linux/drivers/bus/imx-weim.c

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/*
* 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;
unsigned int wcr_offset;
unsigned int wcr_bcm;
unsigned int wcr_cont_bclk;
};
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,
.wcr_offset = 0x90,
.wcr_bcm = BIT(0),
.wcr_cont_bclk = BIT(3),
};
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
#define MAX_CS_COUNT 6
#define OF_REG_SIZE 3
struct cs_timing {
bool is_applied;
u32 regs[MAX_CS_REGS_COUNT];
};
struct cs_timing_state {
struct cs_timing cs[MAX_CS_COUNT];
};
struct weim_priv {
void __iomem *base;
struct cs_timing_state timing_state;
};
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 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 weim_timing_setup(struct device *dev, struct device_node *np,
const struct imx_weim_devtype *devtype)
{
u32 cs_idx, value[MAX_CS_REGS_COUNT];
int i, ret;
int reg_idx, num_regs;
struct cs_timing *cst;
struct weim_priv *priv;
struct cs_timing_state *ts;
void __iomem *base;
if (WARN_ON(devtype->cs_regs_count > MAX_CS_REGS_COUNT))
return -EINVAL;
if (WARN_ON(devtype->cs_count > MAX_CS_COUNT))
return -EINVAL;
priv = dev_get_drvdata(dev);
base = priv->base;
ts = &priv->timing_state;
ret = of_property_read_u32_array(np, "fsl,weim-cs-timing",
value, devtype->cs_regs_count);
if (ret)
return ret;
/*
* the child node's "reg" property may contain multiple address ranges,
* extract the chip select for each.
*/
num_regs = of_property_count_elems_of_size(np, "reg", OF_REG_SIZE);
if (num_regs < 0)
return num_regs;
if (!num_regs)
return -EINVAL;
for (reg_idx = 0; reg_idx < num_regs; reg_idx++) {
/* get the CS index from this child node's "reg" property. */
ret = of_property_read_u32_index(np, "reg",
reg_idx * OF_REG_SIZE, &cs_idx);
if (ret)
break;
if (cs_idx >= devtype->cs_count)
return -EINVAL;
/* prevent re-configuring a CS that's already been configured */
cst = &ts->cs[cs_idx];
if (cst->is_applied && memcmp(value, cst->regs,
devtype->cs_regs_count * sizeof(u32))) {
dev_err(dev, "fsl,weim-cs-timing conflict on %pOF", np);
return -EINVAL;
}
/* 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);
if (!cst->is_applied) {
cst->is_applied = true;
memcpy(cst->regs, value,
devtype->cs_regs_count * sizeof(u32));
}
}
return 0;
}
static int weim_parse_dt(struct platform_device *pdev)
{
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;
struct weim_priv *priv;
void __iomem *base;
u32 reg;
if (devtype == &imx50_weim_devtype) {
ret = imx_weim_gpr_setup(pdev);
if (ret)
return ret;
}
priv = dev_get_drvdata(&pdev->dev);
base = priv->base;
if (of_property_read_bool(pdev->dev.of_node, "fsl,burst-clk-enable")) {
if (devtype->wcr_bcm) {
reg = readl(base + devtype->wcr_offset);
reg |= devtype->wcr_bcm;
if (of_property_read_bool(pdev->dev.of_node,
"fsl,continuous-burst-clk")) {
if (devtype->wcr_cont_bclk) {
reg |= devtype->wcr_cont_bclk;
} else {
dev_err(&pdev->dev,
"continuous burst clk not supported.\n");
return -EINVAL;
}
}
writel(reg, base + devtype->wcr_offset);
} else {
dev_err(&pdev->dev, "burst clk mode not supported.\n");
return -EINVAL;
}
}
for_each_available_child_of_node(pdev->dev.of_node, child) {
ret = weim_timing_setup(&pdev->dev, child, 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 weim_probe(struct platform_device *pdev)
{
struct weim_priv *priv;
struct resource *res;
struct clk *clk;
void __iomem *base;
int ret;
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
/* 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);
priv->base = base;
dev_set_drvdata(&pdev->dev, priv);
/* 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);
if (ret)
clk_disable_unprepare(clk);
else
dev_info(&pdev->dev, "Driver registered.\n");
return ret;
}
#if IS_ENABLED(CONFIG_OF_DYNAMIC)
static int of_weim_notify(struct notifier_block *nb, unsigned long action,
void *arg)
{
const struct imx_weim_devtype *devtype;
struct of_reconfig_data *rd = arg;
const struct of_device_id *of_id;
struct platform_device *pdev;
int ret = NOTIFY_OK;
switch (of_reconfig_get_state_change(action, rd)) {
case OF_RECONFIG_CHANGE_ADD:
of_id = of_match_node(weim_id_table, rd->dn->parent);
if (!of_id)
return NOTIFY_OK; /* not for us */
devtype = of_id->data;
