From patchwork Tue Dec 13 08:26:57 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Binbin Zhou X-Patchwork-Id: 634030 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 AFE39C4332F for ; Tue, 13 Dec 2022 08:29:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234800AbiLMI3l (ORCPT ); Tue, 13 Dec 2022 03:29:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46284 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234801AbiLMI3N (ORCPT ); Tue, 13 Dec 2022 03:29:13 -0500 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 64A1EB4B4; Tue, 13 Dec 2022 00:27:09 -0800 (PST) Received: from loongson.cn (unknown [112.20.108.31]) by gateway (Coremail) with SMTP id _____8CxKek6N5hjtjQFAA--.8536S3; Tue, 13 Dec 2022 16:26:34 +0800 (CST) Received: from localhost.localdomain (unknown [112.20.108.31]) by localhost.localdomain (Coremail) with SMTP id AQAAf8BxoOI1N5hjkdEtAA--.45851S5; Tue, 13 Dec 2022 16:26:34 +0800 (CST) From: Binbin Zhou To: Wolfram Sang , Wolfram Sang , Andy Shevchenko , Mika Westerberg , linux-i2c@vger.kernel.org Cc: loongarch@lists.linux.dev, devicetree@vger.kernel.org, Huacai Chen , WANG Xuerui , Andy Shevchenko , Arnd Bergmann , Rob Herring , Krzysztof Kozlowski , Jianmin Lv , Binbin Zhou Subject: [PATCH V6 3/4] i2c: ls2x: Add driver for Loongson-2K/LS7A I2C controller Date: Tue, 13 Dec 2022 16:26:57 +0800 Message-Id: X-Mailer: git-send-email 2.31.1 In-Reply-To: References: MIME-Version: 1.0 X-CM-TRANSID: AQAAf8BxoOI1N5hjkdEtAA--.45851S5 X-CM-SenderInfo: p2kr3uplqex0o6or00hjvr0hdfq/ X-Coremail-Antispam: 1Uk129KBjvAXoW3CryfKrWfZFW3ur4Uuw13CFg_yoW8Jr13Xo WxXFsxXr48JFyUC3y0kr12qFW7Z39Y9ry3Kwn3Zr97ZFyjyF15tFyvkw15G3W2grW5KrWr urn3ta1fXF4fA34Un29KB7ZKAUJUUUU3529EdanIXcx71UUUUU7KY7ZEXasCq-sGcSsGvf J3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU0xBIdaVrnRJU UUBab4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2IYs7xG6rWj6s 0DM7CIcVAFz4kK6r1Y6r17M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Cr0_Gr1UM2 8EF7xvwVC2z280aVAFwI0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_Gr1j6F4U JwAaw2AFwI0_JF0_Jw1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqjxCEc2xF0cIa020Ex4 CE44I27wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jw0_WrylYx0E x4A2jsIE14v26r4j6F4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwCY1x 0262kKe7AKxVWUtVW8ZwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwCF I7km07C267AKxVWUAVWUtwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r 106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AK xVW5JVW7JwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7 xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r4j6F4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_ Gr1UYxBIdaVFxhVjvjDU0xZFpf9x07jr9NsUUUUU= Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org This I2C module is integrated into the Loongson-2K SoCs and Loongson LS7A bridge chip. Signed-off-by: Binbin Zhou --- drivers/i2c/busses/Kconfig | 11 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-ls2x.c | 376 ++++++++++++++++++++++++++++++++++ 3 files changed, 388 insertions(+) create mode 100644 drivers/i2c/busses/i2c-ls2x.c diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index e50f9603d189..908096a762ca 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -888,6 +888,17 @@ config I2C_OWL Say Y here if you want to use the I2C bus controller on the Actions Semiconductor Owl SoC's. +config I2C_LS2X + tristate "Loongson LS2X I2C adapter" + depends on MACH_LOONGSON64 || COMPILE_TEST + help + If you say yes to this option, support will be included for the + I2C interface on the Loongson-2K SoCs and Loongson LS7A bridge + chip. + + This driver can also be built as a module. If so, the module + will be called i2c-ls2x. + config I2C_PASEMI tristate "PA Semi SMBus interface" depends on PPC_PASEMI && PCI diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index e73cdb1d2b5a..df332ec3c489 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -86,6 +86,7 @@ obj-$(CONFIG_I2C_MV64XXX) += i2c-mv64xxx.o obj-$(CONFIG_I2C_MXS) += i2c-mxs.o obj-$(CONFIG_I2C_NOMADIK) += i2c-nomadik.o obj-$(CONFIG_I2C_NPCM) += i2c-npcm7xx.o +obj-$(CONFIG_I2C_LS2X) += i2c-ls2x.o obj-$(CONFIG_I2C_OCORES) += i2c-ocores.o obj-$(CONFIG_I2C_OMAP) += i2c-omap.o obj-$(CONFIG_I2C_OWL) += i2c-owl.o diff --git a/drivers/i2c/busses/i2c-ls2x.c b/drivers/i2c/busses/i2c-ls2x.c new file mode 100644 index 000000000000..ed51001fa237 --- /dev/null +++ b/drivers/i2c/busses/i2c-ls2x.c @@ -0,0 +1,376 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Loongson-2K/Loongson LS7A I2C master mode driver + * + * Copyright (C) 2013 Loongson Technology Corporation Limited. + * Copyright (C) 2014-2017 Lemote, Inc. + * Copyright (C) 2018-2022 Loongson Technology Corporation Limited. + * + * Originally written by liushaozong + * + * Rewritten for mainline by Binbin Zhou + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* I2C Registers */ +#define I2C_LS2X_PRER_LO 0x0 /* Freq Division Low Byte Register */ +#define I2C_LS2X_PRER_HI 0x1 /* Freq Division High Byte Register */ +#define I2C_LS2X_CTR 0x2 /* Control Register */ +#define I2C_LS2X_TXR 0x3 /* Transport Data Register */ +#define I2C_LS2X_RXR 0x3 /* Receive Data Register */ +#define I2C_LS2X_CR 0x4 /* Command Control Register */ +#define I2C_LS2X_SR 0x4 /* State Register */ + +/* Command Control Register Bit */ +#define LS2X_CR_START BIT(7) /* Start signal */ +#define LS2X_CR_STOP BIT(6) /* Stop signal */ +#define LS2X_CR_READ BIT(5) /* Read signal */ +#define LS2X_CR_WRITE BIT(4) /* Write signal */ +#define LS2X_CR_ACK BIT(3) /* Response signal */ +#define LS2X_CR_IACK BIT(0) /* Interrupt response signal */ + +/* State Register Bit */ +#define LS2X_SR_NOACK BIT(7) /* Receive NACK */ +#define LS2X_SR_BUSY BIT(6) /* Bus busy state */ +#define LS2X_SR_AL BIT(5) /* Arbitration lost */ +#define LS2X_SR_TIP BIT(1) /* Transmission state */ +#define LS2X_SR_IF BIT(0) /* Interrupt flag */ + +/* Control Register Bit */ +#define LS2X_CTR_EN BIT(7) /* 0: I2c frequency setting 1: Normal */ +#define LS2X_CTR_IEN BIT(6) /* Enable i2c interrupt */ +#define LS2X_CTR_MST BIT(5) /* 0: Slave mode 1: Master mode */ + +/* The PCLK clock frequency input from the LPB bus */ +#define LS2X_I2C_PCLK_FREQ (50 * HZ_PER_MHZ) + +/* The default bus frequency, which is an empirical value */ +#define LS2X_I2C_FREQ_STD (33 * HZ_PER_KHZ) + +struct ls2x_i2c_priv { + struct i2c_adapter adapter; + struct device *dev; + void __iomem *base; + struct i2c_timings i2c_t; + struct completion cmd_complete; +}; + +static int ls2x_i2c_xfer_byte(struct i2c_adapter *adap, u8 txdata, u8 *rxdatap) +{ + u8 rxdata; + unsigned long time_left; + struct ls2x_i2c_priv *priv = i2c_get_adapdata(adap); + + writeb(txdata, priv->base + I2C_LS2X_CR); + + time_left = wait_for_completion_timeout(&priv->cmd_complete, + adap->timeout); + if (!time_left) { + dev_err(&adap->dev, "transaction timeout\n"); + return -ETIMEDOUT; + } + + rxdata = readb(priv->base + I2C_LS2X_SR); + if (rxdatap) + *rxdatap = rxdata; + + return 0; +} + +static int ls2x_i2c_send_byte(struct i2c_adapter *adap, u8 txdata) +{ + int ret; + u8 rxdata; + + ret = ls2x_i2c_xfer_byte(adap, txdata, &rxdata); + if (ret) + return ret; + + if (rxdata & LS2X_SR_NOACK) + return -ENXIO; + + return 0; +} + +static int ls2x_i2c_stop(struct i2c_adapter *adap) +{ + int ret = ls2x_i2c_send_byte(adap, LS2X_CR_STOP); + + return (ret == -ENXIO) ? 0 : ret; +} + +static int ls2x_i2c_start(struct i2c_adapter *adap, struct i2c_msg *msgs) +{ + struct ls2x_i2c_priv *priv = i2c_get_adapdata(adap); + + reinit_completion(&priv->cmd_complete); + + writeb(i2c_8bit_addr_from_msg(msgs), priv->base + I2C_LS2X_TXR); + return ls2x_i2c_send_byte(adap, (LS2X_CR_START | LS2X_CR_WRITE)); +} + +static int ls2x_i2c_rx(struct i2c_adapter *adap, u8 *buf, u16 len) +{ + unsigned long time_left; + int cmd = LS2X_CR_READ; + struct ls2x_i2c_priv *priv = i2c_get_adapdata(adap); + + while (len--) { + writeb(cmd | (len ? 0 : LS2X_CR_ACK), priv->base + I2C_LS2X_CR); + + time_left = wait_for_completion_timeout(&priv->cmd_complete, + adap->timeout); + if (unlikely(!time_left)) { + dev_err(priv->dev, "transaction timeout\n"); + return -ETIMEDOUT; + } + + *buf++ = readb(priv->base + I2C_LS2X_RXR); + } + + return 0; +} + +static int ls2x_i2c_tx(struct i2c_adapter *adap, u8 *buf, u16 len) +{ + int ret; + struct ls2x_i2c_priv *priv = i2c_get_adapdata(adap); + + while (len--) { + writeb(*buf++, priv->base + I2C_LS2X_TXR); + + ret = ls2x_i2c_send_byte(adap, LS2X_CR_WRITE); + if (ret) + return ret; + } + + return 0; +} + +static int ls2x_i2c_xfer_one(struct i2c_adapter *adap, + struct i2c_msg *msg, bool stop) +{ + int ret; + bool is_read = msg->flags & I2C_M_RD; + + /* Contains steps to send start condition and address */ + ret = ls2x_i2c_start(adap, msg); + if (ret) + return ret; + + if (is_read) + ret = ls2x_i2c_rx(adap, msg->buf, msg->len); + else + ret = ls2x_i2c_tx(adap, msg->buf, msg->len); + + /* could not acquire bus. bail out without STOP */ + if (ret == -EAGAIN) + return ret; + + if (stop) + ret = ls2x_i2c_stop(adap); + + return ret; +} + +static int ls2x_i2c_master_xfer(struct i2c_adapter *adap, + struct i2c_msg *msgs, int num) +{ + int ret; + struct i2c_msg *msg, *emsg = msgs + num; + + for (msg = msgs; msg < emsg; msg++) { + /* Emit STOP if it is the last message or I2C_M_STOP is set */ + bool stop = (msg + 1 == emsg) || (msg->flags & I2C_M_STOP); + + ret = ls2x_i2c_xfer_one(adap, msg, stop); + if (ret) + return ret; + } + + return num; +} + +static unsigned int ls2x_i2c_func(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; +} + +static const struct i2c_algorithm ls2x_i2c_algo = { + .master_xfer = ls2x_i2c_master_xfer, + .functionality = ls2x_i2c_func, +}; + +/* + * Interrupt service routine. + * This gets called whenever an I2C interrupt occurs. + */ +static irqreturn_t ls2x_i2c_isr(int this_irq, void *dev_id) +{ + struct ls2x_i2c_priv *priv = dev_id; + + if (!