From nobody Sat Feb 7 07:09:50 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 16CB833F8DA; Wed, 28 Jan 2026 12:25:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769603148; cv=none; b=YV17Jkdjeu/AbMDZI5VOhiCzj/7wITFibY2P8OHi9QZHUxmarZ/orBrZMgC2L148MpvzmC318cE5rWhsMz8OcAxu4cNyHV/FqHRLyL+e+1LPuFKKut+1VC5mduLPGTK0zJFxH64dXjjB7y1qzWBlhYZD/w11HBopDykDD4/G/C4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769603148; c=relaxed/simple; bh=m4Bu2xjNxMaziu7cHr/9vWIkSqxp2HE82nWmIg/qftM=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=OytoNLC8pBIAtGXSwcUe0n04OATGxkJjdg2wpY+f5NDKXehPbSr7J09gmB2dGl1NVS5GdkTCRdMX4lwUfmZD15MsBiC72rZSxAlsH+Ihl3eUDierTSu3lBB/2XghqxWQpr3PDYInEjXE4E2w4ZXN9XHSDsYThpBU96UqoORFKH8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=eXZQjkZ3; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="eXZQjkZ3" Received: by smtp.kernel.org (Postfix) with ESMTPS id C61DBC19422; Wed, 28 Jan 2026 12:25:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769603147; bh=m4Bu2xjNxMaziu7cHr/9vWIkSqxp2HE82nWmIg/qftM=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=eXZQjkZ36is5OxEy5IjErWrdHlrYizgtzRB1hqFT3QDjio8ZYsELBpunp84yfGmCn APArHPYiirCSuLjlDnMQdLlI0fz9JrSOsEe02GdwXWmvBSwcWlZYSIuOxYO3UBcuwv AoSA0XzP606IjM8lwKcW6U6Zz8Jvu8Ifo4cGhNMrdKm6Abf9AJDYRhH1fM+hDaGaLW B2+bJBuXtLR0nNgQYWCWSJE2otjFOit+kGEwR266uRWLxN/qwgVA6bXH1h/i+XmwS8 V3fs+PczXu5R0kDRvh01DwgCT6aJS8+fHYgceisJRh2qGxKbA8zUcRUWqRyHAp9kWs QZY8LvBOCf+kg== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id B865AD25B4E; Wed, 28 Jan 2026 12:25:47 +0000 (UTC) From: Ben Zong-You Xie via B4 Relay Date: Wed, 28 Jan 2026 20:25:45 +0800 Subject: [PATCH v3 2/4] i2c: add Andes I2C driver support Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260128-atciic100-v3-2-8c002fcc2bb4@andestech.com> References: <20260128-atciic100-v3-0-8c002fcc2bb4@andestech.com> In-Reply-To: <20260128-atciic100-v3-0-8c002fcc2bb4@andestech.com> To: Andi Shyti , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti Cc: linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Ben Zong-You Xie X-Mailer: b4 0.15-dev-47773 X-Developer-Signature: v=1; a=ed25519-sha256; t=1769603146; l=11439; i=ben717@andestech.com; s=20260120; h=from:subject:message-id; bh=JJvoU5xm6NYwGRCQSVZcQTCsnH+d2KxcC6DNdPLV+u8=; b=PSGQRohQrPW9usQgbqK4XxrszaN6tJ7BK9AUzMjsCrnqaIYAy1lQhW60yh5ftHCvDxNbL7lnj W6dLmmMLgTVBzF+RvBNtjxyjlwjDvqZb0+ZSQ8Y4iM6g4K7HqXax6+s X-Developer-Key: i=ben717@andestech.com; a=ed25519; pk=nb8L7zQKGJpYk0yvrYKjViOZ34A36g1ZIsCmCsP518s= X-Endpoint-Received: by B4 Relay for ben717@andestech.com/20260120 with auth_id=610 X-Original-From: Ben Zong-You Xie Reply-To: ben717@andestech.com From: Ben Zong-You Xie Add support for Andes I2C driver. Andes I2C can act as either a controller or a target, depending on the control register settings. Now, we only support controller mode. Signed-off-by: Ben Zong-You Xie --- drivers/i2c/busses/Kconfig | 10 ++ drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-andes.c | 341 +++++++++++++++++++++++++++++++++++++= ++++ 3 files changed, 352 insertions(+) diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index e11d50750e63..8b9dbc25af8b 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -446,6 +446,16 @@ config I2C_AT91_SLAVE_EXPERIMENTAL - There are some mismatches with a SAMA5D4 