Hi, Huacai On 12/28/2020 08:32 AM, Huacai Chen wrote:
Hi, Qing, On Sat, Dec 26, 2020 at 5:13 PM Qing Zhang <zhangqing@xxxxxxxxxxx> wrote:The SPI controller has the following characteristics: - Full-duplex synchronous serial data transmission - Support up to 4 variable length byte transmission - Main mode support - Mode failure generates an error flag and issues an interrupt request - Double buffer receiver - Serial clock with programmable polarity and phase - SPI can be controlled in wait mode - Support boot from SPI Use mtd_debug tool to earse/write/read /dev/mtd0 on development. eg: [root@linux mtd-utils-1.0.0]# mtd_debug erase /dev/mtd0 0x20000 0x40000 Erased 262144 bytes from address 0x00020000 in flash [root@linux mtd-utils-1.0.0]# mtd_debug write /dev/mtd0 0x20000 13 1.img Copied 13 bytes from 1.img to address 0x00020000 in flash [root@linux mtd-utils-1.0.0]# mtd_debug read /dev/mtd0 0x20000 13 2.img Copied 13 bytes from address 0x00020000 in flash to 2.img [root@linux mtd-utils-1.0.0]# cmp -l 1.img 2.img Signed-off-by: Qing Zhang <zhangqing@xxxxxxxxxxx> --- v2: - keep Kconfig and Makefile sorted - make the entire comment a C++ one so things look more intentional - Fix unclear indentation - make conditional statements to improve legibility - Don't use static inline - the core handle message queue - Add a new binding document - Fix probe part mixed pdev and PCI v3: - expose set_cs to the core and let it handle things - replace transfer_one_message to transfer_one - replace spi_alloc_master to devm_spi_alloc_master - split out into prepare/unprepare_message - releases pci regions before unregister master v4: - names used in the manual - rename ls7a_spi_do_transfer to ls7a_spi_setup_transfer - change read the spcr and sper outside of this function - mode configuration moved to prepare instead - remove redundancy code about unprepare/prepare_message - used 0x4 instead of 0x1,WFEMPTY instead of RFEMPTY v5: - remove unnecessary blank lines --- drivers/spi/Kconfig | 7 ++ drivers/spi/Makefile | 1 + drivers/spi/spi-ls7a.c | 280 +++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 288 insertions(+) create mode 100644 drivers/spi/spi-ls7a.c diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index aadaea0..af7c0d4 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -413,6 +413,13 @@ config SPI_LP8841_RTC Say N here unless you plan to run the kernel on an ICP DAS LP-8x4x industrial computer. +config SPI_LS7A + tristate "Loongson LS7A SPI Controller Support" + depends on CPU_LOONGSON64 || COMPILE_TEST + help + This drivers supports the Loongson LS7A SPI controller in master + SPI mode. + config SPI_MPC52xx tristate "Freescale MPC52xx SPI (non-PSC) controller support" depends on PPC_MPC52xx diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index 6fea582..d015cf2 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -61,6 +61,7 @@ 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_LP8841_RTC) += spi-lp8841-rtc.o +obj-$(CONFIG_SPI_LS7A) += spi-ls7a.o obj-$(CONFIG_SPI_MESON_SPICC) += spi-meson-spicc.o obj-$(CONFIG_SPI_MESON_SPIFC) += spi-meson-spifc.o obj-$(CONFIG_SPI_MPC512x_PSC) += spi-mpc512x-psc.o diff --git a/drivers/spi/spi-ls7a.c b/drivers/spi/spi-ls7a.c new file mode 100644 index 0000000..d24b6d91 --- /dev/null +++ b/drivers/spi/spi-ls7a.c @@ -0,0 +1,280 @@ +// SPDX-License-Identifier: GPL-2.0-only +// +// Loongson LS7A SPI Controller driver +// +// Copyright (C) 2020 Loongson Technology Corporation Limited. +// + +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/spi/spi.h> + +/* define spi register */ +#define SPCR 0x00 +#define SPSR 0x01 +#define FIFO 0x02 +#define SPER 0x03 +#define SFC_PARAM 0x04 +#define SFC_SOFTCS 0x05 +#define SFC_TIMING 0x06 + +struct ls7a_spi { + struct spi_master *master; + void __iomem *base; + unsigned int hz; + unsigned int mode; +}; + +static void ls7a_spi_write_reg(struct ls7a_spi *spi, + unsigned char reg, + unsigned char data) +{ + writeb(data, spi->base + reg); +} + +static char ls7a_spi_read_reg(struct ls7a_spi *spi, unsigned char reg) +{ + return readb(spi->base + reg); +} + +static int ls7a_spi_prepare_message(struct spi_master *master, + struct spi_message *msg) +{ + struct ls7a_spi *ls7a_spi; + struct spi_device *spi = msg->spi; + unsigned char val; + + ls7a_spi = spi_master_get_devdata(master); + + if (ls7a_spi->mode != spi->mode) { + val = ls7a_spi_read_reg(ls7a_spi, SPCR); + val &= ~0xc; + if (spi->mode & SPI_CPOL) + val |= 8; + if (spi->mode & SPI_CPHA) + val |= 4; + ls7a_spi_write_reg(ls7a_spi, SPCR, val); + val = ls7a_spi_read_reg(ls7a_spi, SPER); + ls7a_spi_write_reg(ls7a_spi, SPER, val); + ls7a_spi->mode = spi->mode; + } + return 0;I'm sorry that I hadn't review very carefully in V4 and you need to send another new version. In kernel code we usually keep a blank line before the last "return xxx" in a function, and there are several other places with the same problem. Huacai
Thank you again for your reply and suggestions, I will send v6 in the soon. Thanks, -Qing
+} + +static void ls7a_spi_set_cs(struct spi_device *spi, bool enable) +{ + struct ls7a_spi *ls7a_spi; + int cs; + + ls7a_spi = spi_master_get_devdata(spi->master); + + cs = ls7a_spi_read_reg(ls7a_spi, SFC_SOFTCS) & ~(0x11 << spi->chip_select); + + if (!!(spi->mode & SPI_CS_HIGH) == enable) + ls7a_spi_write_reg(ls7a_spi, SFC_SOFTCS, (0x1 << spi->chip_select) | cs); + else + ls7a_spi_write_reg(ls7a_spi, SFC_SOFTCS, (0x11 << spi->chip_select) | cs); +} + +static int ls7a_spi_setup_transfer(struct spi_device *spi, + struct spi_transfer *t) +{ + unsigned int hz; + unsigned int div, div_tmp; + unsigned int bit; + unsigned long clk; + unsigned char val; + unsigned char spcr, sper; + const char rdiv[12] = {0, 1, 4, 2, 3, 5, 6, 7, 8, 9, 10, 11}; + struct ls7a_spi *ls7a_spi; + + ls7a_spi = spi_master_get_devdata(spi->master); + + if (t) { + hz = t->speed_hz; + if (!hz) + hz = spi->max_speed_hz; + } else { + hz = spi->max_speed_hz; + } + + if (hz & (ls7a_spi->hz != hz)) { + clk = 100000000; + + div = DIV_ROUND_UP(clk, 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 = %ld hz = %d div_tmp = %d bit = %d\n", + clk, hz, div_tmp, bit); + + ls7a_spi->hz = hz; + spcr = div_tmp & 3; + sper = (div_tmp >> 2) & 3; + + val = ls7a_spi_read_reg(ls7a_spi, SPCR); + ls7a_spi_write_reg(ls7a_spi, SPCR, (val & ~3) | spcr); + val = ls7a_spi_read_reg(ls7a_spi, SPER); + ls7a_spi_write_reg(ls7a_spi, SPER, (val & ~3) | sper); + } + return 0; +} + +static int ls7a_spi_setup(struct spi_device *spi) +{ + return