From a532955fcee3d37eb4332cea2b868f74ace0bc72 Mon Sep 17 00:00:00 2001 From: Yinbo Zhu Date: Fri, 17 Mar 2023 16:29:50 +0800 Subject: [PATCH] spi: loongson: add bus driver for the loongson spi controller 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 --- MAINTAINERS | 1 + drivers/spi/Kconfig | 10 + drivers/spi/Makefile | 1 + drivers/spi/spi-loongson.c | 459 +++++++++++++++++++++++++++++++++++++ 4 files changed, 471 insertions(+) create mode 100644 drivers/spi/spi-loongson.c diff --git a/MAINTAINERS b/MAINTAINERS index debaa4c8636620..6780b1daba4938 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -12128,6 +12128,7 @@ M: Yinbo Zhu L: linux-spi@vger.kernel.org S: Maintained F: Documentation/devicetree/bindings/spi/loongson,ls-spi.yaml +F: drivers/spi/spi-loongson.c LSILOGIC MPT FUSION DRIVERS (FC/SAS/SPI) M: Sathya Prakash diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index cbf60b6a931c13..fce551d2ad10e7 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -509,6 +509,16 @@ config SPI_LM70_LLP which interfaces to an LM70 temperature sensor using a parallel port. +config SPI_LOONGSON + tristate "Loongson SPI Controller Support" + 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 and 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_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 d87cf75bee6a45..cab3ff6d18142e 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -70,6 +70,7 @@ 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-$(CONFIG_SPI_LOONGSON) += spi-loongson.o obj-$(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.c b/drivers/spi/spi-loongson.c new file mode 100644 index 00000000000000..2f4d0ca22a6300 --- /dev/null +++ b/drivers/spi/spi-loongson.c @@ -0,0 +1,459 @@ +// SPDX-License-Identifier: GPL-2.0+ +// Loongson SPI Support +// Copyright (C) 2023 Loongson Technology Corporation Limited + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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 { + spinlock_t lock; + 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; +}; + +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(loongson_spi->clk_rate, hz); + if (div < 2) + div = 2; + if (div > 4096) + div = 4096; + + bit = fls(div) - 1; + if ((1<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; + + spin_lock(&loongson_spi->lock); + loongson_spi_update_state(loongson_spi, spi, NULL); + loongson_spi_set_cs(spi, 1); + spin_unlock(&loongson_spi->lock); + + 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); +} + +static 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)); + 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; + + spin_lock_init(&spi->lock); + + ret = spi_register_master(master); + if (ret < 0) + goto free_master; + + return ret; + +free_master: + kfree(master); + spi_master_put(master); + + return ret; +} + +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 int __maybe_unused loongson_spi_suspend(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->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); + + return 0; +} + +static const struct dev_pm_ops loongson_spi_dev_pm_ops = { + .suspend = loongson_spi_suspend, + .resume = loongson_spi_resume, +}; + +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_driver = { + .probe = loongson_spi_platform_probe, + .driver = { + .name = "loongson-spi", + .owner = THIS_MODULE, + .bus = &platform_bus_type, + .pm = &loongson_spi_dev_pm_ops, + .of_match_table = loongson_spi_id_table, + }, +}; + +#ifdef CONFIG_PCI +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); +} + +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, +}; +#endif + +static int __init loongson_spi_init(void) +{ + int ret; + + ret = platform_driver_register(&loongson_spi_driver); + if (ret) + return ret; +#ifdef CONFIG_PCI + ret = pci_register_driver(&loongson_spi_pci_driver); + if (ret) { + platform_driver_unregister(&loongson_spi_driver); + return ret; + } +#endif + return 0; +} + +static void __exit loongson_spi_exit(void) +{ + platform_driver_unregister(&loongson_spi_driver); +#ifdef CONFIG_PCI + pci_unregister_driver(&loongson_spi_pci_driver); +#endif +} + +module_init(loongson_spi_init); +module_exit(loongson_spi_exit); + +MODULE_DESCRIPTION("Loongson spi driver"); +MODULE_LICENSE("GPL");