[PATCH v4 1/5] spi: spi-gxp: Add support for HPE GXP SoCs

nick.hawkins
2022-07-25T20:15:02Z

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@hpe.com>

---
v4:
*No change
v3:
*No change
v2:
*Removed repeated include file
*Removed unnecessary initialization of ret variable
*Removed conditional variable checks where failure is impossible
*Removed unecessary variable cs and instead used in the initialization
*Removed blank gxp_spifi_remove function
*Fixed error messages so they are not repetitive
---
drivers/spi/Kconfig | 7 +
drivers/spi/Makefile | 1 +
drivers/spi/spi-gxp.c | 325 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 333 insertions(+)
create mode 100644 drivers/spi/spi-gxp.c

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 3b1044ebc400..543e4a5b5ffa 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -371,6 +371,13 @@ config SPI_FSL_QUADSPI
This controller does not support generic SPI messages. It only
supports the high-level SPI memory interface.

+config SPI_GXP
+ tristate "GXP SPI driver"
+ depends on ARCH_HPE || COMPILE_TEST
+ help
+ This enables support for the driver for GXP bus attached SPI
+ controllers.
+
config SPI_HISI_KUNPENG
tristate "HiSilicon SPI Controller for Kunpeng SoCs"
depends on (ARM64 && ACPI) || COMPILE_TEST
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 0f44eb6083a5..ca5f204017ee 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -57,6 +57,7 @@ obj-$(CONFIG_SPI_FSL_LPSPI) += spi-fsl-lpspi.o
obj-$(CONFIG_SPI_FSL_QUADSPI) += spi-fsl-qspi.o
obj-$(CONFIG_SPI_FSL_SPI) += spi-fsl-spi.o
obj-$(CONFIG_SPI_GPIO) += spi-gpio.o
+obj-$(CONFIG_SPI_GXP) += spi-gxp.o
obj-$(CONFIG_SPI_HISI_KUNPENG) += spi-hisi-kunpeng.o
obj-$(CONFIG_SPI_HISI_SFC_V3XX) += spi-hisi-sfc-v3xx.o
obj-$(CONFIG_SPI_IMG_SPFI) += spi-img-spfi.o
diff --git a/drivers/spi/spi-gxp.c b/drivers/spi/spi-gxp.c
new file mode 100644
index 000000000000..9ea355f7d64f
--- /dev/null
+++ b/drivers/spi/spi-gxp.c
@@ -0,0 +1,325 @@
+// 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-mem.h>
+
+#define GXP_SPI0_MAX_CHIPSELECT 2
+#define GXP_SPI_SLEEP_TIME 1
+#define GXP_SPI_TIMEOUT (130 * 1000000 / GXP_SPI_SLEEP_TIME)
+
+#define MANUAL_MODE 0
+#define DIRECT_MODE 1
+#define SPILDAT_LEN 256
+
+#define OFFSET_SPIMCFG 0x0
+#define OFFSET_SPIMCTRL 0x4
+#define OFFSET_SPICMD 0x5
+#define OFFSET_SPIDCNT 0x6
+#define OFFSET_SPIADDR 0x8
+#define OFFSET_SPIINTSTS 0xc
+
+#define SPIMCTRL_START 0x01
+#define SPIMCTRL_BUSY 0x02
+#define SPIMCTRL_DIR 0x08
+
+struct gxp_spi;
+
+struct gxp_spi_chip {
+ struct gxp_spi *spifi;
+ u32 cs;
+};
+
+struct gxp_spi_data {
+ u32 max_cs;
+ u32 mode_bits;
+};
+
+struct gxp_spi {
+ const struct gxp_spi_data *data;
+ void __iomem *reg_base;
+ void __iomem *dat_base;
+ void __iomem *dir_base;
+ struct device *dev;
+ struct gxp_spi_chip chips[GXP_SPI0_MAX_CHIPSELECT];
+};
+
+static void gxp_spi_set_mode(struct gxp_spi *spifi, int mode)
+{
+ u8 value;
