Memory-mapped dw_spi driver

Adds a memory-mapped I/O dw_spi platform device.

Signed-off-by: Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 148 insertions, 0 deletions

diff --git a/drivers/spi/dw_spi_mmio.c b/drivers/spi/dw_spi_mmio.c
new file mode 100644
index 000000000000..26c4b49bdd5c
--- /dev/null
+++ b/drivers/spi/dw_spi_mmio.c
@@ -0,0 +1,148 @@
+/*
+ * dw_spi_mmio.c - 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/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/spi/dw_spi.h>
+#include <linux/spi/spi.h>
+
+#define DRIVER_NAME "dw_spi_mmio"
+
+struct dw_spi_mmio {
+        struct dw_spi   dws;
+        struct clk              *clk;
+};
+
+static int __devinit dw_spi_mmio_probe(struct platform_device *pdev)
+{
+        struct dw_spi_mmio *dwsmmio;
+        struct dw_spi *dws;
+        struct resource *mem, *ioarea;
+        int ret;
+
+        dwsmmio = kzalloc(sizeof(struct dw_spi_mmio), GFP_KERNEL);
+        if (!dwsmmio) {
+                ret = -ENOMEM;
+                goto err_end;
+        }
+
+        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");
+                ret = -EINVAL;
+                goto err_kfree;
+        }
+
+        ioarea = request_mem_region(mem->start, resource_size(mem),
+                        pdev->name);
+        if (!ioarea) {
+                dev_err(&pdev->dev, "SPI region already claimed\n");
+                ret = -EBUSY;
+                goto err_kfree;
+        }
+
+        dws->regs = ioremap_nocache(mem->start, resource_size(mem));
+        if (!dws->regs) {
+                dev_err(&pdev->dev, "SPI region already mapped\n");
+                ret = -ENOMEM;
+                goto err_release_reg;
+        }
+
+        dws->irq = platform_get_irq(pdev, 0);
+        if (dws->irq < 0) {
+                dev_err(&pdev->dev, "no irq resource?\n");
+                ret = dws->irq; /* -ENXIO */
+                goto err_unmap;
+        }
+
+        dwsmmio->clk = clk_get(&pdev->dev, NULL);
+        if (!dwsmmio->clk) {
+                ret = -ENODEV;
+                goto err_irq;
+        }
+        clk_enable(dwsmmio->clk);
+
+        dws->parent_dev = &pdev->dev;
+        dws->bus_num = 0;
+        dws->num_cs = 4;
+        dws->max_freq = clk_get_rate(dwsmmio->clk);
+
+        ret = dw_spi_add_host(dws);
+        if (ret)
+                goto err_clk;
+
+        platform_set_drvdata(pdev, dwsmmio);
+        return 0;
+
+err_clk:
+        clk_disable(dwsmmio->clk);
+        clk_put(dwsmmio->clk);
+        dwsmmio->clk = NULL;
+err_irq:
+        free_irq(dws->irq, dws);
+err_unmap:
+        iounmap(dws->regs);
+err_release_reg:
+        release_mem_region(mem->start, resource_size(mem));
+err_kfree:
+        kfree(dwsmmio);
+err_end:
+        return ret;
+}
+
+static int __devexit dw_spi_mmio_remove(struct platform_device *pdev)
+{
+        struct dw_spi_mmio *dwsmmio = platform_get_drvdata(pdev);
+        struct resource *mem;
+
+        platform_set_drvdata(pdev, NULL);
+
+        clk_disable(dwsmmio->clk);
+        clk_put(dwsmmio->clk);
+        dwsmmio->clk = NULL;
+
+        free_irq(dwsmmio->dws.irq, &dwsmmio->dws);
+        dw_spi_remove_host(&dwsmmio->dws);
+        iounmap(dwsmmio->dws.regs);
+        kfree(dwsmmio);
+
+        mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        release_mem_region(mem->start, resource_size(mem));
+        return 0;
+}
+
+static struct platform_driver dw_spi_mmio_driver = {
+        .remove         = __devexit_p(dw_spi_mmio_remove),
+        .driver         = {
+                .name   = DRIVER_NAME,
+                .owner  = THIS_MODULE,
+        },
+};
+
+static int __init dw_spi_mmio_init(void)
+{
+        return platform_driver_probe(&dw_spi_mmio_driver, dw_spi_mmio_probe);
+}
+
+static void __exit dw_spi_mmio_exit(void)
+{
+        platform_driver_unregister(&dw_spi_mmio_driver);
+}
+
+module_init(dw_spi_mmio_init);
+module_exit(dw_spi_mmio_exit);
+
+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");