[PATCH v9 2/2] spi: loongson: add bus driver for the loongson spi controller

Yinbo Zhu
2023-04-26T07:15:24Z

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@loongson.cn>
---
MAINTAINERS | 4 +
drivers/spi/Kconfig | 31 ++++
drivers/spi/Makefile | 3 +
drivers/spi/spi-loongson-core.c | 296 ++++++++++++++++++++++++++++++++
drivers/spi/spi-loongson-pci.c | 72 ++++++++
drivers/spi/spi-loongson-plat.c | 47 +++++
drivers/spi/spi-loongson.h | 41 +++++
7 files changed, 494 insertions(+)
create mode 100644 drivers/spi/spi-loongson-core.c
create mode 100644 drivers/spi/spi-loongson-pci.c
create mode 100644 drivers/spi/spi-loongson-plat.c
create mode 100644 drivers/spi/spi-loongson.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 0dcf4cfbe178..4a629b9b5a4e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12162,6 +12162,10 @@ M: Yinbo Zhu <zhuyinbo@loongson.cn>
L: linux-spi@vger.kernel.org
S: Maintained
F: Documentation/devicetree/bindings/spi/loongson,ls2k-spi.yaml
+F: drivers/spi/spi-loongson-core.c
+F: drivers/spi/spi-loongson-pci.c
+F: drivers/spi/spi-loongson-plat.c
+F: drivers/spi/spi-loongson.h

LSILOGIC MPT FUSION DRIVERS (FC/SAS/SPI)
M: Sathya Prakash <sathya.prakash@broadcom.com>
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index cbf60b6a931c..87f87ee35d27 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -509,6 +509,37 @@ config SPI_LM70_LLP
which interfaces to an LM70 temperature sensor using
a parallel port.

+config SPI_LOONGSON_CORE
+ tristate "Loongson SPI Controller Core Driver Support"
+ depends on LOONGARCH || COMPILE_TEST
+ help
+ This core driver supports the Loongson spi hardware controller in
+ the Loongson platforms.
+ Say Y or M here if you want to use the SPI controller on
+ Loongson platform.
+
+config SPI_LOONGSON_PCI
+ tristate "Loongson SPI Controller PCI Driver Support"
+ select SPI_LOONGSON_CORE
+ depends on PCI && (LOONGARCH || COMPILE_TEST)
+ help
+ This bus driver supports the Loongson spi hardware controller in
+ the Loongson platforms and supports to use PCI framework to
+ register spi device resources.
+ Say Y or M here if you want to use the SPI controller on
+ Loongson platform.
+
+config SPI_LOONGSON_PLATFORM
+ tristate "Loongson SPI Controller Platform Driver Support"
+ select SPI_LOONGSON_CORE
+ depends on OF && (LOONGARCH || COMPILE_TEST)
+ help
+ This bus driver supports the Loongson spi hardware controller in
+ the Loongson platforms and supports to use DTS framework to
+ register spi device resources.
+ Say Y or M here if you want to use the SPI controller on
+ Loongson platform.
+
config SPI_LP8841_RTC
tristate "ICP DAS LP-8841 SPI Controller for RTC"
depends on MACH_PXA27X_DT || COMPILE_TEST
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index d87cf75bee6a..a4931aa64476 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -70,6 +70,9 @@ obj-$(CONFIG_SPI_INTEL_PLATFORM) += spi-intel-platform.o
obj-$(CONFIG_SPI_LANTIQ_SSC) += spi-lantiq-ssc.o
obj-$(CONFIG_SPI_JCORE) += spi-jcore.o
obj-$(CONFIG_SPI_LM70_LLP) += spi-lm70llp.o
+obj-$(CONFIG_SPI_LOONGSON_CORE) += spi-loongson-core.o
+obj-$(CONFIG_SPI_LOONGSON_PCI) += spi-loongson-pci.o
+obj-$(CONFIG_SPI_LOONGSON_PLATFORM) += spi-loongson-plat.o
obj-$(CONFIG_SPI_LP8841_RTC) += spi-lp8841-rtc.o
obj-$(CONFIG_SPI_MESON_SPICC) += spi-meson-spicc.o
obj-$(CONFIG_SPI_MESON_SPIFC) += spi-meson-spifc.o
diff --git a/drivers/spi/spi-loongson-core.c b/drivers/spi/spi-loongson-core.c
new file mode 100644
index 000000000000..4c0b5c5fcab4
--- /dev/null
+++ b/drivers/spi/spi-loongson-core.c
@@ -0,0 +1,296 @@
+// SPDX-License-Identifier: GPL-2.0+
+// Loongson SPI Support
+// Copyright (C) 2023 Loongson Technology Corporation Limited
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/spi/spi.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+
