[PATCH v3 5/5] mmc: sdhci-of-aspeed: Assert/Deassert reset signal before probing eMMC
From: Steven Lee
Date: Thu May 06 2021 - 06:08:24 EST
For cleaning up the AST2600 eMMC controller, the reset signal should be
asserted and deasserted before it is probed.
Signed-off-by: Steven Lee <steven_lee@xxxxxxxxxxxxxx>
---
drivers/mmc/host/sdhci-of-aspeed.c | 49 ++++++++++++++++++++++++------
1 file changed, 40 insertions(+), 9 deletions(-)
diff --git a/drivers/mmc/host/sdhci-of-aspeed.c b/drivers/mmc/host/sdhci-of-aspeed.c
index 4979f98ffb52..8ef06f32abff 100644
--- a/drivers/mmc/host/sdhci-of-aspeed.c
+++ b/drivers/mmc/host/sdhci-of-aspeed.c
@@ -13,6 +13,7 @@
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
+#include <linux/reset.h>
#include <linux/spinlock.h>
#include "sdhci-pltfm.h"
@@ -36,9 +37,16 @@
/* SDIO{14,24} */
#define ASPEED_SDC_CAP2_SDR104 (1 * 32 + 1)
+#define PROBE_AFTER_ASSET_DEASSERT 0x1
+
+struct aspeed_sdc_info {
+ u32 flag;
+};
+
struct aspeed_sdc {
struct clk *clk;
struct resource *res;
+ struct reset_control *rst;
spinlock_t lock;
void __iomem *regs;
@@ -78,6 +86,10 @@ struct aspeed_sdhci {
};
+struct aspeed_sdc_info ast2600_sdc_info = {
+ .flag = PROBE_AFTER_ASSET_DEASSERT
+};
+
/*
* The function sets the mirror register for updating
* capbilities of the current slot.
@@ -533,11 +545,22 @@ static struct platform_driver aspeed_sdhci_driver = {
.remove = aspeed_sdhci_remove,
};
+static const struct of_device_id aspeed_sdc_of_match[] = {
+ { .compatible = "aspeed,ast2400-sd-controller", },
+ { .compatible = "aspeed,ast2500-sd-controller", },
+ { .compatible = "aspeed,ast2600-sd-controller", .data = &ast2600_sdc_info},
+ { }
+};
+
+MODULE_DEVICE_TABLE(of, aspeed_sdc_of_match);
+
static int aspeed_sdc_probe(struct platform_device *pdev)
{
struct device_node *parent, *child;
struct aspeed_sdc *sdc;
+ const struct of_device_id *match = NULL;
+ const struct aspeed_sdc_info *info = NULL;
int ret;
sdc = devm_kzalloc(&pdev->dev, sizeof(*sdc), GFP_KERNEL);
@@ -546,6 +569,23 @@ static int aspeed_sdc_probe(struct platform_device *pdev)
spin_lock_init(&sdc->lock);
+ match = of_match_device(aspeed_sdc_of_match, &pdev->dev);
+ if (!match)
+ return -ENODEV;
+
+ if (match->data)
+ info = match->data;
+
+ if (info) {
+ if (info->flag & PROBE_AFTER_ASSET_DEASSERT) {
+ sdc->rst = devm_reset_control_get(&pdev->dev, NULL);
+ if (!IS_ERR(sdc->rst)) {
+ reset_control_assert(sdc->rst);
+ reset_control_deassert(sdc->rst);
+ }
+ }
+ }
+
sdc->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(sdc->clk))
return PTR_ERR(sdc->clk);
@@ -593,15 +633,6 @@ static int aspeed_sdc_remove(struct platform_device *pdev)
return 0;
}
-static const struct of_device_id aspeed_sdc_of_match[] = {
- { .compatible = "aspeed,ast2400-sd-controller", },
- { .compatible = "aspeed,ast2500-sd-controller", },
- { .compatible = "aspeed,ast2600-sd-controller", },
- { }
-};
-
-MODULE_DEVICE_TABLE(of, aspeed_sdc_of_match);
-
static struct platform_driver aspeed_sdc_driver = {
.driver = {
.name = "sd-controller-aspeed",
--
2.17.1