From mboxrd@z Thu Jan 1 00:00:00 1970 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 75D981AC450; Tue, 15 Oct 2024 08:08:37 +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=1728979717; cv=none; b=bYbE+nLtPHUxVjxt+IbzmneQPUQ5NIQgBpwvbboyh93MC2P9tFlGohbJeSXD/zV6KJjCFVK3YN/x9w6YufYu7x3O8yWgD3Qb0yi6ZKBazsW4nGrbaKb3ZuNX01ijEoWmNQv0aCXQ9gHPjLd3I2t8t8HNYVO1By5vbfsU5VgoPco= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728979717; c=relaxed/simple; bh=SxRcfy07HWRHVvCeOcAKYGN2gzLztYTiSILDxf0OiO8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=fFz82vAp1i/a6RUB7Y/whdNXuRHrT2Ezr4XdTGK2tA0G1xsA7s222patrdmHM00v9TEonRluAk5nej6fhNzCyk/HFsQqCuBE1IocZMyjkeMK7Kn5FtEa3WnBnRvNvM8jE6TmOczl+FFJ4snaVWlq/cRXto8qwsLxVPMQE80BYCk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IbXWbwiv; 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="IbXWbwiv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4489EC4CEC7; Tue, 15 Oct 2024 08:08:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728979716; bh=SxRcfy07HWRHVvCeOcAKYGN2gzLztYTiSILDxf0OiO8=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=IbXWbwivVtpNeRQ2NDb/NYnvIcI/FK2Vo2GDtnHNM3yfjMrNs6HbOhF4t2EebSeWv GFpL99uMYCbXVMBxjBEk1Xh1mS4PyQ28+hS+ANxRWi1PQwzezlDCKjtOYlTxclwfk/ BfjhSRM5P8IKsgdBmBEy8fqc12QwYDpnvoIN3cS0f0Oar9gYUx1Utj88rS/U8R51Vr fcFGPrLGq0cK7E5reRrMhP8Gq/nre0BHWOOUx2q77cmuhKmnqjRDwDnv86NUiToXsv l7bd6qGzyZyMXBJWkfw5SYJ5YpNNjR4zTB5Wyp+bCV41yD0OWp8nkX4b61DEdCFZTn +NjywQQ8uEdDw== Message-ID: Date: Tue, 15 Oct 2024 10:08:30 +0200 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1 2/2] i2c: spacemit: add support for SpacemiT K1 SoC To: Troy Mitchell , andi.shyti@kernel.org, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org Cc: linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org References: <20241015075134.1449458-1-TroyMitchell988@gmail.com> <20241015075134.1449458-3-TroyMitchell988@gmail.com> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 15/10/2024 09:51, Troy Mitchell wrote: > This patch introduces basic I2C support for the SpacemiT K1 SoC, > utilizing interrupts for transfers. > > The driver has been tested using i2c-tools on a Bananapi-F3 board, > and basic I2C read/write operations have been confirmed to work. > > Signed-off-by: Troy Mitchell > --- > drivers/i2c/busses/Kconfig | 18 + > drivers/i2c/busses/Makefile | 1 + > drivers/i2c/busses/i2c-k1.c | 694 ++++++++++++++++++++++++++++++++++++ > 3 files changed, 713 insertions(+) > create mode 100644 drivers/i2c/busses/i2c-k1.c > > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig > index 53f18b351f53..cfa5cda9c8d8 100644 > --- a/drivers/i2c/busses/Kconfig > +++ b/drivers/i2c/busses/Kconfig > @@ -800,6 +800,24 @@ config I2C_KEMPLD > This driver can also be built as a module. If so, the module > will be called i2c-kempld. > > +config I2C_K1 > + tristate "Spacemit K1 I2C adapter" > + depends on ARCH_SPACEMIT || COMPILE_TEST There is no such thing as ARCH_SPACEMIT. You never mentioned any dependency. > + help > + This option enables support for the I2C interface on the Spacemit K1 > + platform. > + > + If you enable this configuration, the kernel will include support for > + the I2C adapter specific to the Spacemit K1 platform. This driver ca > + be used to manage I2C bus transactions, which are necessary for > + interfacing with I2C peripherals such as sensors, EEPROMs, and other > + devices. > + > + This driver can also be compiled as a module. If you choose to build > + it as a module, the resulting kernel module will be named `i2c-k1`. > + Loading this module will enable