+#include "spi-loongson.h"
+
+static inline void loongson_spi_write_reg(struct loongson_spi *spi, unsigned char reg,
+ unsigned char data)
+{
+ writeb(data, spi->base + reg);
+}
+
+static inline char loongson_spi_read_reg(struct loongson_spi *spi, unsigned char reg)
+{
+ return readb(spi->base + reg);
+}
+
+static void loongson_spi_set_cs(struct spi_device *spi, bool val)
+{
+ int cs;
+ struct loongson_spi *loongson_spi = spi_master_get_devdata(spi->master);
+
+ if (loongson_spi->mode & SPI_NO_CS)
+ loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_SFCS_REG, 0);
+ else {
+ cs = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_SFCS_REG)
+ & ~(0x11 << spi->chip_select);
+ loongson_spi_write_reg(loongson_spi,
+ LOONGSON_SPI_SFCS_REG,
+ (val ? (0x11 << spi->chip_select) :
+ (0x1 << spi->chip_select)) | cs);
+ }
+}
+
+static int loongson_spi_update_state(struct loongson_spi *loongson_spi,
+ struct spi_device *spi, struct spi_transfer *t)
+{
+ unsigned int hz;
+ unsigned int div, div_tmp;
+ unsigned int bit;
+ unsigned char val;
+ const char rdiv[12] = {0, 1, 4, 2, 3, 5, 6, 7, 8, 9, 10, 11};
+
+ if (t)
+ hz = t->speed_hz;
+
+ if ((hz && loongson_spi->hz != hz) ||
+ ((spi->mode ^ loongson_spi->mode) & (SPI_CPOL | SPI_CPHA))) {
+ div = DIV_ROUND_UP_ULL(loongson_spi->clk_rate, hz);
+ if (div < 2)
+ div = 2;
+ if (div > 4096)
+ div = 4096;
+
+ bit = fls(div) - 1;
+ if ((1<<bit) == div)
+ bit--;
+ div_tmp = rdiv[bit];
+ dev_dbg(&spi->dev, "clk_rate = %llu hz = %d div_tmp = %d bit = %d\n",
+ loongson_spi->clk_rate, hz, div_tmp, bit);
+
+ loongson_spi->hz = hz;
+ loongson_spi->spcr = div_tmp & 3;
+ loongson_spi->sper = (div_tmp >> 2) & 3;
+ val = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_SPCR_REG);
+ val &= ~0xc;
+ if (spi->mode & SPI_CPOL)
+ val |= 8;
+ if (spi->mode & SPI_CPHA)
+ val |= 4;
+
+ loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_SPCR_REG, (val & ~3) |
+ loongson_spi->spcr);
+ val = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_SPER_REG);
+ loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_SPER_REG, (val & ~3) |
+ loongson_spi->sper);
+ loongson_spi->mode &= SPI_NO_CS;
+ loongson_spi->mode |= spi->mode;
+ }
+
+ return 0;
+}
+
+static int loongson_spi_setup(struct spi_device *spi)
+{
+ struct loongson_spi *loongson_spi;
+
+ loongson_spi = spi_master_get_devdata(spi->master);
+ if (spi->bits_per_word % 8)
+ return -EINVAL;
+
+ if (spi->chip_select >= spi->master->num_chipselect)
+ return -EINVAL;
+
+ loongson_spi->hz = 0;
+ loongson_spi->mode &= SPI_NO_CS;
+ loongson_spi_set_cs(spi, 1);
+
+ return 0;
+}
+
+static int loongson_spi_write_read_8bit(struct spi_device *spi, const u8 **tx_buf,
+ u8 **rx_buf, unsigned int num)
+{
+ struct loongson_spi *loongson_spi = spi_master_get_devdata(spi->master);
+ unsigned long timeout = jiffies + SPI_COMPLETION_TIMEOUT;
+
+ if (tx_buf && *tx_buf) {
+ loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_FIFO_REG, *((*tx_buf)++));
+ while ((loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_SPSR_REG) & 0x1) == 1 &&
+ time_after(timeout, jiffies))
+ cpu_relax();
+ } else {
+ loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_FIFO_REG, 0);
+ while ((loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_SPSR_REG) & 0x1) == 1 &&
+ time_after(timeout, jiffies))
+ cpu_relax();
+ }
+
+ if (rx_buf && *rx_buf)
+ *(*rx_buf)++ = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_FIFO_REG);
+ else
+ loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_FIFO_REG);
+
+ return 0;
+}
+
+static unsigned int loongson_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)
+{
+ unsigned int count;
+ const u8 *tx = xfer->tx_buf;
+ u8 *rx = xfer->rx_buf;
+
+ count = xfer->len;
+
+ do {
+ if (loongson_spi_write_read_8bit(spi, &tx, &rx, count) < 0)
+ goto out;
+ count--;
