139 строки
3.0 KiB
C
139 строки
3.0 KiB
C
/*
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* EIM driver for Freescale's i.MX chips
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*
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* Copyright (C) 2013 Freescale Semiconductor, Inc.
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*
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* This file is licensed under the terms of the GNU General Public
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* License version 2. This program is licensed "as is" without any
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* warranty of any kind, whether express or implied.
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*/
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#include <linux/module.h>
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#include <linux/clk.h>
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#include <linux/io.h>
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#include <linux/of_device.h>
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struct imx_weim {
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void __iomem *base;
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struct clk *clk;
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};
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static const struct of_device_id weim_id_table[] = {
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{ .compatible = "fsl,imx6q-weim", },
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{}
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};
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MODULE_DEVICE_TABLE(of, weim_id_table);
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#define CS_TIMING_LEN 6
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#define CS_REG_RANGE 0x18
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/* Parse and set the timing for this device. */
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static int
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weim_timing_setup(struct platform_device *pdev, struct device_node *np)
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{
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struct imx_weim *weim = platform_get_drvdata(pdev);
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u32 value[CS_TIMING_LEN];
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u32 cs_idx;
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int ret;
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int i;
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/* get the CS index from this child node's "reg" property. */
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ret = of_property_read_u32(np, "reg", &cs_idx);
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if (ret)
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return ret;
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/* The weim has four chip selects. */
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if (cs_idx > 3)
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return -EINVAL;
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ret = of_property_read_u32_array(np, "fsl,weim-cs-timing",
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value, CS_TIMING_LEN);
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if (ret)
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return ret;
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/* set the timing for WEIM */
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for (i = 0; i < CS_TIMING_LEN; i++)
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writel(value[i], weim->base + cs_idx * CS_REG_RANGE + i * 4);
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return 0;
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}
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static int weim_parse_dt(struct platform_device *pdev)
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{
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struct device_node *child;
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int ret;
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for_each_child_of_node(pdev->dev.of_node, child) {
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if (!child->name)
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continue;
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ret = weim_timing_setup(pdev, child);
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if (ret) {
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dev_err(&pdev->dev, "%s set timing failed.\n",
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child->full_name);
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return ret;
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}
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}
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ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
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if (ret)
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dev_err(&pdev->dev, "%s fail to create devices.\n",
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pdev->dev.of_node->full_name);
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return ret;
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}
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static int weim_probe(struct platform_device *pdev)
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{
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struct imx_weim *weim;
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struct resource *res;
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int ret = -EINVAL;
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weim = devm_kzalloc(&pdev->dev, sizeof(*weim), GFP_KERNEL);
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if (!weim) {
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ret = -ENOMEM;
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goto weim_err;
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}
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platform_set_drvdata(pdev, weim);
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/* get the resource */
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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weim->base = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(weim->base)) {
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ret = PTR_ERR(weim->base);
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goto weim_err;
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}
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/* get the clock */
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weim->clk = devm_clk_get(&pdev->dev, NULL);
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if (IS_ERR(weim->clk))
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goto weim_err;
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ret = clk_prepare_enable(weim->clk);
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if (ret)
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goto weim_err;
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/* parse the device node */
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ret = weim_parse_dt(pdev);
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if (ret) {
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clk_disable_unprepare(weim->clk);
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goto weim_err;
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}
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dev_info(&pdev->dev, "WEIM driver registered.\n");
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return 0;
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weim_err:
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return ret;
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}
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static struct platform_driver weim_driver = {
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.driver = {
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.name = "imx-weim",
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.of_match_table = weim_id_table,
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},
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.probe = weim_probe,
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};
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module_platform_driver(weim_driver);
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MODULE_AUTHOR("Freescale Semiconductor Inc.");
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MODULE_DESCRIPTION("i.MX EIM Controller Driver");
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MODULE_LICENSE("GPL");
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