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Message-ID: <4e10a6ed7a1707f093a8947237faea075842d6e5.camel@microchip.com>
Date: Wed, 24 Aug 2022 13:48:39 +0000
From: <Tharunkumar.Pasumarthi@...rochip.com>
To: <linux-i2c@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<krzysztof.kozlowski@...aro.org>, <wsa@...nel.org>
CC: <UNGLinuxDriver@...rochip.com>,
<andriy.shevchenko@...ux.intel.com>, <robh@...nel.org>,
<jsd@...ihalf.com>, <olof@...om.net>,
<jarkko.nikula@...ux.intel.com>, <semen.protsenko@...aro.org>,
<sven@...npeter.dev>, <rafal@...ecki.pl>, <arnd@...db.de>
Subject: Re: [PATCH RFC i2c-master] i2c: microchip: pci1xxxx: Add driver for
I2C host controller in multifunction endpoint of pci1xxxx switch
On Tue, 2022-08-23 at 13:31 +0300, Krzysztof Kozlowski wrote:
>
> On 23/08/2022 17:56, Tharun Kumar P wrote:
> > Microchip PCI1XXXX is an unmanaged PCIe3.1a Switch for Consumer,
> > Industrial and Automotive applications. This switch has multiple
> > downstream ports. In one of the Switch's Downstream port, there
> > is a multifunction endpoint for peripherals which includes an I2C
> > host controller. The I2C function in the endpoint operates at 100KHz,
> > 400KHz and 1 MHz and has buffer depth of 128 bytes.
> > This patch provides the I2C controller driver for the I2C endpoint
> > of the switch.
>
> (...)
>
> > +static int pci1xxxx_i2c_suspend(struct device *dev)
> > +{
> > + struct pci1xxxx_i2c *i2c = dev_get_drvdata(dev);
> > + struct pci_dev *pdev = to_pci_dev(dev);
> > + u32 regval;
> > +
> > + i2c_mark_adapter_suspended(&i2c->adap);
> > +
> > + while ((i2c->i2c_xfer_in_progress))
> > + msleep(20);
> > +
> > + pci1xxxx_i2c_config_high_level_intr(i2c,
> > + SMBALERT_WAKE_INTR_MASK,
> > + true);
> > +
> > + /*Enable the PERST_DIS bit to mask the PERST from
> > + *resetting the core regs
> > + */
>
> Use Linux coding style comments. Everywhere...
Okay. I will fix Linux coding style for comments throughout the file in upcoming
patch.
> (...)
>
> > +
> > +static int pci1xxxx_i2c_probe_pci(struct pci_dev *pdev,
> > + const struct pci_device_id *ent)
> > +{
> > + struct pci1xxxx_i2c *i2c;
> > + int ret;
> > +
> > + i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
> > + if (!i2c)
> > + return -ENOMEM;
> > +
> > + pci_set_drvdata(pdev, i2c);
> > +
> > + i2c->i2c_xfer_in_progress = false;
> > +
> > + ret = pcim_enable_device(pdev);
> > + if (ret)
> > + return ret;
> > +
> > + pci_set_master(pdev);
> > +
> > + /* we are getting the base address of the SMB core. SMB core uses
> > + * BAR0 and 32K is the size here pci_resource_len returns 32K by
> > + * reading BAR0
> > + */
> > +
> > + ret = pcim_iomap_regions(pdev, BIT(0), pci_name(pdev));
> > + if (ret < 0)
> > + return -ENOMEM;
> > +
> > + i2c->i2c_base = pcim_iomap_table(pdev)[0];
> > +
> > + init_completion(&i2c->i2c_xfer_done);
> > +
> > + pci1xxxx_i2c_init(i2c);
> > +
> > + dev_info(&pdev->dev, "i2c clock freq: %d\n", i2c->freq);
>
> That's not a helpful print. Don't pollute dmesg.
I will remove this print
> > +
> > + ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES);
> > + if (ret < 0)
> > + return ret;
> > +
> > + /*Register the isr. we are not using any isr flags here.*/
>
> Use Linux coding style comments. Everywhere...
Okay
> > + ret = devm_request_irq(&pdev->dev, pci_irq_vector(pdev, 0),
> > + pci1xxxx_i2c_isr, PCI1XXXX_IRQ_FLAGS,
> > + pci_name(pdev), i2c);
> > + if (ret)
> > + goto err_free_region;
> > +
> > + i2c->adap = pci1xxxx_i2c_ops;
> > + i2c->adap.class = I2C_CLASS_SPD;
> > + i2c->adap.dev.parent = &pdev->dev;
> > +
> > + snprintf(i2c->adap.name, sizeof(i2c->adap.name),
> > + "MCHP PCI1xxxx i2c adapter at %s", pci_name(pdev));
> > +
> > + i2c_set_adapdata(&i2c->adap, i2c);
> > +
> > + ret = i2c_add_adapter(&i2c->adap);
> > + if (ret) {
> > + dev_err(&pdev->dev, "i2c add adapter failed = %d\n", ret);
> > + pci1xxxx_i2c_shutdown(i2c);
>
> Why do you call here pci1xxxx_i2c_shutdown() but not in previous error path?
pci1xxxx_i2c_shutdown API will reset the registers that are set as part of
pci1xxxx_i2c_init API. I will update this API and also include this API in
failure case of pci_alloc_irq_vectors as well as devm_request_irq
> > + goto err_free_region;
> > + }
> > +
> > + return 0;
> > +
> > +err_free_region:
> > + pci_free_irq_vectors(pdev);
> > + return ret;
> > +}
> > +
> > +static void pci1xxxx_i2c_remove_pci(struct pci_dev *pdev)
> > +{
> > + struct pci1xxxx_i2c *i2c = pci_get_drvdata(pdev);
>
> No need for pci_free_irq_vectors()?
>
I will add this API in pci1xxxx_i2c_remove_pci
> > +
> > + i2c_del_adapter(&i2c->adap);
> > + pci1xxxx_i2c_shutdown(i2c);
> > +}
> > +
Thank you,
Tharun Kumar P
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