(readb(priv->base + I2C_LS2X_SR) & LS2X_SR_IF)) + return IRQ_NONE; + + writeb(LS2X_CR_IACK, priv->base + I2C_LS2X_CR); + complete(&priv->cmd_complete); + return IRQ_HANDLED; +} + +/* + * The LS2X I2C controller supports standard mode and fast mode, + * so the maximum bus frequency is '400kHz'. + * The bus frequency is set to the empirical value of '33KHz' by default, + * but it can also be taken from ACPI or FDT for compatibility with more + * devices. + */ +static void ls2x_i2c_adjust_bus_speed(struct ls2x_i2c_priv *priv) +{ + struct i2c_timings *t = &priv->i2c_t; + u32 acpi_speed = i2c_acpi_find_bus_speed(priv->dev); + + i2c_parse_fw_timings(priv->dev, t, false); + + if (acpi_speed || t->bus_freq_hz) + t->bus_freq_hz = max(t->bus_freq_hz, acpi_speed); + else + t->bus_freq_hz = LS2X_I2C_FREQ_STD; + + /* Calculate and set LS2X I2C frequency */ + writel(LS2X_I2C_PCLK_FREQ / (5 * t->bus_freq_hz) - 1, + priv->base + I2C_LS2X_PRER_LO); +} + +static void ls2x_i2c_reginit(struct ls2x_i2c_priv *priv) +{ + u8 data; + + /* Enable operations about frequency divider register */ + data = readb(priv->base + I2C_LS2X_CTR); + writeb(data & ~LS2X_CTR_EN, priv->base + I2C_LS2X_CTR); + + ls2x_i2c_adjust_bus_speed(priv); + + /* Set to normal I2C operating mode and enable interrupts */ + data = readb(priv->base + I2C_LS2X_CTR); + writeb(data | LS2X_CTR_EN | LS2X_CTR_IEN | LS2X_CTR_MST, + priv->base + I2C_LS2X_CTR); +} + +static int ls2x_i2c_probe(struct platform_device *pdev) +{ + int r, irq; + struct i2c_adapter *adap; + struct ls2x_i2c_priv *priv; + struct device *dev = &pdev->dev; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->dev = dev; + platform_set_drvdata(pdev, priv); + init_completion(&priv->cmd_complete); + + /* Map hardware registers */ + priv->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(priv->base)) + return PTR_ERR(priv->base); + + ls2x_i2c_reginit(priv); + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + + r = devm_request_irq(dev, irq, ls2x_i2c_isr, + IRQF_SHARED, "ls2x-i2c", priv); + if (r < 0) + return dev_err_probe(dev, r, "Unable to request irq %d\n", irq); + + /* Add the i2c adapter */ + adap = &priv->adapter; + adap->nr = pdev->id; + adap->owner = THIS_MODULE; + adap->retries = 5; + adap->algo = &ls2x_i2c_algo; + adap->dev.parent = dev; + device_set_node(&adap->dev, dev_fwnode(dev)); + i2c_set_adapdata(adap, priv); + strscpy(adap->name, pdev->name, sizeof(adap->name)); + + return devm_i2c_add_adapter(dev, adap); +} + +static int ls2x_i2c_suspend(struct device *dev) +{ + struct ls2x_i2c_priv *priv = dev_get_drvdata(dev); + + /* Disable I2C interrupt */ + writeb(readb(priv->base + I2C_LS2X_CTR) & ~LS2X_CTR_IEN, + priv->base + I2C_LS2X_CTR); + + return 0; +} + +static int ls2x_i2c_resume(struct device *dev) +{ + struct ls2x_i2c_priv *priv = dev_get_drvdata(dev); + + ls2x_i2c_reginit(priv); + return 0; +} + +static DEFINE_RUNTIME_DEV_PM_OPS(ls2x_i2c_pm_ops, + ls2x_i2c_suspend, ls2x_i2c_resume, NULL); + +static const struct of_device_id ls2x_i2c_id_table[] = { + { .compatible = "loongson,ls2k-i2c" }, + { .compatible = "loongson,ls7a-i2c" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, ls2x_i2c_id_table); + +static const struct acpi_device_id ls2x_i2c_acpi_match[] = { + { "LOON0004" }, /* Loongson LS7A */ + { } +}; +MODULE_DEVICE_TABLE(acpi, ls2x_i2c_acpi_match); + +static struct platform_driver ls2x_i2c_driver = { + .probe = ls2x_i2c_probe, + .driver = { + .name = "ls2x-i2c", + .pm = pm_sleep_ptr(&ls2x_i2c_pm_ops), + .of_match_table = ls2x_i2c_id_table, + .acpi_match_table = ls2x_i2c_acpi_match, + }, +}; + +static int __init ls2x_i2c_init_driver(void) +{ + return platform_driver_register(&ls2x_i2c_driver); +} +subsys_initcall(ls2x_i2c_init_driver); + +static void __exit ls2x_i2c_exit_driver(void) +{ + platform_driver_unregister(&ls2x_i2c_driver); +} +module_exit(ls2x_i2c_exit_driver); + +MODULE_DESCRIPTION("Loongson LS2X I2C Bus driver"); +MODULE_AUTHOR("Loongson Technology Corporation Limited"); +MODULE_LICENSE("GPL");