Re: [PATCH v1 1/5] spi: spi-gxp: Add support for HPE GXP SoCs
From: Christophe JAILLET
Date: Thu Jul 21 2022 - 12:04:58 EST
Hi,
a few nitpicks below, should there be a v2.
Le 20/07/2022 à 22:11, nick.hawkins-ZPxbGqLxI0U@xxxxxxxxxxxxxxxx a écrit :
From: Nick Hawkins <nick.hawkins-ZPxbGqLxI0U@xxxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxxx>
---
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