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Received: from mail.kernel.org ([198.145.29.99]) by casper.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kaTdB-0005vk-7C for linux-arm-kernel@lists.infradead.org; Thu, 05 Nov 2020 01:00:04 +0000 Received: from kernel.org (unknown [104.132.1.79]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EC2422072E; Thu, 5 Nov 2020 00:59:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604537997; bh=QcbyPWSRQulyeWOH3d6eP/j4FKXehRssL3e64gDdsZA=; h=In-Reply-To:References:Subject:From:Cc:To:Date:From; b=zxBt9tj9A2tvOxGhzZPWcy7rDagAZM01fC+6CoM7xH7miVFKWPIj3v3dHe9Rnoued wllq5VGdDQW8VQ8o91TKMw5uBrrtidvIb2nCK4EDMDWh6Ff7eULZWDITARNOQPnQAP YJcIvp5XJnLv5gUUOAClyU8NH4B/gIdHBw0mvJtM= MIME-Version: 1.0 In-Reply-To: <1604402306-5348-11-git-send-email-abel.vesa@nxp.com> References: <1604402306-5348-1-git-send-email-abel.vesa@nxp.com> <1604402306-5348-11-git-send-email-abel.vesa@nxp.com> Subject: Re: [PATCH v5 10/14] clk: imx: Add generic blk-ctl driver From: Stephen Boyd To: Abel Vesa , Adam Ford , Anson Huang , Dong Aisheng , Fabio Estevam , Jacky Bai , Lucas Stach , Marek Vasut , Mike Turquette , Peng Fan , Rob Herring , Sascha Hauer , Shawn Guo Date: Wed, 04 Nov 2020 16:59:55 -0800 Message-ID: <160453799538.3965362.16773121624590810076@swboyd.mtv.corp.google.com> User-Agent: alot/0.9.1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201105_010001_783299_C1BE56D0 X-CRM114-Status: GOOD ( 26.90 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devicetree@vger.kernel.org, Abel Vesa , Linux Kernel Mailing List , NXP Linux Team , linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Quoting Abel Vesa (2020-11-03 03:18:22) > diff --git a/drivers/clk/imx/clk-blk-ctl.c b/drivers/clk/imx/clk-blk-ctl.c > new file mode 100644 > index 00000000..9ac0ed0 > --- /dev/null > +++ b/drivers/clk/imx/clk-blk-ctl.c > @@ -0,0 +1,302 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Copyright 2020 NXP. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "clk.h" > +#include "clk-blk-ctl.h" > + > +struct imx_reset_hw { > + u32 offset; > + u32 shift; > + u32 mask; > + unsigned long asserted; > +}; > + > +struct imx_pm_safekeep_info { > + uint32_t *regs_values; > + uint32_t *regs_offsets; Please use u32, it's shorter and kernel style. > + uint32_t regs_num; > +}; > + > +struct imx_blk_ctl_drvdata { > + void __iomem *base; > + struct reset_controller_dev rcdev; > + struct imx_reset_hw *rst_hws; > + struct imx_pm_safekeep_info pm_info; > + > + spinlock_t lock; > +}; > + > +static void __maybe_unused imx_blk_ctl_read_write(struct device *dev, > + bool write) > +{ > + struct imx_blk_ctl_drvdata *drvdata = dev_get_drvdata(dev); > + struct imx_pm_safekeep_info *pm_info = &drvdata->pm_info; > + void __iomem *base = drvdata->base; > + int i; > + > + if (!pm_info->regs_num) > + return; > + > + for (i = 0; i < pm_info->regs_num; i++) { > + u32 offset = pm_info->regs_offsets[i]; > + > + if (write) > + writel(pm_info->regs_values[i], base + offset); > + else > + pm_info->regs_values[i] = readl(base + offset); > + } > + > +} > + > +static int __maybe_unused imx_blk_ctl_runtime_suspend(struct device *dev) > +{ > + imx_blk_ctl_read_write(dev, false); > + > + return 0; > +} > + > +static int __maybe_unused imx_blk_ctl_runtime_resume(struct device *dev) > +{ > + imx_blk_ctl_read_write(dev, true); > + > + return 0; > +} > + > +const struct dev_pm_ops imx_blk_ctl_pm_ops = { > + SET_RUNTIME_PM_OPS(imx_blk_ctl_runtime_suspend, > + imx_blk_ctl_runtime_resume, NULL) > + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, > + pm_runtime_force_resume) > +}; > +EXPORT_SYMBOL_GPL(imx_blk_ctl_pm_ops); > + > +static int imx_blk_ctl_reset_set(struct reset_controller_dev *rcdev, > + unsigned long id, bool assert) > +{ > + struct imx_blk_ctl_drvdata *drvdata = container_of(rcdev, > + struct imx_blk_ctl_drvdata, rcdev); > + unsigned int offset = drvdata->rst_hws[id].offset; > + unsigned int shift = drvdata->rst_hws[id].shift; > + unsigned int mask = drvdata->rst_hws[id].mask; > + void __iomem *reg_addr = drvdata->base + offset; > + unsigned long flags; > + u32 reg; > + > + if (!assert && !test_bit(1, &drvdata->rst_hws[id].asserted)) > + return -ENODEV; > + > + if (assert && !test_and_set_bit(1, &drvdata->rst_hws[id].asserted)) We are testing the same bit atomically, twice. At a quick glance this code looks broken. But then looking closer it's being multiplexed. Can we move these assert/!assert checks to the caller? It will make it easier to reason about. Is the atomic-ness of this code important? If not, it should use __test_bit() and __test_and_set_bit() because locking is being handled somewhere higher up. Furthermore, why are we using a per-reset bitmap to set one bit? Either combine them into one bitmap or have a simple bool please. > + pm_runtime_get_sync(rcdev->dev); > + > + spin_lock_irqsave(&drvdata->lock, flags); > + > + reg = readl(reg_addr); > + if (assert) > + writel(reg & ~(mask << shift), reg_addr); > + else > + writel(reg | (mask << shift), reg_addr); > + > + spin_unlock_irqrestore(&drvdata->lock, flags); > + > + if (!assert && test_and_clear_bit(1, &drvdata->rst_hws[id].asserted)) > + pm_runtime_put(rcdev->dev); > + Same comment here. > + return 0; > +} > + > +static int imx_blk_ctl_reset_assert(struct reset_controller_dev *rcdev, > + unsigned long id) > +{ > + return imx_blk_ctl_reset_set(rcdev, id, true); > +} > + > +static int imx_blk_ctl_reset_deassert(struct reset_controller_dev *rcdev, > + unsigned long id) > +{ > + return imx_blk_ctl_reset_set(rcdev, id, false); > +} > + > +static const struct reset_control_ops imx_blk_ctl_reset_ops = { > + .assert = imx_blk_ctl_reset_assert, > + .deassert = imx_blk_ctl_reset_deassert, > +}; > + > +static int imx_blk_ctl_register_reset_controller(struct device *dev) > +{ > + const struct imx_blk_ctl_dev_data *dev_data = of_device_get_match_data(dev); > + struct imx_blk_ctl_drvdata *drvdata = dev_get_drvdata(dev); > + int max = dev_data->resets_max; > + struct imx_reset_hw *hws; > + int i; > + > + spin_lock_init(&drvdata->lock); > + > + drvdata->rcdev.owner = THIS_MODULE; > + drvdata->rcdev.nr_resets = max; > + drvdata->rcdev.ops = &imx_blk_ctl_reset_ops; > + drvdata->rcdev.of_node = dev->of_node; > + drvdata->rcdev.dev = dev; > + > + drvdata->rst_hws = devm_kcalloc(dev, max, sizeof(struct imx_reset_hw), > + GFP_KERNEL); > + hws = drvdata->rst_hws; > + > + for (i = 0; i < dev_data->hws_num; i++) { > + struct imx_blk_ctl_hw *hw = &dev_data->hws[i]; > + > + if (hw->type != BLK_CTL_RESET) > + continue; > + > + hws[hw->id].offset = hw->offset; > + hws[hw->id].shift = hw->shift; > + hws[hw->id].mask = hw->mask; > + } > + > + return devm_reset_controller_register(dev, &drvdata->rcdev); > +} Nitpick: Add a newline here please > +static struct clk_hw *imx_blk_ctl_register_one_clock(struct device *dev, > + struct imx_blk_ctl_hw *hw) > +{ > + struct imx_blk_ctl_drvdata *drvdata = dev_get_drvdata(dev); > + void __iomem *base = drvdata->base; > + struct clk_hw *clk_hw = NULL; Is this necessary? Please add a default to the case if so and drop this assignment. But if all hw->type are covered in the case statement then this assignment can be dropped and nothing else. The compiler should tell us we forgot to handle a case. > + > + switch (hw->type) { > + case BLK_CTL_CLK_MUX: > + clk_hw = imx_dev_clk_hw_mux_flags(dev, hw->name, > + base + hw->offset, > + hw->shift, hw->width, > + hw->parents, > + hw->parents_count, > + hw->flags); > + break; > + case BLK_CTL_CLK_GATE: > + clk_hw = imx_dev_clk_hw_gate(dev, hw->name, hw->parents, > + base + hw->offset, hw->shift); > + break; > + case BLK_CTL_CLK_SHARED_GATE: > + clk_hw = imx_dev_clk_hw_gate_shared(dev, hw->name, > + hw->parents, > + base + hw->offset, > + hw->shift, > + hw->shared_count); > + break; > + case BLK_CTL_CLK_PLL14XX: > + clk_hw = imx_dev_clk_hw_pll14xx(dev, hw->name, hw->parents, > + base + hw->offset, hw->pll_tbl); > + break; > + }; > + > + return clk_hw; > +} > + > +static int imx_blk_ctl_register_clock_controller(struct device *dev) > +{ > + const struct imx_blk_ctl_dev_data *dev_data = of_device_get_match_data(dev); > + struct clk_hw_onecell_data *clk_hw_data; > + struct clk_hw **hws; > + int i; > + > + clk_hw_data = devm_kzalloc(dev, struct_size(clk_hw_data, hws, > + dev_data->hws_num), GFP_KERNEL); > + if (WARN_ON(!clk_hw_data)) We can drop the WARN_ON() call, slab allocations already print a stacktrace. > + return -ENOMEM; > + > + clk_hw_data->num = dev_data->clocks_max; > + hws = clk_hw_data->hws; > + > + for (i = 0; i < dev_data->hws_num; i++) { > + struct imx_blk_ctl_hw *hw = &dev_data->hws[i]; > + Add a comment like /* Resets aren't a clk */ > + if (hw->type == BLK_CTL_RESET) > + continue; > + > + hws[hw->id] = imx_blk_ctl_register_one_clock(dev, hw); > + } > + > + imx_check_clk_hws(hws, dev_data->clocks_max); > + > + return of_clk_add_hw_provider(dev->of_node, of_clk_hw_onecell_get, > + clk_hw_data); > +} > + > +static int imx_blk_ctl_init_runtime_pm_safekeeping(struct device *dev) > +{ > + const struct imx_blk_ctl_dev_data *dev_data = of_device_get_match_data(dev); > + struct imx_blk_ctl_drvdata *drvdata = dev_get_drvdata(dev); > + struct imx_pm_safekeep_info *pm_info = &drvdata->pm_info; > + u32 regs_num = dev_data->pm_runtime_saved_regs_num; > + const u32 *regs_offsets = dev_data->pm_runtime_saved_regs; > + > + if (!dev_data->pm_runtime_saved_regs_num) > + return 0; > + > + pm_info->regs_values = devm_kzalloc(dev, > + sizeof(u32) * regs_num, > + GFP_KERNEL); > + if (WARN_ON(IS_ERR(pm_info->regs_values))) Please drop WARN_ON > + return PTR_ERR(pm_info->regs_values); > + > + pm_info->regs_offsets = kmemdup(regs_offsets, > + regs_num * sizeof(u32), GFP_KERNEL); > + if (WARN_ON(IS_ERR(pm_info->regs_offsets))) Please drop WARN_ON > + return PTR_ERR(pm_info->regs_offsets); > + > + pm_info->regs_num = regs_num; > + > + return 0; > +} > + > +int imx_blk_ctl_register(struct platform_device *pdev) > +{ > + struct imx_blk_ctl_drvdata *drvdata; > + struct device *dev = &pdev->dev; > + int ret; > + > + drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL); > + if (WARN_ON(!drvdata)) Please drop WARN_ON > + return -ENOMEM; > + > + drvdata->base = devm_platform_ioremap_resource(pdev, 0); > + if (WARN_ON(IS_ERR(drvdata->base))) Please drop WARN_ON > + return PTR_ERR(drvdata->base); > + > + dev_set_drvdata(dev, drvdata); > + > + ret = imx_blk_ctl_init_runtime_pm_safekeeping(dev); > + if (ret) > + return ret; > + > + pm_runtime_get_noresume(dev); > + pm_runtime_set_active(dev); > + pm_runtime_enable(dev); > + > + ret = imx_blk_ctl_register_clock_controller(dev); > + if (ret) { > + pm_runtime_put(dev); > + return ret; > + } > + > + ret = imx_blk_ctl_register_reset_controller(dev); > + > + pm_runtime_put(dev); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(imx_blk_ctl_register); > diff --git a/drivers/clk/imx/clk-blk-ctl.h b/drivers/clk/imx/clk-blk-ctl.h > new file mode 100644 > index 00000000..3f14a47 > --- /dev/null > +++ b/drivers/clk/imx/clk-blk-ctl.h > @@ -0,0 +1,80 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +#ifndef __MACH_IMX_CLK_BLK_CTL_H > +#define __MACH_IMX_CLK_BLK_CTL_H > + > +enum imx_blk_ctl_hw_type { > + BLK_CTL_CLK_MUX, > + BLK_CTL_CLK_GATE, > + BLK_CTL_CLK_SHARED_GATE, > + BLK_CTL_CLK_PLL14XX, > + BLK_CTL_RESET, > +}; > + > +struct imx_blk_ctl_hw { > + int type; > + char *name; > + u32 offset; > + u32 shift; > + u32 mask; > + u32 width; > + u32 flags; > + u32 id; > + const void *parents; > + u32 parents_count; > + int *shared_count; > + const struct imx_pll14xx_clk *pll_tbl; Please forward declare pointer types. > +}; > + > +struct imx_blk_ctl_dev_data { > + struct imx_blk_ctl_hw *hws; Please forward declare pointer types. > + u32 hws_num; > + > + u32 clocks_max; > + u32 resets_max; > + > + u32 pm_runtime_saved_regs_num; > + u32 pm_runtime_saved_regs[]; > +}; > + > +#define IMX_BLK_CTL(_type, _name, _id, _offset, _shift, _width, _mask, _parents, _parents_count, _flags, sh_count, _pll_tbl) \ > + { \ > + .type = _type, \ > + .name = _name, \ > + .id = _id, \ > + .offset = _offset, \ > + .shift = _shift, \ > + .width = _width, \ > + .mask = _mask, \ > + .parents = _parents, \ > + .parents_count = _parents_count, \ > + .flags = _flags, \ > + .shared_count = sh_count, \ > + .pll_tbl = _pll_tbl, \ > + } > + > +#define IMX_BLK_CTL_CLK_MUX(_name, _id, _offset, _shift, _width, _parents) \ > + IMX_BLK_CTL(BLK_CTL_CLK_MUX, _name, _id, _offset, _shift, _width, 0, _parents, ARRAY_SIZE(_parents), 0, NULL, NULL) > + > +#define IMX_BLK_CTL_CLK_MUX_FLAGS(_name, _id, _offset, _shift, _width, _parents, _flags) \ > + IMX_BLK_CTL(BLK_CTL_CLK_MUX, _name, _id, _offset, _shift, _width, 0, _parents, ARRAY_SIZE(_parents), _flags, NULL, NULL) > + > +#define IMX_BLK_CTL_CLK_GATE(_name, _id, _offset, _shift, _parents) \ > + IMX_BLK_CTL(BLK_CTL_CLK_GATE, _name, _id, _offset, _shift, 1, 0, _parents, 1, 0, NULL, NULL) > + > +#define IMX_BLK_CTL_CLK_SHARED_GATE(_name, _id, _offset, _shift, _parents, sh_count) \ > + IMX_BLK_CTL(BLK_CTL_CLK_SHARED_GATE, _name, _id, _offset, _shift, 1, 0, _parents, 1, 0, sh_count, NULL) > + > +#define IMX_BLK_CTL_CLK_PLL14XX(_name, _id, _offset, _parents, _pll_tbl) \ > + IMX_BLK_CTL(BLK_CTL_CLK_PLL14XX, _name, _id, _offset, 0, 0, 0, _parents, 1, 0, NULL, _pll_tbl) > + > +#define IMX_BLK_CTL_RESET(_id, _offset, _shift) \ > + IMX_BLK_CTL(BLK_CTL_RESET, NULL, _id, _offset, _shift, 0, 1, NULL, 0, 0, NULL, NULL) > + > +#define IMX_BLK_CTL_RESET_MASK(_id, _offset, _shift, mask) \ > + IMX_BLK_CTL(BLK_CTL_RESET, NULL, _id, _offset, _shift, 0, mask, NULL, 0, 0, NULL, NULL) > + > +extern const struct dev_pm_ops imx_blk_ctl_pm_ops; > + > +int imx_blk_ctl_register(struct platform_device *pdev); Please forward declare pointer types. > + > +#endif > -- > 2.7.4 > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel