csp49705qgf; Mon, 5 Sep 2016 05:29:46 -0700 (PDT) X-Received: by 10.66.26.82 with SMTP id j18mr18339222pag.4.1473078586184; Mon, 05 Sep 2016 05:29:46 -0700 (PDT) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id d7si15150637pfg.5.2016.09.05.05.29.43; Mon, 05 Sep 2016 05:29:46 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-arm-msm-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=neutral (body hash did not verify) header.i=@linaro.org; spf=pass (google.com: best guess record for domain of linux-arm-msm-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-arm-msm-owner@vger.kernel.org; dmarc=fail (p=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754726AbcIEM3m (ORCPT + 8 others); Mon, 5 Sep 2016 08:29:42 -0400 Received: from mail-lf0-f53.google.com ([209.85.215.53]:34100 "EHLO mail-lf0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755428AbcIEM3k (ORCPT ); Mon, 5 Sep 2016 08:29:40 -0400 Received: by mail-lf0-f53.google.com with SMTP id u14so2886837lfd.1 for ; Mon, 05 Sep 2016 05:29:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=9Tp9Kop4dbfKnqs2CoThJ+n/trBBp6hgK+KA2YbMB9M=; b=L3WUUCknuPAVscNBmrkhjpz3yDekN2VjcVEXXuZbrRlYoThJp/ZjrpivzazbAt9Hh4 5dJnUQFTnDD1qsHGXF+AiaA4/izcekf9HK06CAS3ijkLqbjWwmp/3+HDO46xzlDsa9Lu 4zvgO6PsjHh+jwv6KrEmJwiqRP2BDSKHgulnA= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=9Tp9Kop4dbfKnqs2CoThJ+n/trBBp6hgK+KA2YbMB9M=; b=Tc4UZLOYjntIZc/qJ5EKg/EzEENsKhJDQwvCGA7QW0t9eJtOKfGt9oiNSQ2dR3RUPi Fn6s87Uq9Mccyi21PahR+8WeVtxwn9AZrmaXzcDhkb/Nq5R/5RPTc/aLZe1bgxFTiw4y Tg/EAaPmj5EJJ4fKjAwFxTObbf8JMgjOo7k9oUA3vp7ExHPJ1IKfKrrgDMmAE8pT5pfq YFs7+Qfl1Yi1px0y4y8tH+gqCGi4ZBV7A4Sx/8wbrGkz6Oria1JdMdCOWg/kgULv2ehy zQWOzssB2YmAzeXKPVUeV6NTUYU64Jiu2xW+4/7WAtUUKL0v8m3/CtavRzbIGV/xl4Rh a/xg== X-Gm-Message-State: AE9vXwMiHexOi7TjbI9qk7TW8h6YAH0DJKrNEbVPdB2VnIqdb4KgXIKxuPq+jUoNYk+cPYh0 X-Received: by 10.46.0.204 with SMTP id e73mr10115185lji.56.1473078578830; Mon, 05 Sep 2016 05:29:38 -0700 (PDT) Received: from linuslaptop.ideon.se ([85.235.10.227]) by smtp.gmail.com with ESMTPSA id 17sm1016615ljj.47.2016.09.05.05.29.37 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 05 Sep 2016 05:29:38 -0700 (PDT) From: Linus Walleij To: linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org, Andy Gross , Rob Herring , devicetree@vger.kernel.org Cc: Stephen Boyd , Bjorn Andersson , David Brown , Linus Walleij Subject: [PATCH 2/2 v5] bus: qcom: add EBI2 driver Date: Mon, 5 Sep 2016 14:29:25 +0200 Message-Id: <1473078565-24363-2-git-send-email-linus.walleij@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1473078565-24363-1-git-send-email-linus.walleij@linaro.org> References: <1473078565-24363-1-git-send-email-linus.walleij@linaro.org> Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org This adds a driver for the Qualcomm External Bus Interface EBI2 found in the MSM8660 and APQ8060 SoCs (at least). This was tested with the SMSC9112 ethernet on the APQ8060 Dragonboard sitting on top of the SLOW CS2. Some of my understanding if very vague and based on guesses and extrapolations: the documentation in APQ8060 Qualcomm Application Processor User Guide 80-N7150-14 Rev. A describes select features but does not document the register bit fields. Signed-off-by: Linus Walleij --- ChangeLog v4->v5: - Reflect the