+ void __iomem *reg_base = spifi->reg_base;
+
+ value = readb(reg_base + OFFSET_SPIMCTRL);
+
+ if (mode == MANUAL_MODE) {
+ writeb(0x55, reg_base + OFFSET_SPICMD);
+ writeb(0xaa, reg_base + OFFSET_SPICMD);
+ value &= ~0x30;
+ } else {
+ value |= 0x30;
+ }
+ writeb(value, reg_base + OFFSET_SPIMCTRL);
+}
+
+static int gxp_spi_read_reg(struct gxp_spi_chip *chip, const struct spi_mem_op *op)
+{
+ int ret;
+ struct gxp_spi *spifi = chip->spifi;
+ void __iomem *reg_base = spifi->reg_base;
+ u32 value;
+
+ value = readl(reg_base + OFFSET_SPIMCFG);
+ value &= ~(1 << 24);
+ value |= (chip->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;
+ struct gxp_spi *spifi = chip->spifi;
+ void __iomem *reg_base = spifi->reg_base;
+ u32 value;
+
+ value = readl(reg_base + OFFSET_SPIMCFG);
+ value &= ~(1 << 24);
+ value |= (chip->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)
+{
+ struct gxp_spi *spifi = chip->spifi;
+ u32 offset = op->addr.val;
+
+ if (chip->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 ret;
+
+ write_len = op->data.nbytes;
+ if (write_len > SPILDAT_LEN)
+ write_len = SPILDAT_LEN;
+
+ value = readl(reg_base + OFFSET_SPIMCFG);
+ value &= ~(1 << 24);
+ value |= (chip->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];
+ int ret;
+
+ 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_exec_mem_op(struct spi_mem *mem, const struct spi_mem_op *op)
+{
+ int ret;
+
+ ret = do_gxp_exec_mem_op(mem, op);
+ if (ret)
+ dev_err(&mem->spi->dev, "operation failed: %d", ret);
+
+ return ret;
+}
+
+static const struct spi_controller_mem_ops gxp_spi_mem_ops = {
+ .exec_op = gxp_exec_mem_op,
+};
+
+static int gxp_spi_setup(struct spi_device *spi)
+{
+ struct gxp_spi *spifi = spi_controller_get_devdata(spi->master);
+ unsigned int cs = spi->chip_select;
+ struct gxp_spi_chip *chip = &spifi->chips[cs];
+
+ chip->spifi = spifi;
+ chip->cs = cs;
+
+ gxp_spi_set_mode(spifi, MANUAL_MODE);
+
+ return 0;
+}
+
+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);
+
+ ctlr = devm_spi_alloc_master(dev, sizeof(*spifi));
+ if (!ctlr)
+ return -ENOMEM;
+
+ spifi = spi_controller_get_devdata(ctlr);
+
+ 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) {
+ return dev_err_probe(&pdev->dev, ret,
+ "failed to register spi controller\n");
+ }
+
+ return 0;
+}
+
+static const struct gxp_spi_data gxp_spifi_data = {
+ .max_cs = 2,
+ .mode_bits = 0,
+};
+
+static const struct of_device_id gxp_spifi_match[] = {
+ {.compatible = "hpe,gxp-spifi", .data = &gxp_spifi_data },
+ { /* null */ }
+};
+MODULE_DEVICE_TABLE(of, gxp_spifi_match);
+
+static struct platform_driver gxp_spifi_driver = {
+ .probe = gxp_spifi_probe,
+ .driver = {
+ .name = "gxp-spifi",
+ .of_match_table = gxp_spifi_match,
+ },
+};
+module_platform_driver(gxp_spifi_driver);
+
+MODULE_DESCRIPTION("HPE GXP SPI Flash Interface driver");
+MODULE_AUTHOR("Nick Hawkins <nick.hawkins@hpe.com>");
+MODULE_LICENSE("GPL");