Re: [PATCH 2/2] i3c: master: Add driver for MediaTek IP

From: Qii Wang <qii.wang@mediatek.com>
To: Boris Brezillon <boris.brezillon@collabora.com>
Cc: devicetree@vger.kernel.org, srv_heupstream@mediatek.com,
	bbrezillon@kernel.org, leilk.liu@mediatek.com,
	gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
	liguo.zhang@mediatek.com, linux-mediatek@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org, matthias.bgg@gmail.com,
	linux-i3c@lists.infradead.org, xinping.qian@mediatek.com
Subject: Re: [PATCH 2/2] i3c: master: Add driver for MediaTek IP
Date: Tue, 4 Jun 2019 20:26:40 +0800	[thread overview]
Message-ID: <1559651200.5871.2.camel@mhfsdcap03> (raw)
In-Reply-To: <20190604095858.38ed9a28@collabora.com>

On Tue, 2019-06-04 at 09:58 +0200, Boris Brezillon wrote:
> On Mon, 3 Jun 2019 11:51:03 +0800
> Qii Wang <qii.wang@mediatek.com> wrote:
> 
> 
> > +static int mtk_i3c_master_probe(struct platform_device *pdev)
> > +{
> > +	struct device *dev = &pdev->dev;
> > +	struct mtk_i3c_master *master;
> > +	struct resource *res;
> > +	int ret, irqnr;
> > +
> > +	master = devm_kzalloc(dev, sizeof(*master), GFP_KERNEL);
> > +	if (!master)
> > +		return -ENOMEM;
> > +
> > +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "main");
> > +	master->regs = devm_ioremap_resource(dev, res);
> > +	if (IS_ERR(master->regs))
> > +		return PTR_ERR(master->regs);
> > +
> > +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dma");
> > +	master->dma_regs = devm_ioremap_resource(dev, res);
> > +	if (IS_ERR(master->dma_regs))
> > +		return PTR_ERR(master->dma_regs);
> > +
> > +	irqnr = platform_get_irq(pdev, 0);
> > +	if (irqnr < 0)
> > +		return irqnr;
> > +
> > +	ret = devm_request_irq(dev, irqnr, mtk_i3c_master_irq,
> > +			       IRQF_TRIGGER_NONE, DRV_NAME, master);
> > +	if (ret < 0) {
> > +		dev_err(dev, "Request I3C IRQ %d fail\n", irqnr);
> > +		return ret;
> > +	}
> > +
> > +	ret = of_property_read_u32(pdev->dev.of_node, "clock-div",
> > +				   &master->clk_src_div);
> 
> You say in one comment that this clock divider is fixed in HW but might
> change on a per-SoC basis. If that's the case, you should get rid of
> this clock-div prop and attach the divider to the compatible (using an
> mtk_i3c_master_variant struct that contains a divider field).
> 

ok, I will attach the divider to the compatible.

> > +	if (ret < 0)
> > +		return -EINVAL;
> > +
> > +	spin_lock_init(&master->xferqueue.lock);
> > +	INIT_LIST_HEAD(&master->xferqueue.list);
> > +
> > +	if (dma_set_mask(dev, DMA_BIT_MASK(33))) {
> > +		dev_err(dev, "dma_set_mask return error.\n");
> > +		return -EINVAL;
> > +	}
> > +
> > +	master->clk_main = devm_clk_get(dev, "main");
> > +	if (IS_ERR(master->clk_main)) {
> > +		dev_err(dev, "cannot get main clock\n");
> > +		return PTR_ERR(master->clk_main);
> > +	}
> > +	master->clk_dma = devm_clk_get(dev, "dma");
> > +	if (IS_ERR(master->clk_dma)) {
> > +		dev_err(dev, "cannot get dma clock\n");
> > +		return PTR_ERR(master->clk_dma);
> > +	}
> > +
> > +	master->clk_arb = devm_clk_get_optional(dev, "arb");
> > +	if (IS_ERR(master->clk_arb))
> > +		return PTR_ERR(master->clk_arb);
> > +
> > +	ret = mtk_i3c_master_clock_enable(master);
> > +	if (ret) {
> > +		dev_err(dev, "clock enable failed!\n");
> > +		return ret;
> > +	}
> > +
> > +	master->dev = dev;
> > +	platform_set_drvdata(pdev, master);
> > +
> > +	ret = i3c_master_register(&master->mas_ctrler, dev,
> > +				  &mtk_i3c_master_ops, false);
> > +	if (ret) {
> > +		dev_err(dev, "Failed to add i3c bus to i3c core\n");
> > +		mtk_i3c_master_clock_disable(master);
> > +		return ret;
> > +	}
> > +
> > +	return 0;
> > +}

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