fact that we moved the per-CS special config settings into the devices themselves. ChangeLog v3->v4: - Drop the use of readl/writel_relaxed() accessors, there is no performance boost to be gained to stick with the convention. - Make it possible to build the driver as a module. ChangeLog v2->v3: - Change subject to bus: to reflect the right subsystem. ChangeLog v1->v2: - Move the driver to drivers/bus with other external bus interfaces after realizing that is what it is. - Drop the default y for MACH_MSM8660, let's deal with this through defconfig instead. - Support compatible strings "qcom,msm8660-ebi2" and "qcom,apq8060-ebi2" - Augmented to handle a vendor prefix in fron of every XMEM property "qcom,xmem-foo" - Augment bit placement for CSn enablement: CS0, CS1, CS4 and CS5 being two bits wide - Remove some guesswork around register assignment after feedback from sboyd. (Thanks!) - Handle the errorpath by disabling clocks in a better way. - Break out a per-CS setup function - Walk the children and activate the CS that are actually in use - Parse the XMEM settings from the EBI2 node array of settings per-chipselect in accordance with the new bindings. - Silence a bunch of debug prints to dev_dbg() keep one line for CS setup because it is helpful for quick diagnosing any problems. --- drivers/bus/Kconfig | 7 + drivers/bus/Makefile | 1 + drivers/bus/qcom-ebi2.c | 408 ++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 416 insertions(+) create mode 100644 drivers/bus/qcom-ebi2.c -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig index 3b205e212337..952eeebe0b79 100644 --- a/drivers/bus/Kconfig +++ b/drivers/bus/Kconfig @@ -108,6 +108,13 @@ config OMAP_OCP2SCP OCP2SCP and in OMAP5, both USB PHY and SATA PHY is connected via OCP2SCP. +config QCOM_EBI2 + bool "Qualcomm External Bus Interface 2 (EBI2)" + help + Say y here to enable support for the Qualcomm External Bus + Interface 2, which can be used to connect things like NAND Flash, + SRAM, ethernet adapters, FPGAs and LCD displays. + config SIMPLE_PM_BUS bool "Simple Power-Managed Bus Driver" depends on OF && PM diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile index ac84cc4348e3..c6cfa6b2606e 100644 --- a/drivers/bus/Makefile +++ b/drivers/bus/Makefile @@ -15,6 +15,7 @@ obj-$(CONFIG_MVEBU_MBUS) += mvebu-mbus.o obj-$(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-$(CONFIG_SUNXI_RSB) += sunxi-rsb.o obj-$(CONFIG_SIMPLE_PM_BUS) += simple-pm-bus.o obj-$(CONFIG_TEGRA_ACONNECT) += tegra-aconnect.o diff --git a/drivers/bus/qcom-ebi2.c b/drivers/bus/qcom-ebi2.c new file mode 100644 index 000000000000..a6444244c411 --- /dev/null +++ b/drivers/bus/qcom-ebi2.c @@ -0,0 +1,408 @@ +/* + * Qualcomm External Bus Interface 2 (EBI2) driver + * an older version of the Qualcomm Parallel Interface Controller (QPIC) + * + * Copyright (C) 2016 Linaro Ltd. + * + * Author: Linus Walleij + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2, as + * published by the Free Software Foundation. + * + * See the device tree bindings for this block for more details on the + * hardware. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * CS0, CS1, CS4 and CS5 are two bits wide, CS2 and CS3 are one bit. + */ +#define EBI2_CS0_ENABLE_MASK BIT(0)|BIT(1) +#define EBI2_CS1_ENABLE_MASK BIT(2)|BIT(3) +#define EBI2_CS2_ENABLE_MASK BIT(4) +#define EBI2_CS3_ENABLE_MASK BIT(5) +#define EBI2_CS4_ENABLE_MASK BIT(6)|BIT(7) +#define EBI2_CS5_ENABLE_MASK BIT(8)|BIT(9) +#define EBI2_CSN_MASK GENMASK(9, 0) + +#define EBI2_XMEM_CFG 0x0000 /* Power management etc */ + +/* + * SLOW CSn CFG + * + * Bits 31-28: RECOVERY recovery cycles (0 = 1, 1 = 2 etc) this is the time the + * memory continues to drive the data bus after OE is de-asserted. + * Inserted when reading one CS and switching to another CS or read + * followed by write on the same CS. Valid values 0 thru 15. + * Bits 27-24: WR_HOLD write hold cycles, these are extra cycles inserted after + * every write minimum 1. The data out is driven from the time WE is + * asserted until CS is asserted. With a hold of 1, the CS stays + * active for 1 extra cycle etc. Valid values 0 thru 15. + * Bits 23-16: WR_DELTA initial latency for write cycles inserted for the first + * write to a page or burst memory + * Bits 15-8: RD_DELTA initial latency for read cycles inserted for the first + * read to a page or burst memory + * Bits 7-4: WR_WAIT number of wait cycles for every write access, 0=1 cycle + * so 1 thru 16 cycles. + * Bits 3-0: RD_WAIT number of wait cycles for every read access, 0=1 cycle + * so 1 thru 16 cycles. + */ +#define EBI2_XMEM_CS0_SLOW_CFG 0x0008 +#define EBI2_XMEM_CS1_SLOW_CFG 0x000C +#define EBI2_XMEM_CS2_SLOW_CFG 0x0010 +#define EBI2_XMEM_CS3_SLOW_CFG 0x0014 +#define EBI2_XMEM_CS4_SLOW_CFG 0x0018 +#define EBI2_XMEM_CS5_SLOW_CFG 0x001C + +#define EBI2_XMEM_RECOVERY_SHIFT 28 +#define EBI2_XMEM_WR_HOLD_SHIFT 24 +#define EBI2_XMEM_WR_DELTA_SHIFT 16 +#define EBI2_XMEM_RD_DELTA_SHIFT 8 +#define EBI2_XMEM_WR_WAIT_SHIFT 4 +#define EBI2_XMEM_RD_WAIT_SHIFT 0 + +/* + * FAST CSn CFG + * Bits 31-28: ? + * Bits 27-24: RD_HOLD: the length in cycles of the first segment of a read + * transfer. For a single read trandfer this will be the time + * from CS assertion to OE assertion. + * Bits 18-24: ? + * Bits 17-16: ADV_OE_RECOVERY, the number of cycles elapsed before an OE + * assertion, with respect to the cycle where ADV is asserted. + * 2 means 2 cycles between ADV and OE. Values 0, 1, 2 or 3. + * Bits 5: ADDR_HOLD_ENA, The address is held for an extra cycle to meet + * hold time requirements with ADV assertion. + * + * The manual mentions "write precharge cycles" and "precharge cycles". + * We have not been able to figure out which bit fields these correspond to + * in the hardware, or what valid values exist. The current hypothesis is that + * this is something just used on the FAST chip selects. There is also a "byte + * device enable" flag somewhere for 8bit memories. + */ +#define EBI2_XMEM_CS0_FAST_CFG 0x0028 +#define EBI2_XMEM_CS1_FAST_CFG 0x002C +#define EBI2_XMEM_CS2_FAST_CFG 0x0030 +#define EBI2_XMEM_CS3_FAST_CFG 0x0034 +#define EBI2_XMEM_CS4_FAST_CFG 0x0038 +#define EBI2_XMEM_CS5_FAST_CFG 0x003C + +#define EBI2_XMEM_RD_HOLD_SHIFT 24 +#define EBI2_XMEM_ADV_OE_RECOVERY_SHIFT 16 +#define EBI2_XMEM_ADDR_HOLD_ENA_SHIFT 5 + +/** + * struct cs_data - struct with info on a chipselect setting + * @enable_mask: mask to enable the chipselect in the EBI2 config + * @slow_cfg0: offset to XMEMC slow CS config + * @fast_cfg1: offset to XMEMC fast CS config + */ +struct cs_data { + u32 