the I2C functionality for the K1 > + platform dynamically, without requiring a rebuild of the kernel. > + > config I2C_LPC2K > tristate "I2C bus support for NXP LPC2K/LPC178x/18xx/43xx" > depends on OF && (ARCH_LPC18XX || COMPILE_TEST) > diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile > index ecc07c50f2a0..682e10435a7f 100644 > --- a/drivers/i2c/busses/Makefile > +++ b/drivers/i2c/busses/Makefile > @@ -78,6 +78,7 @@ obj-$(CONFIG_I2C_IOP3XX) += i2c-iop3xx.o > obj-$(CONFIG_I2C_JZ4780) += i2c-jz4780.o > obj-$(CONFIG_I2C_KEBA) += i2c-keba.o > obj-$(CONFIG_I2C_KEMPLD) += i2c-kempld.o > +obj-$(CONFIG_I2C_K1) += i2c-k1.o Are you sure you ordered it alphabetically? The same in Kconfig. > obj-$(CONFIG_I2C_LPC2K) += i2c-lpc2k.o > obj-$(CONFIG_I2C_LS2X) += i2c-ls2x.o > obj-$(CONFIG_I2C_MESON) += i2c-meson.o > diff --git a/drivers/i2c/busses/i2c-k1.c b/drivers/i2c/busses/i2c-k1.c > new file mode 100644 > index 000000000000..85053530d9b0 > --- /dev/null > +++ b/drivers/i2c/busses/i2c-k1.c > @@ -0,0 +1,694 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Copyright (C) 2024 Troy Mitchell > + */ ... > + > +static inline u32 spacemit_i2c_read_reg(struct spacemit_i2c_dev *i2c, int reg) > +{ > + return readl(i2c->base + reg); So basically short and obvious code like this: readl(i2c->base + reg); you replace with: spacemit_i2c_read_reg(i2c, reg) how is this helpful? > +} > + > +static inline void > +spacemit_i2c_write_reg(struct spacemit_i2c_dev *i2c, int reg, u32 val) > +{ > + writel(val, i2c->base + reg); > +} > + > +static void spacemit_i2c_enable(struct spacemit_i2c_dev *i2c) > +{ > + u32 val; > + > + val = spacemit_i2c_read_reg(i2c, ICR); > + spacemit_i2c_write_reg(i2c, ICR, val | CR_IUE); > +} > + > +static void spacemit_i2c_disable(struct spacemit_i2c_dev *i2c) > +{ > + u32 val; > + > + val = spacemit_i2c_read_reg(i2c, ICR); > + val &= ~CR_IUE; > + spacemit_i2c_write_reg(i2c, ICR, val); > +} > + > +static void spacemit_i2c_reset(struct spacemit_i2c_dev *i2c) > +{ > + spacemit_i2c_write_reg(i2c, ICR, CR_UR); > + udelay(5); > + spacemit_i2c_write_reg(i2c, ICR, 0); > +} > + > +static void spacemit_i2c_bus_reset(struct spacemit_i2c_dev *i2c) > +{ > + u32 status; > + > + /* if bus is locked, reset unit. 0: locked */ > + status = spacemit_i2c_read_reg(i2c, IBMR); > + > + if ((status & BMR_SDA) && (status & BMR_SCL)) > + return; > + > + spacemit_i2c_reset(i2c); > + usleep_range(10, 20); > + > + /* check scl status again */ > + status = spacemit_i2c_read_reg(i2c, IBMR); > + > + if (!(status & BMR_SCL)) > + dev_alert(i2c->dev, "unit reset failed\n"); dev_warn_ratelimited > +} > + > +static int spacemit_i2c_recover_bus_busy(struct spacemit_i2c_dev *i2c) > +{ > + int ret = 0; > + u32 val; > + ... > +static inline int spacemit_i2c_xfer_core(struct spacemit_i2c_dev *i2c) > +{ > + int ret = 0; > + > + spacemit_i2c_reset(i2c); > + > + spacemit_i2c_calc_timeout(i2c); > + > + spacemit_i2c_init(i2c); > + > + spacemit_i2c_enable(i2c); > + enable_irq(i2c->irq); > + > + /* i2c wait for bus busy */ > + ret = spacemit_i2c_recover_bus_busy(i2c); > + > + if (unlikely(ret)) > + return ret; > + > + ret = spacemit_i2c_xfer_msg(i2c); > + This coding style is poor... further on this in probe function. > + if (unlikely(ret < 0)) { > + dev_dbg(i2c->dev, "i2c transfer error\n"); > + /* timeout error should not be overridden, and the transfer > + * error will be confirmed by err handle function latter, > + * the reset should be invalid argument error. > + */ > + if (ret != -ETIMEDOUT) > + ret = -EINVAL; > + } > + > + return ret; > +} > + > +static