diff options
| -rw-r--r-- | Documentation/devicetree/bindings/spi/spi-xtensa-xtfpga.txt | 9 | ||||
| -rw-r--r-- | MAINTAINERS | 6 | ||||
| -rw-r--r-- | drivers/spi/Kconfig | 13 | ||||
| -rw-r--r-- | drivers/spi/Makefile | 1 | ||||
| -rw-r--r-- | drivers/spi/spi-xilinx.c | 26 | ||||
| -rw-r--r-- | drivers/spi/spi-xtensa-xtfpga.c | 170 |
6 files changed, 205 insertions, 20 deletions
diff --git a/Documentation/devicetree/bindings/spi/spi-xtensa-xtfpga.txt b/Documentation/devicetree/bindings/spi/spi-xtensa-xtfpga.txt new file mode 100644 index 000000000000..b6ebe2bc7041 --- /dev/null +++ b/Documentation/devicetree/bindings/spi/spi-xtensa-xtfpga.txt @@ -0,0 +1,9 @@ +Cadence Xtensa XTFPGA platform SPI controller. + +This simple SPI master controller is built into xtfpga bitstreams and is used +to control daughterboard audio codec. + +Required properties: +- compatible: should be "cdns,xtfpga-spi". +- reg: physical base address of the controller and length of memory mapped + region. diff --git a/MAINTAINERS b/MAINTAINERS index 82640e640f36..338db2514585 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -9782,6 +9782,12 @@ L: linux-serial@vger.kernel.org S: Maintained F: drivers/tty/serial/uartlite.c +XTENSA XTFPGA PLATFORM SUPPORT +M: Max Filippov <jcmvbkbc@gmail.com> +L: linux-xtensa@linux-xtensa.org +S: Maintained +F: drivers/spi/spi-xtensa-xtfpga.c + YAM DRIVER FOR AX.25 M: Jean-Paul Roubelat <jpr@f6fbb.org> L: linux-hams@vger.kernel.org diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index 756b5b3ca200..efe1960af2b3 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -538,6 +538,19 @@ config SPI_XILINX Or for the DS570, see "XPS Serial Peripheral Interface (SPI) (v2.00b)" +config SPI_XTENSA_XTFPGA + tristate "Xtensa SPI controller for xtfpga" + depends on (XTENSA && XTENSA_PLATFORM_XTFPGA) || COMPILE_TEST + select SPI_BITBANG + help + SPI driver for xtfpga SPI master controller. + + This simple SPI master controller is built into xtfpga bitstreams + and is used to control daughterboard audio codec. It always transfers + 16 bit words in SPI mode 0, automatically asserting CS on transfer + start and deasserting on end. + + config SPI_NUC900 tristate "Nuvoton NUC900 series SPI" depends on ARCH_W90X900 diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index e245b94d07d8..bd792669e563 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -81,3 +81,4 @@ obj-$(CONFIG_SPI_TOPCLIFF_PCH) += spi-topcliff-pch.o obj-$(CONFIG_SPI_TXX9) += spi-txx9.o obj-$(CONFIG_SPI_XCOMM) += spi-xcomm.o obj-$(CONFIG_SPI_XILINX) += spi-xilinx.o +obj-$(CONFIG_SPI_XTENSA_XTFPGA) += spi-xtensa-xtfpga.o diff --git a/drivers/spi/spi-xilinx.c b/drivers/spi/spi-xilinx.c index e6cd1112ae40..a3b0b9944bf0 100644 --- a/drivers/spi/spi-xilinx.c +++ b/drivers/spi/spi-xilinx.c @@ -87,10 +87,10 @@ struct xilinx_spi { const u8 *tx_ptr; /* pointer in the Rx buffer */ int remaining_bytes; /* the number of bytes left to transfer */ u8 bits_per_word; - unsigned int (*read_fn) (void __iomem *); - void (*write_fn) (u32, void __iomem *); - void (*tx_fn) (struct xilinx_spi *); - void (*rx_fn) (struct xilinx_spi *); + unsigned int (*read_fn)(void __iomem *); + void (*write_fn)(u32, void __iomem *); + void (*tx_fn)(struct xilinx_spi *); + void (*rx_fn)(struct xilinx_spi *); }; static void xspi_write32(u32 val, void __iomem *addr) @@ -208,26 +208,11 @@ static void xilinx_spi_chipselect(struct spi_device *spi, int is_on) } /* spi_bitbang requires custom setup_transfer() to be defined if there is a - * custom txrx_bufs(). We have nothing to setup here as the SPI IP block - * supports 8 or 16 bits per word which cannot be changed in software. - * SPI clock can't be changed in software either. - * Check for correct bits per word. Chip select delay calculations could be - * added here as soon as bitbang_work() can be made aware of the delay value. + * custom txrx_bufs(). */ static int xilinx_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t) { - struct xilinx_spi *xspi = spi_master_get_devdata(spi->master); - u8 bits_per_word; - - bits_per_word = (t && t->bits_per_word) - ? t->bits_per_word : spi->bits_per_word; - if (bits_per_word != xspi->bits_per_word) { - dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n", - __func__, bits_per_word); - return -EINVAL; - } - return 0; } @@ -406,6 +391,7 @@ static int xilinx_spi_probe(struct