diff options
Diffstat (limited to 'kernel/drivers/spi/spi-dw-mmio.c')
-rw-r--r-- | kernel/drivers/spi/spi-dw-mmio.c | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/kernel/drivers/spi/spi-dw-mmio.c b/kernel/drivers/spi/spi-dw-mmio.c new file mode 100644 index 000000000..eb03e1215 --- /dev/null +++ b/kernel/drivers/spi/spi-dw-mmio.c @@ -0,0 +1,145 @@ +/* + * Memory-mapped interface driver for DW SPI Core + * + * Copyright (c) 2010, Octasic semiconductor. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + */ + +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/interrupt.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/spi/spi.h> +#include <linux/scatterlist.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_gpio.h> +#include <linux/of_platform.h> + +#include "spi-dw.h" + +#define DRIVER_NAME "dw_spi_mmio" + +struct dw_spi_mmio { + struct dw_spi dws; + struct clk *clk; +}; + +static int dw_spi_mmio_probe(struct platform_device *pdev) +{ + struct dw_spi_mmio *dwsmmio; + struct dw_spi *dws; + struct resource *mem; + int ret; + int num_cs; + + dwsmmio = devm_kzalloc(&pdev->dev, sizeof(struct dw_spi_mmio), + GFP_KERNEL); + if (!dwsmmio) + return -ENOMEM; + + dws = &dwsmmio->dws; + + /* Get basic io resource and map it */ + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!mem) { + dev_err(&pdev->dev, "no mem resource?\n"); + return -EINVAL; + } + + dws->regs = devm_ioremap_resource(&pdev->dev, mem); + if (IS_ERR(dws->regs)) { + dev_err(&pdev->dev, "SPI region map failed\n"); + return PTR_ERR(dws->regs); + } + + dws->irq = platform_get_irq(pdev, 0); + if (dws->irq < 0) { + dev_err(&pdev->dev, "no irq resource?\n"); + return dws->irq; /* -ENXIO */ + } + + dwsmmio->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(dwsmmio->clk)) + return PTR_ERR(dwsmmio->clk); + ret = clk_prepare_enable(dwsmmio->clk); + if (ret) + return ret; + + dws->bus_num = pdev->id; + + dws->max_freq = clk_get_rate(dwsmmio->clk); + + num_cs = 4; + + if (pdev->dev.of_node) + of_property_read_u32(pdev->dev.of_node, "num-cs", &num_cs); + + dws->num_cs = num_cs; + + if (pdev->dev.of_node) { + int i; + + for (i = 0; i < dws->num_cs; i++) { + int cs_gpio = of_get_named_gpio(pdev->dev.of_node, + "cs-gpios", i); + + if (cs_gpio == -EPROBE_DEFER) { + ret = cs_gpio; + goto out; + } + + if (gpio_is_valid(cs_gpio)) { + ret = devm_gpio_request(&pdev->dev, cs_gpio, + dev_name(&pdev->dev)); + if (ret) + goto out; + } + } + } + + ret = dw_spi_add_host(&pdev->dev, dws); + if (ret) + goto out; + + platform_set_drvdata(pdev, dwsmmio); + return 0; + +out: + clk_disable_unprepare(dwsmmio->clk); + return ret; +} + +static int dw_spi_mmio_remove(struct platform_device *pdev) +{ + struct dw_spi_mmio *dwsmmio = platform_get_drvdata(pdev); + + clk_disable_unprepare(dwsmmio->clk); + dw_spi_remove_host(&dwsmmio->dws); + + return 0; +} + +static const struct of_device_id dw_spi_mmio_of_match[] = { + { .compatible = "snps,dw-apb-ssi", }, + { /* end of table */} +}; +MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match); + +static struct platform_driver dw_spi_mmio_driver = { + .probe = dw_spi_mmio_probe, + .remove = dw_spi_mmio_remove, + .driver = { + .name = DRIVER_NAME, + .of_match_table = dw_spi_mmio_of_match, + }, +}; +module_platform_driver(dw_spi_mmio_driver); + +MODULE_AUTHOR("Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>"); +MODULE_DESCRIPTION("Memory-mapped I/O interface driver for DW SPI Core"); +MODULE_LICENSE("GPL v2"); |