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SubjectRe: [PATCH v1 1/5] spi: spi-gxp: Add support for HPE GXP SoCs
From
Hi,

a few nitpicks below, should there be a v2.

Le 20/07/2022 à 22:11, nick.hawkins-ZPxbGqLxI0U@public.gmane.org a écrit :
> From: Nick Hawkins <nick.hawkins-ZPxbGqLxI0U@public.gmane.org>
>
> The GXP supports 3 separate SPI interfaces to accommodate the system
> flash, core flash, and other functions. The SPI engine supports variable
> clock frequency, selectable 3-byte or 4-byte addressing and a
> configurable x1, x2, and x4 command/address/data modes. The memory
> buffer for reading and writing ranges between 256 bytes and 8KB. This
> driver supports access to the core flash and bios part.
>
> Signed-off-by: Nick Hawkins <nick.hawkins-ZPxbGqLxI0U@public.gmane.org>
> ---
> drivers/spi/Kconfig | 7 +
> drivers/spi/Makefile | 1 +
> drivers/spi/spi-gxp.c | 355 ++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 363 insertions(+)
> create mode 100644 drivers/spi/spi-gxp.c
>

[...]

> diff --git a/drivers/spi/spi-gxp.c b/drivers/spi/spi-gxp.c
> new file mode 100644
> index 000000000000..85e800718d8a
> --- /dev/null
> +++ b/drivers/spi/spi-gxp.c
> @@ -0,0 +1,355 @@
> +// SPDX-License-Identifier: GPL-2.0=or-later
> +/* Copyright (C) 2022 Hewlett-Packard Development Company, L.P. */
> +
> +#include <linux/iopoll.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/spi/spi.h>
> +#include <linux/spi/spi.h>

Same include twice.

> +#include <linux/spi/spi-mem.h>
> +

[...]

> +static int gxp_spi_read_reg(struct gxp_spi_chip *chip, const struct spi_mem_op *op)
> +{
> + int ret = 0;

Useless initialization.

> + struct gxp_spi *spifi = chip->spifi;
> + void __iomem *reg_base = spifi->reg_base;
> + u32 value;
> + int cs;
> +
> + cs = chip->cs;

Could be set in the initialization, as for the 2 other variables.
(if it makes sense)

> +
> + value = readl(reg_base + OFFSET_SPIMCFG);
> + value &= ~(1 << 24);
> + value |= (cs << 24);
> + value &= ~(0x07 << 16);
> + value &= ~(0x1f << 19);
> + writel(value, reg_base + OFFSET_SPIMCFG);
> +
> + writel(0, reg_base + OFFSET_SPIADDR);
> +
> + writeb(op->cmd.opcode, reg_base + OFFSET_SPICMD);
> +
> + writew(op->data.nbytes, reg_base + OFFSET_SPIDCNT);
> +
> + value = readb(reg_base + OFFSET_SPIMCTRL);
> + value &= ~SPIMCTRL_DIR;
> + value |= SPIMCTRL_START;
> +
> + writeb(value, reg_base + OFFSET_SPIMCTRL);
> +
> + ret = readb_poll_timeout(reg_base + OFFSET_SPIMCTRL, value,
> + !(value & SPIMCTRL_BUSY),
> + GXP_SPI_SLEEP_TIME, GXP_SPI_TIMEOUT);
> + if (ret) {
> + dev_warn(spifi->dev, "read reg busy time out\n");
> + return ret;
> + }
> +
> + memcpy_fromio(op->data.buf.in, spifi->dat_base, op->data.nbytes);
> + return ret;
> +}
> +
> +static int gxp_spi_write_reg(struct gxp_spi_chip *chip, const struct spi_mem_op *op)
> +{
> + int ret = 0;

Useless initialization.

> + struct gxp_spi *spifi = chip->spifi;
> + void __iomem *reg_base = spifi->reg_base;
> + u32 value;
> + int cs;
> +
> + cs = chip->cs;

Could be set in the initialization, as for the 2 other variables.
(if it makes sense)

> +
> + value = readl(reg_base + OFFSET_SPIMCFG);
> + value &= ~(1 << 24);
> + value |= (cs << 24);
> + value &= ~(0x07 << 16);
> + value &= ~(0x1f << 19);
> + writel(value, reg_base + OFFSET_SPIMCFG);
> +
> + writel(0, reg_base + OFFSET_SPIADDR);
> +
> + writeb(op->cmd.opcode, reg_base + OFFSET_SPICMD);
> +
> + memcpy_toio(spifi->dat_base, op->data.buf.in, op->data.nbytes);
> +
> + writew(op->data.nbytes, reg_base + OFFSET_SPIDCNT);
> +
> + value = readb(reg_base + OFFSET_SPIMCTRL);
> + value |= SPIMCTRL_DIR;
> + value |= SPIMCTRL_START;
> +
> + writeb(value, reg_base + OFFSET_SPIMCTRL);
> +
> + ret = readb_poll_timeout(reg_base + OFFSET_SPIMCTRL, value,
> + !(value & SPIMCTRL_BUSY),
> + GXP_SPI_SLEEP_TIME, GXP_SPI_TIMEOUT);
> + if (ret)
> + dev_warn(spifi->dev, "write reg busy time out\n");
> +
> + return ret;
> +}
> +
> +static ssize_t gxp_spi_read(struct gxp_spi_chip *chip, const struct spi_mem_op *op)
> +{
> + int cs;
> + struct gxp_spi *spifi = chip->spifi;
> + u32 offset = op->addr.val;
> +
> + cs = chip->cs;

