Re: [PATCH v6 2/2] spi: loongson: add bus driver for the loongson spi controller

[zhuyinbo]

在 2023/4/2 下午7:44, Christophe JAILLET 写道:
> Le 01/04/2023 à 11:56, Yinbo Zhu a écrit :
> > This bus driver supports the Loongson spi hardware controller in the
> > Loongson platforms and supports to use DTS and PCI framework to
> > register spi device resources.
> >
> > Signed-off-by: Yinbo Zhu 
> > <zhuyinbo-cXZgJK919ebM1kAEIRd3EQ@xxxxxxxxxxxxxxxx>
> > ---
>
> [...]
>
> > +int loongson_spi_init_master(struct device *dev, struct resource *res)
> > +{
> > +    struct spi_master *master;
> > +    struct loongson_spi *spi;
> > +    struct clk *clk;
> > +    int ret;
> > +
> > +    master = spi_alloc_master(dev, sizeof(struct loongson_spi));
>
> devm_spi_alloc_master()?
> (to simplify code and be consistent with devm_ function below)
okay, I got it, I will use it.
> > +    if (master == NULL) {
> > +        dev_dbg(dev, "master allocation failed\n");
> > +        return -ENOMEM;
> > +    }
> > +
> > +    master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
> > +    master->setup = loongson_spi_setup;
> > +    master->prepare_message = loongson_spi_prepare_message;
> > +    master->transfer_one = loongson_spi_transfer_one;
> > +    master->unprepare_message = loongson_spi_unprepare_message;
> > +    master->set_cs = loongson_spi_set_cs;
> > +    master->num_chipselect = 4;
> > +    master->dev.of_node = of_node_get(dev->of_node);
> > +    dev_set_drvdata(dev, master);
> > +
> > +    spi = spi_master_get_devdata(master);
> > +
> > +    spi->master = master;
> > +
> > +    spi->base = devm_ioremap(dev, res->start, resource_size(res));
> > +    if (spi->base == NULL) {
> > +        dev_err(dev, "cannot map io\n");
> > +        ret = -ENXIO;
> > +        goto free_master;
> > +    }
> > +
> > +    clk = devm_clk_get(dev, NULL);
> > +    if (!IS_ERR(clk))
> > +        spi->clk_rate = clk_get_rate(clk);
> > +
> > +    loongson_spi_reginit(spi);
> > +
> > +    spi->mode = 0;
> > +    if (of_get_property(dev->of_node, "spi-nocs", NULL))
> > +        spi->mode |= SPI_NO_CS;
> > +
> > +    ret = spi_register_master(master);
> > +    if (ret < 0)
> > +        goto free_master;
> > +
> > +    return ret;
> > +
> > +free_master:
> > +    kfree(master);
> > +    spi_master_put(master);
> > +
> > +    return ret;
> > +}
> > +EXPORT_SYMBOL_GPL(loongson_spi_init_master);
>
> [...]
>
> > diff --git a/drivers/spi/spi-loongson-pci.c 
> > b/drivers/spi/spi-loongson-pci.c
> > new file mode 100644
> > index 000000000000..b811de769ecb
> > --- /dev/null
> > +++ b/drivers/spi/spi-loongson-pci.c
> > @@ -0,0 +1,89 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +// PCI interface driver for Loongson SPI Support
> > +// Copyright (C) 2023 Loongson Technology Corporation Limited
> > +
> > +#include <linux/pci.h>
> > +
> > +#include "spi-loongson.h"
> > +
> > +static int loongson_spi_pci_register(struct pci_dev *pdev,
> > +            const struct pci_device_id *ent)
> > +{
> > +    int ret;
> > +    unsigned char v8;
> > +    struct resource res[2];
> > +    struct device *dev = &pdev->dev;
> > +
> > +    ret = pci_enable_device(pdev);
> > +    if (ret < 0) {
> > +        dev_err(dev, "cannot enable pci device\n");
> > +        goto err_out;
> > +    }
> > +
> > +    ret = pci_request_region(pdev, 0, "loongson-spi io");
> > +    if (ret < 0) {
> > +        dev_err(dev, "cannot request region 0.\n");
> > +        goto err_out;
> > +    }
> > +
> > +    res[0].start = pci_resource_start(pdev, 0);
> > +    res[0].end = pci_resource_end(pdev, 0);
> > +    ret = pci_read_config_byte(pdev, PCI_INTERRUPT_LINE, &v8);
> > +
> > +    if (ret == PCIBIOS_SUCCESSFUL) {
> > +        res[1].start = v8;
> > +        res[1].end = v8;
> > +    }
> > +
> > +    ret = loongson_spi_init_master(dev, res);
> > +    if (ret)
> > +        dev_err(dev, "failed to initialize master\n");
> > +
> > +err_out:
> > +    return ret;
> > +}
> > +
> > +static void loongson_spi_pci_unregister(struct pci_dev *pdev)
> > +{
> > +    pci_release_region(pdev, 0);
>
> pci_disable_device()?
okay, I will add pci_disable_device() here.

Thanks.
> > +}
>
> CJ