as slave and a SAMA5D2 as master. =20 +config I2C_ANDES + tristate "Andes I2C Controller" + depends on ARCH_ANDES || COMPILE_TEST + help + If you say yes to this option, support will be included for the + Andes I2C controller. + + This support is also available as a module. If so, the module + will be called i2c-andes. + config I2C_AU1550 tristate "Au1550/Au1200/Au1300 SMBus interface" depends on MIPS_ALCHEMY diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 547123ab351f..89d85d10f8d2 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -41,6 +41,7 @@ obj-$(CONFIG_I2C_ASPEED) +=3D i2c-aspeed.o obj-$(CONFIG_I2C_AT91) +=3D i2c-at91.o i2c-at91-y :=3D i2c-at91-core.o i2c-at91-master.o i2c-at91-$(CONFIG_I2C_AT91_SLAVE_EXPERIMENTAL) +=3D i2c-at91-slave.o +obj-$(CONFIG_I2C_ANDES) +=3D i2c-andes.o obj-$(CONFIG_I2C_AU1550) +=3D i2c-au1550.o obj-$(CONFIG_I2C_AXXIA) +=3D i2c-axxia.o obj-$(CONFIG_I2C_BCM2835) +=3D i2c-bcm2835.o diff --git a/drivers/i2c/busses/i2c-andes.c b/drivers/i2c/busses/i2c-andes.c new file mode 100644 index 000000000000..5f135d8c9b13 --- /dev/null +++ b/drivers/i2c/busses/i2c-andes.c @@ -0,0 +1,341 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Driver for Andes I2C controller, used in Andes AE350 platform and QiLai= SoC + * + * Copyright (C) 2026 Andes Technology Corporation. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#define ANDES_I2C_ID_REG 0x0 +#define ANDES_I2C_ID_MASK GENMASK(31, 8) +#define ANDES_I2C_ID 0x020210 + +#define ANDES_I2C_CFG_REG 0x10 +#define ANDES_I2C_CFG_FIFOSIZE GENMASK(1, 0) + +#define ANDES_I2C_INTEN_REG 0x14 +#define ANDES_I2C_INTEN_FIFO_EMPTY BIT(0) +#define ANDES_I2C_INTEN_FIFO_FULL BIT(1) +#define ANDES_I2C_INTEN_CMPL BIT(9) + +#define ANDES_I2C_STATUS_REG 0x18 +#define ANDES_I2C_STATUS_FIFO_EMPTY BIT(0) +#define ANDES_I2C_STATUS_FIFO_FULL BIT(1) +#define ANDES_I2C_STATUS_ADDR_HIT BIT(3) +#define ANDES_I2C_STATUS_CMPL BIT(9) +#define ANDES_I2C_STATUS_W1C GENMASK(9, 3) + +#define ANDES_I2C_ADDR_REG 0x1C + +#define ANDES_I2C_DATA_REG 0x20 + +#define ANDES_I2C_CTRL_REG 0x24 +#define ANDES_I2C_CTRL_DATA_CNT GENMASK(7, 0) +#define ANDES_I2C_CTRL_DIR BIT(8) +#define ANDES_I2C_CTRL_PHASE GENMASK(12, 9) + +#define ANDES_I2C_CMD_REG 0x28 +#define ANDES_I2C_CMD_ACTION GENMASK(2, 0) +#define ANDES_I2C_CMD_TRANS BIT(0) + +#define ANDES_I2C_SETUP_REG 0x2C +#define ANDES_I2C_SETUP_IICEN BIT(0) +#define ANDES_I2C_SETUP_REQ BIT(2) + +#define ANDES_I2C_TPM_REG 0x30 + +#define ANDES_I2C_TIMEOUT_US 400000 +#define ANDES_I2C_TIMEOUT usecs_to_jiffies(ANDES_I2C_TIMEOUT_US) + +#define ANDES_I2C_MAX_DATA_LEN 256 + +struct andes_i2c { + struct i2c_adapter adap; + struct completion completion; + spinlock_t lock; + struct regmap *map; + u8 *buf; + unsigned int fifo_size; + int irq; + u16 buf_len; + bool addr_hit; + bool xfer_done; +}; + +static const struct regmap_config andes_i2c_regmap_config =3D { + .name =3D "andes_i2c", + .reg_bits =3D 32, + .reg_stride =3D 4, + .val_bits =3D 32, + .pad_bits =3D 0, + .max_register =3D ANDES_I2C_TPM_REG, + .cache_type =3D REGCACHE_NONE, +}; + +static void andes_i2c_xfer_common(struct andes_i2c *i2c, u32 status) +{ + unsigned long flags; + unsigned int fsize =3D i2c->fifo_size; + unsigned int val; + + spin_lock_irqsave(&i2c->lock, flags); + if (status & ANDES_I2C_STATUS_FIFO_EMPTY) { + /* Disable