Could be set in the initialization, as for the 2 other variables.
(if it makes sense)

> +
> + if (cs == 0)
> + offset += 0x4000000;
> +
> + memcpy_fromio(op->data.buf.in, spifi->dir_base + offset, op->data.nbytes);
> +
> + return 0;
> +}
> +
> +static ssize_t gxp_spi_write(struct gxp_spi_chip *chip, const struct spi_mem_op *op)
> +{
> + struct gxp_spi *spifi = chip->spifi;
> + void __iomem *reg_base = spifi->reg_base;
> + u32 write_len;
> + u32 value;
> + int cs;
> + int ret = 0;

Useless initialization.

> +
> + cs = chip->cs;

Could be set in the initialization, as for the 2 other variables.
(if it makes sense)

> +
> + write_len = op->data.nbytes;
> + if (write_len > SPILDAT_LEN)
> + write_len = SPILDAT_LEN;
> +
> + value = readl(reg_base + OFFSET_SPIMCFG);
> + value &= ~(1 << 24);
> + value |= (cs << 24);
> + value &= ~(0x07 << 16);
> + value |= (op->addr.nbytes << 16);
> + value &= ~(0x1f << 19);
> + writel(value, reg_base + OFFSET_SPIMCFG);
> +
> + writel(op->addr.val, reg_base + OFFSET_SPIADDR);
> +
> + writeb(op->cmd.opcode, reg_base + OFFSET_SPICMD);
> +
> + writew(write_len, reg_base + OFFSET_SPIDCNT);
> +
> + memcpy_toio(spifi->dat_base, op->data.buf.in, write_len);
> +
> + value = readb(reg_base + OFFSET_SPIMCTRL);
> + value |= SPIMCTRL_DIR;
> + value |= SPIMCTRL_START;
> +
> + writeb(value, reg_base + OFFSET_SPIMCTRL);
> +
> + ret = readb_poll_timeout(reg_base + OFFSET_SPIMCTRL, value,
> + !(value & SPIMCTRL_BUSY),
> + GXP_SPI_SLEEP_TIME, GXP_SPI_TIMEOUT);
> + if (ret) {
> + dev_warn(spifi->dev, "write busy time out\n");
> + return ret;
> + }
> +
> + return write_len;
> +}
> +
> +static int do_gxp_exec_mem_op(struct spi_mem *mem, const struct spi_mem_op *op)
> +{
> + struct gxp_spi *spifi = spi_controller_get_devdata(mem->spi->master);
> + struct gxp_spi_chip *chip = &spifi->chips[mem->spi->chip_select];

Useless empty line.

> +
> + int ret = 0;

Useless initialization. (But I'm not sure the compiler is smart enough
to see it)

> +
> + if (op->data.dir == SPI_MEM_DATA_IN) {
> + if (!op->addr.nbytes)
> + ret = gxp_spi_read_reg(chip, op);
> + else
> + ret = gxp_spi_read(chip, op);
> + } else {
> + if (!op->addr.nbytes)
> + ret = gxp_spi_write_reg(chip, op);
> + else
> + ret = gxp_spi_write(chip, op);
> + }
> +
> + return ret;
> +}

[...]

> +static int gxp_spifi_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + const struct gxp_spi_data *data;
> + struct spi_controller *ctlr;
> + struct gxp_spi *spifi;
> + struct resource *res;
> + int ret;
> +
> + data = of_device_get_match_data(&pdev->dev);
> + if (!data) {
> + dev_err(&pdev->dev, "of_dev_get_match_data failed\n");
> + return -ENOMEM;
> + }
> +
> + ctlr = devm_spi_alloc_master(dev, sizeof(*spifi));
> + if (!ctlr) {
> + dev_err(&pdev->dev, "spi_alloc_master failed\n");
> + return -ENOMEM;
> + }
> +
> + spifi = spi_controller_get_devdata(ctlr);
> + if (!spifi) {
> + dev_err(&pdev->dev, "spi_controller_get_data failed\n");
> + return -ENOMEM;
> + }
> +
> + platform_set_drvdata(pdev, spifi);
> + spifi->data = data;
> + spifi->dev = dev;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + spifi->reg_base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(spifi->reg_base))
> + return PTR_ERR(spifi->reg_base);
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> + spifi->dat_base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(spifi->dat_base))
> + return PTR_ERR(spifi->dat_base);
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
> + spifi->dir_base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(spifi->dir_base))
> + return PTR_ERR(spifi->dir_base);
> +
> + ctlr->mode_bits = data->mode_bits;
> + ctlr->bus_num = pdev->id;
> + ctlr->mem_ops = &gxp_spi_mem_ops;
> + ctlr->setup = gxp_spi_setup;
> + ctlr->num_chipselect = data->max_cs;
> + ctlr->dev.of_node = dev->of_node;
> +
> + ret = devm_spi_register_controller(dev, ctlr);
> + if (ret) {
> + dev_err(&pdev->dev, "spi_register_controller failed\n");
> + return ret;

Could be return dev_err_probe(), but it is mostly a matter of taste, I
guess.

CJ

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