diff options
Diffstat (limited to 'drivers/bus/imx-weim.c')
| -rw-r--r-- | drivers/bus/imx-weim.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/drivers/bus/imx-weim.c b/drivers/bus/imx-weim.c new file mode 100644 index 000000000000..349f14e886b7 --- /dev/null +++ b/drivers/bus/imx-weim.c @@ -0,0 +1,138 @@ +/* + * EIM driver for Freescale's i.MX chips + * + * Copyright (C) 2013 Freescale Semiconductor, Inc. + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ +#include <linux/module.h> +#include <linux/clk.h> +#include <linux/io.h> +#include <linux/of_device.h> + +struct imx_weim { + void __iomem *base; + struct clk *clk; +}; + +static const struct of_device_id weim_id_table[] = { + { .compatible = "fsl,imx6q-weim", }, + {} +}; +MODULE_DEVICE_TABLE(of, weim_id_table); + +#define CS_TIMING_LEN 6 +#define CS_REG_RANGE 0x18 + +/* Parse and set the timing for this device. */ +static int +weim_timing_setup(struct platform_device *pdev, struct device_node *np) +{ + struct imx_weim *weim = platform_get_drvdata(pdev); + u32 value[CS_TIMING_LEN]; + u32 cs_idx; + int ret; + int i; + + /* get the CS index from this child node's "reg" property. */ + ret = of_property_read_u32(np, "reg", &cs_idx); + if (ret) + return ret; + + /* The weim has four chip selects. */ + if (cs_idx > 3) + return -EINVAL; + + ret = of_property_read_u32_array(np, "fsl,weim-cs-timing", + value, CS_TIMING_LEN); + if (ret) + return ret; + + /* set the timing for WEIM */ + for (i = 0; i < CS_TIMING_LEN; i++) + writel(value[i], weim->base + cs_idx * CS_REG_RANGE + i * 4); + return 0; +} + +static int weim_parse_dt(struct platform_device *pdev) +{ + struct device_node *child; + int ret; + + for_each_child_of_node(pdev->dev.of_node, child) { + if (!child->name) + continue; + + ret = weim_timing_setup(pdev, child); + if (ret) { + dev_err(&pdev->dev, "%s set timing failed.\n", + child->full_name); + return ret; + } + } + + ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev); + if (ret) + dev_err(&pdev->dev, "%s fail to create devices.\n", + pdev->dev.of_node->full_name); + return ret; +} + +static int weim_probe(struct platform_device *pdev) +{ + struct imx_weim *weim; + struct resource *res; + int ret = -EINVAL; + + weim = devm_kzalloc(&pdev->dev, sizeof(*weim), GFP_KERNEL); + if (!weim) { + ret = -ENOMEM; + goto weim_err; + } + platform_set_drvdata(pdev, weim); + + /* get the resource */ + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + weim->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(weim->base)) { + ret = PTR_ERR(weim->base); + goto weim_err; + } + + /* get the clock */ + weim->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(weim->clk)) + goto weim_err; + + ret = clk_prepare_enable(weim->clk); + if (ret) + goto weim_err; + + /* parse the device node */ + ret = weim_parse_dt(pdev); + if (ret) { + clk_disable_unprepare(weim->clk); + goto weim_err; + } + + dev_info(&pdev->dev, "WEIM driver registered.\n"); + return 0; + +weim_err: + return ret; +} + +static struct platform_driver weim_driver = { + .driver = { + .name = "imx-weim", + .of_match_table = weim_id_table, + }, + .probe = weim_probe, +}; + +module_platform_driver(weim_driver); +MODULE_AUTHOR("Freescale Semiconductor Inc."); +MODULE_DESCRIPTION("i.MX EIM Controller Driver"); +MODULE_LICENSE("GPL"); |