platform_device *pdev) xspi->write_fn = xspi_write32_be; } + master->bits_per_word_mask = SPI_BPW_MASK(bits_per_word); xspi->bits_per_word = bits_per_word; if (xspi->bits_per_word == 8) { xspi->tx_fn = xspi_tx8; diff --git a/drivers/spi/spi-xtensa-xtfpga.c b/drivers/spi/spi-xtensa-xtfpga.c new file mode 100644 index 000000000000..41e158187f9d --- /dev/null +++ b/drivers/spi/spi-xtensa-xtfpga.c @@ -0,0 +1,170 @@ +/* + * Xtensa xtfpga SPI controller driver + * + * Copyright (c) 2014 Cadence Design Systems Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/spi/spi.h> +#include <linux/spi/spi_bitbang.h> + +#define XTFPGA_SPI_NAME "xtfpga_spi" + +#define XTFPGA_SPI_START 0x0 +#define XTFPGA_SPI_BUSY 0x4 +#define XTFPGA_SPI_DATA 0x8 + +#define BUSY_WAIT_US 100 + +struct xtfpga_spi { + struct spi_bitbang bitbang; + void __iomem *regs; + u32 data; + unsigned data_sz; +}; + +static inline void xtfpga_spi_write32(const struct xtfpga_spi *spi, + unsigned addr, u32 val) +{ + iowrite32(val, spi->regs + addr); +} + +static inline unsigned int xtfpga_spi_read32(const struct xtfpga_spi *spi, + unsigned addr) +{ + return ioread32(spi->regs + addr); +} + +static inline void xtfpga_spi_wait_busy(struct xtfpga_spi *xspi) +{ + unsigned i; + for (i = 0; xtfpga_spi_read32(xspi, XTFPGA_SPI_BUSY) && + i < BUSY_WAIT_US; ++i) + udelay(1); + WARN_ON_ONCE(i == BUSY_WAIT_US); +} + +static u32 xtfpga_spi_txrx_word(struct spi_device *spi, unsigned nsecs, + u32 v, u8 bits) +{ + struct xtfpga_spi *xspi = spi_master_get_devdata(spi->master); + + xspi->data = (xspi->data << bits) | (v & GENMASK(bits - 1, 0)); + xspi->data_sz += bits; + if (xspi->data_sz >= 16) { + xtfpga_spi_write32(xspi, XTFPGA_SPI_DATA, + xspi->data >> (xspi->data_sz - 16)); + xspi->data_sz -= 16; + xtfpga_spi_write32(xspi, XTFPGA_SPI_START, 1); + xtfpga_spi_wait_busy(xspi); + xtfpga_spi_write32(xspi, XTFPGA_SPI_START, 0); + } + + return 0; +} + +static void xtfpga_spi_chipselect(struct spi_device *spi, int is_on) +{ + struct xtfpga_spi *xspi = spi_master_get_devdata(spi->master); + + WARN_ON(xspi->data_sz != 0); + xspi->data_sz = 0; +} + +static int xtfpga_spi_probe(struct platform_device *pdev) +{ + struct xtfpga_spi *xspi; + struct resource *mem; + int ret; + struct spi_master *master; + + master = spi_alloc_master(&pdev->dev, sizeof(struct xtfpga_spi)); + if (!master) + return -ENOMEM; + + master->flags = SPI_MASTER_NO_RX; + master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 16); + master->bus_num = pdev->dev.id; + master->dev.of_node = pdev->dev.of_node; + + xspi = spi_master_get_devdata(master); + xspi->bitbang.master = master; + xspi->bitbang.chipselect = xtfpga_spi_chipselect; + xspi->bitbang.txrx_word[SPI_MODE_0] = xtfpga_spi_txrx_word; + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!mem) { + dev_err(&pdev->dev, "No memory resource\n"); + ret = -ENODEV; + goto err; + } + xspi->regs = devm_ioremap_resource(&pdev->dev, mem); + if (IS_ERR(xspi->regs)) { + ret = PTR_ERR(xspi->regs); + goto err; + } + + xtfpga_spi_write32(xspi, XTFPGA_SPI_START, 0); + usleep_range(1000, 2000); + if (xtfpga_spi_read32(xspi, XTFPGA_SPI_BUSY)) { + dev_err(&pdev->dev, "Device stuck in busy state\n"); + ret = -EBUSY; + goto err; + } + + ret = spi_bitbang_start(&xspi->bitbang); + if (ret < 0) { + dev_err(&pdev->dev, "spi_bitbang_start failed\n"); + goto err; + } + + platform_set_drvdata(pdev, master); + return 0; +err: + spi_master_put(master); + return ret; +} + +static int xtfpga_spi_remove(struct platform_device *pdev) +{ + struct spi_master *master = platform_get_drvdata(pdev); + struct xtfpga_spi *xspi = spi_master_get_devdata(master); + + spi_bitbang_stop(&xspi->bitbang); + spi_master_put(master); + + return 0; +} + +MODULE_ALIAS("platform:" XTFPGA_SPI_NAME); + +#ifdef CONFIG_OF +static const struct of_device_id xtfpga_spi_of_match[] = { + { .compatible = "cdns,xtfpga-spi", }, + {} +}; +MODULE_DEVICE_TABLE(of, xtfpga_spi_of_match); +#endif + +static struct platform_driver xtfpga_spi_driver = { + .probe = xtfpga_spi_probe, + .remove = xtfpga_spi_remove, + .driver = { + .name = XTFPGA_SPI_NAME, + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(xtfpga_spi_of_match), + }, +}; +module_platform_driver(xtfpga_spi_driver); + +MODULE_AUTHOR("Max Filippov <jcmvbkbc@gmail.com>"); +MODULE_DESCRIPTION("xtensa xtfpga SPI driver"); +MODULE_LICENSE("GPL"); |