int > +spacemit_i2c_xfer(struct i2c_adapter *adapt, struct i2c_msg msgs[], int num) > +{ > + struct spacemit_i2c_dev *i2c = i2c_get_adapdata(adapt); > + int ret; > + > + i2c->msgs = msgs; > + i2c->msg_num = num; > + > + ret = spacemit_i2c_xfer_core(i2c); > + > + if (likely(!ret)) > + spacemit_i2c_check_bus_release(i2c); > + > + disable_irq(i2c->irq); > + > + spacemit_i2c_disable(i2c); > + > + if (unlikely((ret == -ETIMEDOUT || ret == -EAGAIN))) > + dev_alert(i2c->dev, "i2c transfer failed, ret %d err 0x%x\n", > + ret, i2c->err); > + > + return ret < 0 ? ret : num; > +} > + > +static u32 spacemit_i2c_func(struct i2c_adapter *adap) > +{ > + return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK); > +} > + > +static const struct i2c_algorithm spacemit_i2c_algo = { > + .xfer = spacemit_i2c_xfer, > + .functionality = spacemit_i2c_func, > +}; > + > +static int spacemit_i2c_probe(struct platform_device *pdev) > +{ > + struct spacemit_i2c_dev *i2c; > + struct device_node *of_node = pdev->dev.of_node; > + struct clk *clk; > + int ret = 0; > + > + i2c = devm_kzalloc(&pdev->dev, > + sizeof(struct spacemit_i2c_dev), sizeof(*) and stop unnecessary wrapping. > + GFP_KERNEL); > + if (!i2c) > + return -ENOMEM; > + > + i2c->dev = &pdev->dev; > + > + i2c->base = devm_platform_ioremap_resource(pdev, 0); > + if (!i2c->base) { > + ret = PTR_ERR(i2c->base); Drop > + return dev_err_probe(&pdev->dev, ret, "failed to do ioremap"); Just use here PTR_ERR > + } > + > + i2c->irq = platform_get_irq(pdev, 0); > + if (i2c->irq < 0) { > + ret = i2c->irq; Drop, really useless. > + return dev_err_probe(&pdev->dev, ret, "failed to get irq resource"); > + } > + > + ret = devm_request_irq(i2c->dev, i2c->irq, > + spacemit_i2c_irq_handler, > + IRQF_NO_SUSPEND | IRQF_ONESHOT, > + dev_name(i2c->dev), i2c); > + There is never a blank line between call and it's condition check if() statement. > + if (ret) > + return dev_err_probe(&pdev->dev, ret, "failed to request irq"); > + > + disable_irq(i2c->irq); Why? > + > + clk = devm_clk_get_enabled(&pdev->dev, NULL); > + if (IS_ERR(clk)) { > + ret = PTR_ERR(clk); drop > + return dev_err_probe(&pdev->dev, ret, "failed to enable clock"); > + } > + > + i2c_set_adapdata(&i2c->adapt, i2c); > + i2c->adapt.owner = THIS_MODULE; > + i2c->adapt.algo = &spacemit_i2c_algo; > + i2c->adapt.dev.parent = i2c->dev; > + i2c->adapt.nr = pdev->id; > + > + i2c->adapt.dev.of_node = of_node; > + i2c->adapt.algo_data = i2c; > + > + strscpy(i2c->adapt.name, "spacemit-i2c-adapter", sizeof(i2c->adapt.name)); > + > + init_completion(&i2c->complete); > + > + ret = i2c_add_numbered_adapter(&i2c->adapt); > + Drop stray blank line > + if (ret) > + return dev_err_probe(&pdev->dev, ret, "failed to add i2c adapter"); > + > + platform_set_drvdata(pdev, i2c); > + > + return 0; > +} > + > +static void spacemit_i2c_remove(struct platform_device *pdev) > +{ > + struct spacemit_i2c_dev *i2c = platform_get_drvdata(pdev); > + > + i2c_del_adapter(&i2c->adapt); > +} > + > +static const struct of_device_id spacemit_i2c_dt_match[] = { > + { .compatible = "spacemit,k1-i2c", }, > + { /* sentinel */ } > +}; > +MODULE_DEVICE_TABLE(of, spacemit_i2c_dt_match); > + > +static struct platform_driver spacemit_i2c_driver = { > + .probe = spacemit_i2c_probe, > + .remove_new = spacemit_i2c_remove, > + .driver = { > + .name = "i2c-k1", > + .of_match_table = spacemit_i2c_dt_match, > + }, > +}; > +module_platform_driver(spacemit_i2c_driver); > + > +MODULE_LICENSE("GPL"); > +MODULE_DESCRIPTION("I2C bus driver for SpacemiT K1 SoC"); Best regards, Krzysztof