the FIFO empty interrupt for the last write */ + if (i2c->buf_len <=3D fsize) { + fsize =3D i2c->buf_len; + regmap_clear_bits(i2c->map, ANDES_I2C_INTEN_REG, + ANDES_I2C_INTEN_FIFO_EMPTY); + } + + while (fsize--) { + val =3D *i2c->buf++; + regmap_write(i2c->map, ANDES_I2C_DATA_REG, val); + i2c->buf_len--; + } + } else if (status & ANDES_I2C_STATUS_FIFO_FULL) { + while (fsize--) { + regmap_read(i2c->map, ANDES_I2C_DATA_REG, &val); + *i2c->buf++ =3D (u8)val; + i2c->buf_len--; + } + } + + if (status & ANDES_I2C_STATUS_CMPL) { + i2c->xfer_done =3D true; + if (status & ANDES_I2C_STATUS_ADDR_HIT) + i2c->addr_hit =3D true; + + /* Write 1 to clear the status */ + regmap_set_bits(i2c->map, ANDES_I2C_STATUS_REG, + ANDES_I2C_STATUS_W1C); + + /* For the last read, retrieve all remaining data in FIFO. */ + while (i2c->buf_len > 0) { + regmap_read(i2c->map, ANDES_I2C_DATA_REG, &val); + *i2c->buf++ =3D (u8)val; + i2c->buf_len--; + } + } + + spin_unlock_irqrestore(&i2c->lock, flags); +} + +static irqreturn_t andes_i2c_irq_handler(int irq, void *data) +{ + struct andes_i2c *i2c =3D data; + u32 i2c_status; + + regmap_read(i2c->map, ANDES_I2C_STATUS_REG, &i2c_status); + andes_i2c_xfer_common(i2c, i2c_status); + if (i2c->xfer_done) + complete(&i2c->completion); + + return IRQ_HANDLED; +} + +static int andes_i2c_xfer_wait(struct andes_i2c *i2c, struct i2c_msg *msg) +{ + unsigned int mask; + unsigned int i2c_ctrl; + + /* + * Set the data count. If there are 256 bytes to be transmitted, write + * zero to the data count field. + */ + regmap_update_bits(i2c->map, ANDES_I2C_CTRL_REG, + ANDES_I2C_CTRL_DATA_CNT, + FIELD_PREP(ANDES_I2C_CTRL_DATA_CNT, i2c->buf_len)); + + regmap_set_bits(i2c->map, ANDES_I2C_CTRL_REG, ANDES_I2C_CTRL_PHASE); + if (msg->flags & I2C_M_RD) + regmap_set_bits(i2c->map, ANDES_I2C_CTRL_REG, + ANDES_I2C_CTRL_DIR); + else + regmap_clear_bits(i2c->map, ANDES_I2C_CTRL_REG, + ANDES_I2C_CTRL_DIR); + + regmap_write(i2c->map, ANDES_I2C_ADDR_REG, msg->addr); + + if (i2c->irq >=3D 0) { + mask =3D ANDES_I2C_INTEN_CMPL; + mask |=3D (msg->flags & I2C_M_RD) ? ANDES_I2C_INTEN_FIFO_FULL + : ANDES_I2C_INTEN_FIFO_EMPTY; + regmap_set_bits(i2c->map, ANDES_I2C_INTEN_REG, mask); + } + + regmap_set_bits(i2c->map, ANDES_I2C_CMD_REG, ANDES_I2C_CMD_TRANS); + if (i2c->irq >=3D 0) { + unsigned long time_left; + + time_left =3D wait_for_completion_timeout(&i2c->completion, + ANDES_I2C_TIMEOUT); + if (!time_left) + return -ETIMEDOUT; + + if (!i2c->addr_hit) + return -ENXIO; + + regmap_write(i2c->map, ANDES_I2C_INTEN_REG, 0); + reinit_completion(&i2c->completion); + } else { + unsigned int val; + int ret; + + mask =3D ANDES_I2C_STATUS_CMPL; + mask |=3D (msg->flags & I2C_M_RD) ? ANDES_I2C_STATUS_FIFO_FULL + : ANDES_I2C_STATUS_FIFO_EMPTY; + while (!i2c->xfer_done) { + ret =3D regmap_read_poll_timeout(i2c->map, + ANDES_I2C_STATUS_REG, + val, val & mask, 2000, + ANDES_I2C_TIMEOUT_US); + if (ret) + return ret; + + andes_i2c_xfer_common(i2c, val); + } + + if (!i2c->addr_hit) + return -ENXIO; + } + + /* Check if all data is successfully transmitted */ + regmap_read(i2c->map, ANDES_I2C_CTRL_REG, &i2c_ctrl); + if (FIELD_GET(ANDES_I2C_CTRL_DATA_CNT, i2c_ctrl)) + return -EIO; + + return 0; +} + +static int andes_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msg, + int num) +{ + int i; + struct i2c_msg *m; + struct andes_i2c *i2c =3D i2c_get_adapdata(adap); + int ret; + + for (i =3D 0; i < num; i++) { + m =3D &msg[i]; + i2c->addr_hit =3D false; + i2c->buf =3D m->buf; + i2c->buf_len =3D m->len; + i2c->xfer_done =3D false; + ret =3D andes_i2c_xfer_wait(i2c, m); + if (ret < 0) + return ret; + } + + return num; +} + +static u32 andes_i2c_func(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; +} + +static struct i2c_algorithm andes_i2c_algo =3D { + .xfer =3D andes_i2c_xfer, + .functionality =3D andes_i2c_func, +}; + +static const struct i2c_adapter_quirks andes_i2c_quirks =3D { + .flags =3D I2C_AQ_NO_ZERO_LEN, + .max_write_len =3D ANDES_I2C_MAX_DATA_LEN, + .max_read_len =3D ANDES_I2C_MAX_DATA_LEN, +}; + +static int andes_i2c_probe(struct platform_device *pdev) +{ + struct device *dev =3D &pdev->dev; + struct andes_i2c *i2c; + void __iomem *reg_base; + u32 i2c_id; + int ret; + struct i2c_adapter *adap; + + i2c =3D devm_kzalloc(dev, sizeof(*i2c), GFP_KERNEL); + if (!i2c) + return -ENOMEM; + + reg_base =3D devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(reg_base)) + return dev_err_probe(dev, PTR_ERR(reg_base), + "failed to map I/O space\n"); + + i2c->map =3D devm_regmap_init_mmio(dev, reg_base, + &andes_i2c_regmap_config); + if (IS_ERR(i2c->map)) + return dev_err_probe(dev, PTR_ERR(i2c->map), + "failed to initialize regmap\n"); + + regmap_read(i2c->map, ANDES_I2C_ID_REG, &i2c_id); + if (FIELD_GET(ANDES_I2C_ID_MASK, i2c_id) !=3D ANDES_I2C_ID) + return dev_err_probe(dev, -ENODEV, "unmatched hardware ID 0x%x\n", + i2c_id); + + i2c->irq =3D platform_get_irq(pdev, 0); + if (i2c->irq >=3D 0) { + ret =3D devm_request_irq(dev, i2c->irq, andes_i2c_irq_handler, 0, + dev_name(dev), i2c); + if (ret < 0) + return dev_err_probe(dev, ret, "unable to request IRQ %d\n", + i2c->irq); + } else { + dev_warn(dev, "no IRQ resource, falling back to poll mode\n"); + } + + spin_lock_init(&i2c->lock); + init_completion(&i2c->completion); + adap =3D &i2c->adap; + strscpy(adap->name, pdev->name, sizeof(adap->name)); + adap->algo =3D &andes_i2c_algo; + adap->class =3D I2C_CLASS_HWMON; + adap->dev.parent =3D dev; + adap->dev.of_node =3D dev->of_node; + adap->owner =3D THIS_MODULE; + adap->quirks =3D &andes_i2c_quirks; + adap->retries =3D 1; + adap->timeout =3D ANDES_I2C_TIMEOUT; + i2c_set_adapdata(adap, i2c); + platform_set_drvdata(pdev, i2c); + ret =3D devm_i2c_add_adapter(dev, adap); + if (ret) + return dev_err_probe(dev, ret, "failed to add adapter\n"); + + regmap_read(i2c->map, ANDES_I2C_CFG_REG, &i2c->fifo_size); + i2c->fifo_size =3D 2 << FIELD_GET(ANDES_I2C_CFG_FIFOSIZE, i2c->fifo_size); + + regmap_set_bits(i2c->map, ANDES_I2C_SETUP_REG, + ANDES_I2C_SETUP_IICEN | ANDES_I2C_SETUP_REQ); + return 0; +} + +static const struct of_device_id andes_i2c_of_match[] =3D { + { .compatible =3D "andestech,ae350-i2c" }, + { /* sentinel */ } +}; + +MODULE_DEVICE_TABLE(of, andes_i2c_of_match); + +static struct platform_driver andes_i2c_platform_driver =3D { + .driver =3D { + .name =3D "andes_i2c", + .of_match_table =3D andes_i2c_of_match, + }, + .probe =3D andes_i2c_probe, +}; + +module_platform_driver(andes_i2c_platform_driver); + +MODULE_AUTHOR("Ben Zong-You Xie "); +MODULE_DESCRIPTION("Andes I2C controller driver"); +MODULE_LICENSE("GPL"); --=20 2.34.1