enable_mask; + u16 slow_cfg; + u16 fast_cfg; +}; + +static const struct cs_data cs_info[] = { + { + /* CS0 */ + .enable_mask = EBI2_CS0_ENABLE_MASK, + .slow_cfg = EBI2_XMEM_CS0_SLOW_CFG, + .fast_cfg = EBI2_XMEM_CS0_FAST_CFG, + }, + { + /* CS1 */ + .enable_mask = EBI2_CS1_ENABLE_MASK, + .slow_cfg = EBI2_XMEM_CS1_SLOW_CFG, + .fast_cfg = EBI2_XMEM_CS1_FAST_CFG, + }, + { + /* CS2 */ + .enable_mask = EBI2_CS2_ENABLE_MASK, + .slow_cfg = EBI2_XMEM_CS2_SLOW_CFG, + .fast_cfg = EBI2_XMEM_CS2_FAST_CFG, + }, + { + /* CS3 */ + .enable_mask = EBI2_CS3_ENABLE_MASK, + .slow_cfg = EBI2_XMEM_CS3_SLOW_CFG, + .fast_cfg = EBI2_XMEM_CS3_FAST_CFG, + }, + { + /* CS4 */ + .enable_mask = EBI2_CS4_ENABLE_MASK, + .slow_cfg = EBI2_XMEM_CS4_SLOW_CFG, + .fast_cfg = EBI2_XMEM_CS4_FAST_CFG, + }, + { + /* CS5 */ + .enable_mask = EBI2_CS5_ENABLE_MASK, + .slow_cfg = EBI2_XMEM_CS5_SLOW_CFG, + .fast_cfg = EBI2_XMEM_CS5_FAST_CFG, + }, +}; + +/** + * struct ebi2_xmem_prop - describes an XMEM config property + * @prop: the device tree binding name + * @max: maximum value for the property + * @slowreg: true if this property is in the SLOW CS config register + * else it is assumed to be in the FAST config register + * @shift: the bit field start in the SLOW or FAST register for this + * property + */ +struct ebi2_xmem_prop { + const char *prop; + u32 max; + bool slowreg; + u16 shift; +}; + +static const struct ebi2_xmem_prop xmem_props[] = { + { + .prop = "qcom,xmem-recovery-cycles", + .max = 15, + .slowreg = true, + .shift = EBI2_XMEM_RECOVERY_SHIFT, + }, + { + .prop = "qcom,xmem-write-hold-cycles", + .max = 15, + .slowreg = true, + .shift = EBI2_XMEM_WR_HOLD_SHIFT, + }, + { + .prop = "qcom,xmem-write-delta-cycles", + .max = 255, + .slowreg = true, + .shift = EBI2_XMEM_WR_DELTA_SHIFT, + }, + { + .prop = "qcom,xmem-read-delta-cycles", + .max = 255, + .slowreg = true, + .shift = EBI2_XMEM_RD_DELTA_SHIFT, + }, + { + .prop = "qcom,xmem-write-wait-cycles", + .max = 15, + .slowreg = true, + .shift = EBI2_XMEM_WR_WAIT_SHIFT, + }, + { + .prop = "qcom,xmem-read-wait-cycles", + .max = 15, + .slowreg = true, + .shift = EBI2_XMEM_RD_WAIT_SHIFT, + }, + { + .prop = "qcom,xmem-address-hold-enable", + .max = 1, /* boolean prop */ + .slowreg = false, + .shift = EBI2_XMEM_ADDR_HOLD_ENA_SHIFT, + }, + { + .prop = "qcom,xmem-adv-to-oe-recovery-cycles", + .max = 3, + .slowreg = false, + .shift = EBI2_XMEM_ADV_OE_RECOVERY_SHIFT, + }, + { + .prop = "qcom,xmem-read-hold-cycles", + .max = 15, + .slowreg = false, + .shift = EBI2_XMEM_RD_HOLD_SHIFT, + }, +}; + +static void qcom_ebi2_setup_chipselect(struct device_node *np, + struct device *dev, + void __iomem *ebi2_base, + void __iomem *ebi2_xmem, + u32 csindex) +{ + const struct cs_data *csd; + u32 slowcfg, fastcfg; + u32 val; + int ret; + int i; + + csd = &cs_info[csindex]; + val = readl(ebi2_base); + val |= csd->enable_mask; + writel(val, ebi2_base); + dev_dbg(dev, "enabled CS%u\n", csindex); + + /* Next set up the XMEMC */ + slowcfg = 0; + fastcfg = 0; + + for (i = 0; i < ARRAY_SIZE(xmem_props); i++) { + const struct ebi2_xmem_prop *xp = &xmem_props[i]; + + /* All are regular u32 values */ + ret = of_property_read_u32(np, xp->prop, &val); + if (ret) { + dev_dbg(dev, "could not read %s for CS%d\n", + xp->prop, csindex); + continue; + } + + /* First