Re: [PATCH V5] mmc: sdhci-msm: Reset GCC_SDCC_BCR register for SDHC
From: Sajida Bhanu (Temp)
Date: Thu May 05 2022 - 05:17:27 EST
On 5/4/2022 4:07 PM, Ulf Hansson wrote:
On Wed, 27 Apr 2022 at 16:42, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote:
On Sun, 24 Apr 2022 at 18:02, Shaik Sajida Bhanu
<quic_c_sbhanu@xxxxxxxxxxx> wrote:
Reset GCC_SDCC_BCR register before every fresh initilazation. This will
reset whole SDHC-msm controller, clears the previous power control
states and avoids, software reset timeout issues as below.
[ 5.458061][ T262] mmc1: Reset 0x1 never completed.
[ 5.462454][ T262] mmc1: sdhci: ============ SDHCI REGISTER DUMP ===========
[ 5.469065][ T262] mmc1: sdhci: Sys addr: 0x00000000 | Version: 0x00007202
[ 5.475688][ T262] mmc1: sdhci: Blk size: 0x00000000 | Blk cnt: 0x00000000
[ 5.482315][ T262] mmc1: sdhci: Argument: 0x00000000 | Trn mode: 0x00000000
[ 5.488927][ T262] mmc1: sdhci: Present: 0x01f800f0 | Host ctl: 0x00000000
[ 5.495539][ T262] mmc1: sdhci: Power: 0x00000000 | Blk gap: 0x00000000
[ 5.502162][ T262] mmc1: sdhci: Wake-up: 0x00000000 | Clock: 0x00000003
[ 5.508768][ T262] mmc1: sdhci: Timeout: 0x00000000 | Int stat: 0x00000000
[ 5.515381][ T262] mmc1: sdhci: Int enab: 0x00000000 | Sig enab: 0x00000000
[ 5.521996][ T262] mmc1: sdhci: ACmd stat: 0x00000000 | Slot int: 0x00000000
[ 5.528607][ T262] mmc1: sdhci: Caps: 0x362dc8b2 | Caps_1: 0x0000808f
[ 5.535227][ T262] mmc1: sdhci: Cmd: 0x00000000 | Max curr: 0x00000000
[ 5.541841][ T262] mmc1: sdhci: Resp[0]: 0x00000000 | Resp[1]: 0x00000000
[ 5.548454][ T262] mmc1: sdhci: Resp[2]: 0x00000000 | Resp[3]: 0x00000000
[ 5.555079][ T262] mmc1: sdhci: Host ctl2: 0x00000000
[ 5.559651][ T262] mmc1: sdhci_msm: ----------- VENDOR REGISTER DUMP-----------
[ 5.566621][ T262] mmc1: sdhci_msm: DLL sts: 0x00000000 | DLL cfg: 0x6000642c | DLL cfg2: 0x0020a000
[ 5.575465][ T262] mmc1: sdhci_msm: DLL cfg3: 0x00000000 | DLL usr ctl: 0x00010800 | DDR cfg: 0x80040873
[ 5.584658][ T262] mmc1: sdhci_msm: Vndr func: 0x00018a9c | Vndr func2 : 0xf88218a8 Vndr func3: 0x02626040
Fixes: 0eb0d9f4de34 ("mmc: sdhci-msm: Initial support for Qualcomm chipsets")
Signed-off-by: Shaik Sajida Bhanu <quic_c_sbhanu@xxxxxxxxxxx>
So this looks good to me, but I can't apply it until I get a patch
that updates the DT doc too.
Okay, so since we are (I have already queued the patches for v5.19)
moving the DT bindings into the yaml format, I decided to queue
$subject patch, as is, for fixes. Moreover, I added a stable tag to
it.
Please send and patch on top of the new yaml based DT bindings to add
the property for the reset.
Thanks and kind regards
Uffe
Kind regards
Uffe
Hi,
Sure Thank you.
Sure will post the YAML based DT bindings for resets changes once base
YAML changes merged.
Thanks,
Sajida
---
Changes since V4:
- Called reset_control_put() in error path.
Changes since V3:
- Used reset controller local variable as suggested by
Bjorn Andersson.
- Passed NULL as a parameter to
devm_reset_control_get_optional_exclusive() as suggested by
Bjorn Andersson.
- Replaced devm_reset_control_get_optional_exclusive() with
reset_control_get_optional_exclusive() and called
reset_control_put() before returning to clear the reset
controller as suggested by Bjorn Andersson.
Changes since V2:
- Dropped new line after fixes tag as suggested by Bjorn
Andersson.
- Passed device structure instead of passing platform_device
structure as a argument for sdhci_msm_gcc_reset() as suggested
by Bjorn Andersson.
- Replaced dev_err() with dev_err_probe() as suggested by Bjorn
Andersson.
Changes since V1:
- Added fixes tag as suggested by Ulf Hansson.
- Replaced devm_reset_control_get() with
devm_reset_control_get_optional_exclusive() as suggested by
Ulf Hansson.
---
drivers/mmc/host/sdhci-msm.c | 42 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 42 insertions(+)
diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index 50c71e0..ff9f5b6 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -17,6 +17,7 @@
#include <linux/regulator/consumer.h>
#include <linux/interconnect.h>
#include <linux/pinctrl/consumer.h>
+#include <linux/reset.h>
#include "sdhci-pltfm.h"
#include "cqhci.h"
@@ -2482,6 +2483,43 @@ static inline void sdhci_msm_get_of_property(struct platform_device *pdev,
of_property_read_u32(node, "qcom,dll-config", &msm_host->dll_config);
}
+static int sdhci_msm_gcc_reset(struct device *dev, struct sdhci_host *host)
+{
+ struct reset_control *reset;
+ int ret = 0;
+
+ reset = reset_control_get_optional_exclusive(dev, NULL);
+ if (IS_ERR(reset))
+ return dev_err_probe(dev, PTR_ERR(reset),
+ "unable to acquire core_reset\n");
+
+ if (!reset)
+ return ret;
+
+ ret = reset_control_assert(reset);
+ if (ret) {
+ reset_control_put(reset);
+ return dev_err_probe(dev, ret, "core_reset assert failed\n");
+ }
+
+ /*
+ * The hardware requirement for delay between assert/deassert
+ * is at least 3-4 sleep clock (32.7KHz) cycles, which comes to
+ * ~125us (4/32768). To be on the safe side add 200us delay.
+ */
+ usleep_range(200, 210);
+
+ ret = reset_control_deassert(reset);
+ if (ret) {
+ reset_control_put(reset);
+ return dev_err_probe(dev, ret, "core_reset deassert failed\n");
+ }
+
+ usleep_range(200, 210);
+ reset_control_put(reset);
+
+ return ret;
+}
static int sdhci_msm_probe(struct platform_device *pdev)
{
@@ -2529,6 +2567,10 @@ static int sdhci_msm_probe(struct platform_device *pdev)
msm_host->saved_tuning_phase = INVALID_TUNING_PHASE;
+ ret = sdhci_msm_gcc_reset(&pdev->dev, host);
+ if (ret)
+ goto pltfm_free;
+
/* Setup SDCC bus voter clock. */
msm_host->bus_clk = devm_clk_get(&pdev->dev, "bus");
if (!IS_ERR(msm_host->bus_clk)) {
--
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