+ } while (count);
+
+out:
+ return xfer->len - count;
+}
+
+static int loongson_spi_prepare_message(struct spi_controller *ctlr, struct spi_message *m)
+{
+ struct loongson_spi *loongson_spi = spi_controller_get_devdata(ctlr);
+
+ loongson_spi->para = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_PARA_REG);
+ loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_PARA_REG, loongson_spi->para & ~1);
+
+ return 0;
+}
+
+static int loongson_spi_transfer_one(struct spi_controller *ctrl, struct spi_device *spi,
+ struct spi_transfer *xfer)
+{
+ struct loongson_spi *loongson_spi = spi_master_get_devdata(spi->master);
+
+ loongson_spi_update_state(loongson_spi, spi, xfer);
+ if (xfer->len)
+ xfer->len = loongson_spi_write_read(spi, xfer);
+
+ return 0;
+}
+
+static int loongson_spi_unprepare_message(struct spi_controller *ctrl, struct spi_message *m)
+{
+ struct loongson_spi *loongson_spi = spi_controller_get_devdata(ctrl);
+
+ loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_PARA_REG, loongson_spi->para);
+
+ return 0;
+}
+
+static void loongson_spi_reginit(struct loongson_spi *loongson_spi_dev)
+{
+ unsigned char val;
+
+ val = loongson_spi_read_reg(loongson_spi_dev, LOONGSON_SPI_SPCR_REG);
+ val &= ~LOONGSON_SPI_SPCR_SPE;
+ loongson_spi_write_reg(loongson_spi_dev, LOONGSON_SPI_SPCR_REG, val);
+
+ loongson_spi_write_reg(loongson_spi_dev, LOONGSON_SPI_SPSR_REG,
+ (LOONGSON_SPI_SPSR_SPIF | LOONGSON_SPI_SPSR_WCOL));
+
+ val = loongson_spi_read_reg(loongson_spi_dev, LOONGSON_SPI_SPCR_REG);
+ val |= LOONGSON_SPI_SPCR_SPE;
+ loongson_spi_write_reg(loongson_spi_dev, LOONGSON_SPI_SPCR_REG, val);
+}
+
+int loongson_spi_init_master(struct device *dev, struct resource *res)
+{
+ struct spi_master *master;
+ struct loongson_spi *spi;
+ struct clk *clk;
+
+ master = devm_spi_alloc_master(dev, sizeof(struct loongson_spi));
+ if (master == NULL) {
+ dev_info(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");
+ return -ENXIO;
+ }
+
+ 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;
+
+ return devm_spi_register_master(dev, master);
+}
+EXPORT_SYMBOL_GPL(loongson_spi_init_master);
+
+static int __maybe_unused loongson_spi_suspend(struct device *dev)
+{
+ struct loongson_spi *loongson_spi;
+ struct spi_master *master;
+
+ master = dev_get_drvdata(dev);
+ spi_master_suspend(master);
+
+ loongson_spi = spi_master_get_devdata(master);
+
+ loongson_spi->spcr = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_SPCR_REG);
+ loongson_spi->sper = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_SPER_REG);
+ loongson_spi->spsr = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_SPSR_REG);
+ loongson_spi->para = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_PARA_REG);
+ loongson_spi->sfcs = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_SFCS_REG);
+ loongson_spi->timi = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_TIMI_REG);
+
+ return 0;
+}
+
+static int __maybe_unused loongson_spi_resume(struct device *dev)
+{
+ struct loongson_spi *loongson_spi;
+ struct spi_master *master;
+
+ master = dev_get_drvdata(dev);
+ loongson_spi = spi_master_get_devdata(master);
+
+ loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_SPCR_REG, loongson_spi->spcr);
+ loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_SPER_REG, loongson_spi->sper);
+ loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_SPSR_REG, loongson_spi->spsr);
+ loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_PARA_REG, loongson_spi->para);
+ loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_SFCS_REG, loongson_spi->sfcs);
+ loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_TIMI_REG, loongson_spi->timi);
+
+ spi_master_resume(master);
+
+ return 0;
+}
+
+const struct dev_pm_ops loongson_spi_dev_pm_ops = {
+ .suspend = loongson_spi_suspend,