pdev = of_find_device_by_node(rd->dn->parent);
if (!pdev) {
pr_err("%s: could not find platform device for '%pOF'\n",
__func__, rd->dn->parent);
return notifier_from_errno(-EINVAL);
}
if (weim_timing_setup(&pdev->dev, rd->dn, devtype))
dev_warn(&pdev->dev,
"Failed to setup timing for '%pOF'\n", rd->dn);
if (!of_node_check_flag(rd->dn, OF_POPULATED)) {
treewide: Fix probing of devices in DT overlays When loading a DT overlay that creates a device, the device is not probed, unless the DT overlay is unloaded and reloaded again. After the recent refactoring to improve fw_devlink, it no longer depends on the "compatible" property to identify which device tree nodes will become struct devices. fw_devlink now picks up dangling consumers (consumers pointing to descendent device tree nodes of a device that aren't converted to child devices) when a device is successfully bound to a driver. See __fw_devlink_pickup_dangling_consumers(). However, during DT overlay, a device's device tree node can have sub-nodes added/removed without unbinding/rebinding the driver. This difference in behavior between the normal device instantiation and probing flow vs. the DT overlay flow has a bunch of implications that are pointed out elsewhere[1]. One of them is that the fw_devlink logic to pick up dangling consumers is never exercised. This patch solves the fw_devlink issue by marking all DT nodes added by DT overlays with FWNODE_FLAG_NOT_DEVICE (fwnode that won't become device), and by clearing the flag when a struct device is actually created for the DT node. This way, fw_devlink knows not to have consumers waiting on these newly added DT nodes, and to propagate the dependency to an ancestor DT node that has the corresponding struct device. Based on a patch by Saravana Kannan, which covered only platform and spi devices. [1] https://lore.kernel.org/r/CAGETcx_bkuFaLCiPrAWCPQz+w79ccDp6=9e881qmK=vx3hBMyg@mail.gmail.com Fixes: 4a032827daa89350 ("of: property: Simplify of_link_to_phandle()") Link: https://lore.kernel.org/r/CAGETcx_+rhHvaC_HJXGrr5_WAd2+k5f=rWYnkCZ6z5bGX-wj4w@mail.gmail.com Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C Acked-by: Shawn Guo <shawnguo@kernel.org> Acked-by: Saravana Kannan <saravanak@google.com> Tested-by: Ivan Bornyakov <i.bornyakov@metrotek.ru> Link: https://lore.kernel.org/r/e1fa546682ea4c8474ff997ab6244c5e11b6f8bc.1680182615.git.geert+renesas@glider.be Signed-off-by: Rob Herring <robh@kernel.org>
2023-03-30 21:26:13 +08:00
/*
* Clear the flag before adding the device so that
* fw_devlink doesn't skip adding consumers to this
* device.
*/
rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
if (!of_platform_device_create(rd->dn, NULL, &pdev->dev)) {
dev_err(&pdev->dev,
"Failed to create child device '%pOF'\n",
rd->dn);
ret = notifier_from_errno(-EINVAL);
}
}
platform_device_put(pdev);
break;
case OF_RECONFIG_CHANGE_REMOVE:
if (!of_node_check_flag(rd->dn, OF_POPULATED))
return NOTIFY_OK; /* device already destroyed */
of_id = of_match_node(weim_id_table, rd->dn->parent);
if (!of_id)
return NOTIFY_OK; /* not for us */
pdev = of_find_device_by_node(rd->dn);
if (!pdev) {
pr_err("Could not find platform device for '%pOF'\n",
rd->dn);
ret = notifier_from_errno(-EINVAL);
} else {
of_platform_device_destroy(&pdev->dev, NULL);
platform_device_put(pdev);
}
break;
default:
break;
}
return ret;
}
static struct notifier_block weim_of_notifier = {
.notifier_call = of_weim_notify,
};
#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
static struct platform_driver weim_driver = {
.driver = {
.name = "imx-weim",
.of_match_table = weim_id_table,
},
.probe = weim_probe,
};
static int __init weim_init(void)
{
#if IS_ENABLED(CONFIG_OF_DYNAMIC)
WARN_ON(of_reconfig_notifier_register(&weim_of_notifier));
#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
return platform_driver_register(&weim_driver);
}
module_init(weim_init);
static void __exit weim_exit(void)
{
#if IS_ENABLED(CONFIG_OF_DYNAMIC)
of_reconfig_notifier_unregister(&weim_of_notifier);
#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
return platform_driver_unregister(&weim_driver);
}
module_exit(weim_exit);
MODULE_AUTHOR("Freescale Semiconductor Inc.");
MODULE_DESCRIPTION("i.MX EIM Controller Driver");
MODULE_LICENSE("GPL");