ls7a_spi_setup_transfer(spi, NULL); +} + +static int ls7a_spi_write_read_8bit(struct spi_device *spi, + const u8 **tx_buf, u8 **rx_buf, + unsigned int num) +{ + struct ls7a_spi *ls7a_spi; + + ls7a_spi = spi_master_get_devdata(spi->master); + + if (tx_buf && *tx_buf) { + ls7a_spi_write_reg(ls7a_spi, FIFO, *((*tx_buf)++)); + + while ((ls7a_spi_read_reg(ls7a_spi, SPSR) & 0x4) == 1) + ; + } else { + ls7a_spi_write_reg(ls7a_spi, FIFO, 0); + + while ((ls7a_spi_read_reg(ls7a_spi, SPSR) & 0x1) == 1) + ; + } + + if (rx_buf && *rx_buf) + *(*rx_buf)++ = ls7a_spi_read_reg(ls7a_spi, FIFO); + else + ls7a_spi_read_reg(ls7a_spi, FIFO); + + return 1; +} + +static unsigned int ls7a_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 (ls7a_spi_write_read_8bit(spi, &tx, &rx, count) < 0) + goto out; + count--; + } while (count); + +out: + return xfer->len - count; +} + +static int ls7a_spi_transfer_one(struct spi_master *master, + struct spi_device *spi, + struct spi_transfer *t) +{ + int status = 0; + + status = ls7a_spi_setup_transfer(spi, t); + if (status < 0) + return status; + + if (t->len) + ls7a_spi_write_read(spi, t); + + return status; +} + +static int ls7a_spi_pci_probe(struct pci_dev *pdev, + const struct pci_device_id *ent) +{ + struct spi_master *master; + struct ls7a_spi *spi; + int ret; + + master = devm_spi_alloc_master(&pdev->dev, sizeof(*spi)); + if (!master) + return -ENOMEM; + + spi = spi_master_get_devdata(master); + ret = pcim_enable_device(pdev); + if (ret) + goto err_free_master; + + ret = pci_request_regions(pdev, "ls7a-spi"); + if (ret) + goto err_free_master; + + spi->base = pcim_iomap(pdev, 0, pci_resource_len(pdev, 0)); + if (!spi->base) { + ret = -EINVAL; + goto err_free_master; + } + ls7a_spi_write_reg(spi, SPCR, 0x51); + ls7a_spi_write_reg(spi, SPER, 0x00); + ls7a_spi_write_reg(spi, SFC_TIMING, 0x01); + ls7a_spi_write_reg(spi, SFC_PARAM, 0x40); + spi->mode = 0; + + master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; + master->set_cs = ls7a_spi_set_cs; + master->prepare_message = ls7a_spi_prepare_message; + master->setup = ls7a_spi_setup; + master->transfer_one = ls7a_spi_transfer_one; + master->bits_per_word_mask = SPI_BPW_MASK(8); + master->num_chipselect = 4; + master->dev.of_node = pdev->dev.of_node; + + spi->master = master; + + pci_set_drvdata(pdev, master); + + ret = spi_register_master(master); + if (ret) + goto err_free_master; + + return 0; + +err_free_master: + pci_release_regions(pdev); + return ret; +} + +static void ls7a_spi_pci_remove(struct pci_dev *pdev) +{ + struct spi_master *master = pci_get_drvdata(pdev); + + spi_unregister_master(master); + pci_release_regions(pdev); +} + +static const struct pci_device_id ls7a_spi_pci_id_table[] = { + { PCI_DEVICE(PCI_VENDOR_ID_LOONGSON, 0x7a0b) }, + { 0, } +}; + +MODULE_DEVICE_TABLE(pci, ls7a_spi_pci_id_table); + +static struct pci_driver ls7a_spi_pci_driver = { + .name = "ls7a-spi", + .id_table = ls7a_spi_pci_id_table, + .probe = ls7a_spi_pci_probe, + .remove = ls7a_spi_pci_remove, +}; + +module_pci_driver(ls7a_spi_pci_driver); + +MODULE_AUTHOR("Juxin Gao <gaojuxin@xxxxxxxxxxx>"); +MODULE_AUTHOR("Qing Zhang <zhangqing@xxxxxxxxxxx>"); +MODULE_DESCRIPTION("Loongson LS7A SPI controller driver"); +MODULE_LICENSE("GPL v2"); -- 2.1.0
