imx-weim.c
/*
* 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>
#include <linux/mfd/syscon.h>
#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
#include <linux/regmap.h>
struct imx_weim_devtype {
unsigned int cs_count;
unsigned int cs_regs_count;
unsigned int cs_stride;
};
static const struct imx_weim_devtype imx1_weim_devtype = {
.cs_count = 6,
.cs_regs_count = 2,
.cs_stride = 0x08,
};
static const struct imx_weim_devtype imx27_weim_devtype = {
.cs_count = 6,
.cs_regs_count = 3,
.cs_stride = 0x10,
};
static const struct imx_weim_devtype imx50_weim_devtype = {
.cs_count = 4,
.cs_regs_count = 6,
.cs_stride = 0x18,
};
static const struct imx_weim_devtype imx51_weim_devtype = {
.cs_count = 6,
.cs_regs_count = 6,
.cs_stride = 0x18,
};
#define MAX_CS_REGS_COUNT 6
static const struct of_device_id weim_id_table[] = {
/* i.MX1/21 */
{ .compatible = "fsl,imx1-weim", .data = &imx1_weim_devtype, },
/* i.MX25/27/31/35 */
{ .compatible = "fsl,imx27-weim", .data = &imx27_weim_devtype, },
/* i.MX50/53/6Q */
{ .compatible = "fsl,imx50-weim", .data = &imx50_weim_devtype, },
{ .compatible = "fsl,imx6q-weim", .data = &imx50_weim_devtype, },
/* i.MX51 */
{ .compatible = "fsl,imx51-weim", .data = &imx51_weim_devtype, },
{ }
};
MODULE_DEVICE_TABLE(of, weim_id_table);
static int __init imx_weim_gpr_setup(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct property *prop;
const __be32 *p;
struct regmap *gpr;
u32 gprvals[4] = {
05, /* CS0(128M) CS1(0M) CS2(0M) CS3(0M) */
033, /* CS0(64M) CS1(64M) CS2(0M) CS3(0M) */
0113, /* CS0(64M) CS1(32M) CS2(32M) CS3(0M) */
01111, /* CS0(32M) CS1(32M) CS2(32M) CS3(32M) */
};
u32 gprval = 0;
u32 val;
int cs = 0;
int i = 0;
gpr = syscon_regmap_lookup_by_phandle(np, "fsl,weim-cs-gpr");
if (IS_ERR(gpr)) {
dev_dbg(&pdev->dev, "failed to find weim-cs-gpr\n");
return 0;
}
of_property_for_each_u32(np, "ranges", prop, p, val) {
if (i % 4 == 0) {
cs = val;
} else if (i % 4 == 3 && val) {
val = (val / SZ_32M) | 1;
gprval |= val << cs * 3;
}
i++;
}
if (i == 0 || i % 4)
goto err;
for (i = 0; i < ARRAY_SIZE(gprvals); i++) {
if (gprval == gprvals[i]) {
/* Found it. Set up IOMUXC_GPR1[11:0] with it. */
regmap_update_bits(gpr, IOMUXC_GPR1, 0xfff, gprval);
return 0;
}
}
err:
dev_err(&pdev->dev, "Invalid 'ranges' configuration\n");
return -EINVAL;
}
/* Parse and set the timing for this device. */
static int __init weim_timing_setup(struct device_node *np, void __iomem *base,
const struct imx_weim_devtype *devtype)
{
u32 cs_idx, value[MAX_CS_REGS_COUNT];
int i, ret;
if (WARN_ON(devtype->cs_regs_count > MAX_CS_REGS_COUNT))
return -EINVAL;
/* get the CS index from this child node's "reg" property. */
ret = of_property_read_u32(np, "reg", &cs_idx);
if (ret)
return ret;
if (cs_idx >= devtype->cs_count)
return -EINVAL;
ret = of_property_read_u32_array(np, "fsl,weim-cs-timing",
value, devtype->cs_regs_count);
if (ret)
return ret;
/* set the timing for WEIM */
for (i = 0; i < devtype->cs_regs_count; i++)
writel(value[i], base + cs_idx * devtype->cs_stride + i * 4);
return 0;
}
static int __init weim_parse_dt(struct platform_device *pdev,
void __iomem *base)
{
const struct of_device_id *of_id = of_match_device(weim_id_table,
&pdev->dev);
const struct imx_weim_devtype *devtype = of_id->data;
struct device_node *child;
int ret, have_child = 0;
if (devtype == &imx50_weim_devtype) {
ret = imx_weim_gpr_setup(pdev);
if (ret)
return ret;
}
for_each_available_child_of_node(pdev->dev.of_node, child) {
ret = weim_timing_setup(child, base, devtype);
if (ret)
dev_warn(&pdev->dev, "%pOF set timing failed.\n",
child);
else
have_child = 1;
}
if (have_child)
ret = of_platform_default_populate(pdev->dev.of_node,
NULL, &pdev->dev);
if (ret)
dev_err(&pdev->dev, "%pOF fail to create devices.\n",
pdev->dev.of_node);
return ret;
}
static int __init weim_probe(struct platform_device *pdev)
{
struct resource *res;
struct clk *clk;
void __iomem *base;
int ret;
/* get the resource */
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(base))
return PTR_ERR(base);
/* get the clock */
clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(clk))
return PTR_ERR(clk);
ret = clk_prepare_enable(clk);
if (ret)
return ret;
/* parse the device node */
ret = weim_parse_dt(pdev, base);
if (ret)
clk_disable_unprepare(clk);
else
dev_info(&pdev->dev, "Driver registered.\n");
return ret;
}
static struct platform_driver weim_driver = {
.driver = {
.name = "imx-weim",
.of_match_table = weim_id_table,
},
};
module_platform_driver_probe(weim_driver, weim_probe);
MODULE_AUTHOR("Freescale Semiconductor Inc.");
MODULE_DESCRIPTION("i.MX EIM Controller Driver");
MODULE_LICENSE("GPL");