check boolean props */ + if (xp->max == 1 && val) { + if (xp->slowreg) + slowcfg |= BIT(xp->shift); + else + fastcfg |= BIT(xp->shift); + dev_dbg(dev, "set %s flag\n", xp->prop); + continue; + } + + /* We're dealing with an u32 */ + if (val > xp->max) { + dev_err(dev, + "too high value for %s: %u, capped at %u\n", + xp->prop, val, xp->max); + val = xp->max; + } + if (xp->slowreg) + slowcfg |= (val << xp->shift); + else + fastcfg |= (val << xp->shift); + dev_dbg(dev, "set %s to %u\n", xp->prop, val); + } + + dev_info(dev, "CS%u: SLOW CFG 0x%08x, FAST CFG 0x%08x\n", + csindex, slowcfg, fastcfg); + + if (slowcfg) + writel(slowcfg, ebi2_xmem + csd->slow_cfg); + if (fastcfg) + writel(fastcfg, ebi2_xmem + csd->fast_cfg); +} + +static int qcom_ebi2_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct device_node *child; + struct device *dev = &pdev->dev; + struct resource *res; + void __iomem *ebi2_base; + void __iomem *ebi2_xmem; + struct clk *ebi2xclk; + struct clk *ebi2clk; + bool have_children = false; + u32 val; + int ret; + + ebi2xclk = devm_clk_get(dev, "ebi2x"); + if (IS_ERR(ebi2xclk)) + return PTR_ERR(ebi2xclk); + + ret = clk_prepare_enable(ebi2xclk); + if (ret) { + dev_err(dev, "could not enable EBI2X clk (%d)\n", ret); + return ret; + } + + ebi2clk = devm_clk_get(dev, "ebi2"); + if (IS_ERR(ebi2clk)) { + ret = PTR_ERR(ebi2clk); + goto err_disable_2x_clk; + } + + ret = clk_prepare_enable(ebi2clk); + if (ret) { + dev_err(dev, "could not enable EBI2 clk\n"); + goto err_disable_2x_clk; + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + ebi2_base = devm_ioremap_resource(dev, res); + if (IS_ERR(ebi2_base)) { + ret = PTR_ERR(ebi2_base); + goto err_disable_clk; + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 1); + ebi2_xmem = devm_ioremap_resource(dev, res); + if (IS_ERR(ebi2_xmem)) { + ret = PTR_ERR(ebi2_xmem); + goto err_disable_clk; + } + + /* Allegedly this turns the power save mode off */ + writel(0UL, ebi2_xmem + EBI2_XMEM_CFG); + + /* Disable all chipselects */ + val = readl(ebi2_base); + val &= ~EBI2_CSN_MASK; + writel(val, ebi2_base); + + /* Walk over the child nodes and see what chipselects we use */ + for_each_available_child_of_node(np, child) { + u32 csindex; + + /* Figure out the chipselect */ + ret = of_property_read_u32(child, "reg", &csindex); + if (ret) + return ret; + + if (csindex > 5) { + dev_err(dev, + "invalid chipselect %u, we only support 0-5\n", + csindex); + continue; + } + + qcom_ebi2_setup_chipselect(child, + dev, + ebi2_base, + ebi2_xmem, + csindex); + + /* We have at least one child */ + have_children = true; + } + + if (have_children) + return of_platform_default_populate(np, NULL, dev); + return 0; + +err_disable_clk: + clk_disable_unprepare(ebi2clk); +err_disable_2x_clk: + clk_disable_unprepare(ebi2xclk); + + return ret; +} + +static const struct of_device_id qcom_ebi2_of_match[] = { + { .compatible = "qcom,msm8660-ebi2", }, + { .compatible = "qcom,apq8060-ebi2", }, + { } +}; + +static struct platform_driver qcom_ebi2_driver = { + .probe = qcom_ebi2_probe, + .driver = { + .name = "qcom-ebi2", + .of_match_table = qcom_ebi2_of_match, + }, +}; +module_platform_driver(qcom_ebi2_driver); +MODULE_AUTHOR("Linus Walleij "); +MODULE_DESCRIPTION("Qualcomm EBI2 driver"); +MODULE_LICENSE("GPL");