+ .resume = loongson_spi_resume,
+};
+EXPORT_SYMBOL_GPL(loongson_spi_dev_pm_ops);
+
+MODULE_DESCRIPTION("Loongson spi core driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/spi/spi-loongson-pci.c b/drivers/spi/spi-loongson-pci.c
new file mode 100644
index 000000000000..f8aaad6577bd
--- /dev/null
+++ b/drivers/spi/spi-loongson-pci.c
@@ -0,0 +1,72 @@
+// 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(pdev);
+}
+
+static struct pci_device_id loongson_spi_devices[] = {
+ {PCI_DEVICE(0x14, 0x7a0b)},
+ {PCI_DEVICE(0x14, 0x7a1b)},
+ {0, 0, 0, 0, 0, 0, 0}
+};
+MODULE_DEVICE_TABLE(pci, loongson_spi_devices);
+
+static struct pci_driver loongson_spi_pci_driver = {
+ .name = "loongson-spi-pci",
+ .id_table = loongson_spi_devices,
+ .probe = loongson_spi_pci_register,
+ .remove = loongson_spi_pci_unregister,
+ .driver = {
+ .bus = &pci_bus_type,
+ .pm = &loongson_spi_dev_pm_ops,
+ },
+};
+module_pci_driver(loongson_spi_pci_driver);
+
+MODULE_DESCRIPTION("Loongson spi pci driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/spi/spi-loongson-plat.c b/drivers/spi/spi-loongson-plat.c
new file mode 100644
index 000000000000..acf0fa38ce4b
--- /dev/null
+++ b/drivers/spi/spi-loongson-plat.c
@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: GPL-2.0+
+// Platform driver for Loongson SPI Support
+// Copyright (C) 2023 Loongson Technology Corporation Limited
+
+#include <linux/platform_device.h>
+#include <linux/of.h>
+
+#include "spi-loongson.h"
+
+static int loongson_spi_platform_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct resource *res;
+ int ret;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (res == NULL) {
+ dev_err(dev, "cannot get io resource memory\n");
+ return -ENOENT;
+ }
+
+ ret = loongson_spi_init_master(dev, res);
+ if (ret)
+ dev_err(dev, "failed to initialize master\n");
+
+ return ret;
+}
+
+static const struct of_device_id loongson_spi_id_table[] = {
+ { .compatible = "loongson,ls2k-spi", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, loongson_spi_id_table);
+
+static struct platform_driver loongson_spi_plat_driver = {
+ .probe = loongson_spi_platform_probe,
+ .driver = {
+ .name = "loongson-spi",
+ .bus = &platform_bus_type,
+ .pm = &loongson_spi_dev_pm_ops,
+ .of_match_table = loongson_spi_id_table,
+ },
+};
+module_platform_driver(loongson_spi_plat_driver);
+
+MODULE_DESCRIPTION("Loongson spi platform driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/spi/spi-loongson.h b/drivers/spi/spi-loongson.h
new file mode 100644
index 000000000000..44818340188d
--- /dev/null
+++ b/drivers/spi/spi-loongson.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/* Header File for Loongson SPI Driver. */
+/* Copyright (C) 2023 Loongson Technology Corporation Limited */
+
+#ifndef __LINUX_SPI_LOONGSON_H
+#define __LINUX_SPI_LOONGSON_H
+
+#define LOONGSON_SPI_SPCR_REG 0x00
+#define LOONGSON_SPI_SPSR_REG 0x01
+#define LOONGSON_SPI_FIFO_REG 0x02
+#define LOONGSON_SPI_SPER_REG 0x03
+#define LOONGSON_SPI_PARA_REG 0x04
+#define LOONGSON_SPI_SFCS_REG 0x05
+#define LOONGSON_SPI_TIMI_REG 0x06
+
+/* Bits definition for Loongson SPI register */
+#define LOONGSON_SPI_PARA_MEM_EN BIT(0)
+#define LOONGSON_SPI_SPSR_SPIF BIT(7)
+#define LOONGSON_SPI_SPSR_WCOL BIT(6)
+#define LOONGSON_SPI_SPCR_SPE BIT(6)
+
+#define SPI_COMPLETION_TIMEOUT msecs_to_jiffies(2000)
+
+struct loongson_spi {
+ struct spi_master *master;
+ void __iomem *base;
+ int cs_active;
+ unsigned int hz;
+ unsigned char spcr;
+ unsigned char sper;
+ unsigned char spsr;
+ unsigned char para;
+ unsigned char sfcs;
+ unsigned char timi;
+ unsigned int mode;
+ u64 clk_rate;
+};
+
+extern int loongson_spi_init_master(struct device *dev, struct resource *res);
+extern const struct dev_pm_ops loongson_spi_dev_pm_ops;
+#endif /* __LINUX_SPI_LOONGSON_H */
--
2.20.1