Re: [PATCH v1] mmc: sdhci_am654: Add sdhci_am654_start_signal_voltage_switch
From: Judith Mendez
Date: Wed Sep 11 2024 - 10:34:59 EST
Hi Adrian,
On 9/11/24 12:17 AM, Adrian Hunter wrote:
On 11/09/24 02:22, Judith Mendez wrote:
Hi Adrian,
On 9/10/24 12:10 PM, Adrian Hunter wrote:
On 10/09/24 17:30, Judith Mendez wrote:
Hi Adrian,
On 9/9/24 1:26 AM, Adrian Hunter wrote:
On 6/09/24 20:50, Judith Mendez wrote:
The sdhci_start_signal_voltage_switch function sets
V1P8_SIGNAL_ENA by default after switching to 1v8 signaling.
V1P8_SIGNAL_ENA determines whether to launch cmd/data on neg
edge or pos edge of clock.
Due to some eMMC and SD failures seen across am62x platform,
do not set V1P8_SIGNAL_ENA by default, only enable the bit
for devices that require this bit in order to switch to 1v8
voltage for uhs modes.
Signed-off-by: Judith Mendez <jm@xxxxxx>
---
drivers/mmc/host/sdhci_am654.c | 86 ++++++++++++++++++++++++++++++++++
1 file changed, 86 insertions(+)
diff --git a/drivers/mmc/host/sdhci_am654.c b/drivers/mmc/host/sdhci_am654.c
index 0aa3c40ea6ed8..fb6232e56606b 100644
--- a/drivers/mmc/host/sdhci_am654.c
+++ b/drivers/mmc/host/sdhci_am654.c
@@ -155,6 +155,7 @@ struct sdhci_am654_data {
u32 tuning_loop;
#define SDHCI_AM654_QUIRK_FORCE_CDTEST BIT(0)
+#define SDHCI_AM654_QUIRK_SET_V1P8_ENA BIT(1)
It would be better for the quirk to represent the deviation
from normal i.e.
#define SDHCI_AM654_QUIRK_SUPPRESS_V1P8_ENA BIT(1)
};
struct window {
@@ -356,6 +357,79 @@ static void sdhci_j721e_4bit_set_clock(struct sdhci_host *host,
sdhci_set_clock(host, clock);
}
+int sdhci_am654_start_signal_voltage_switch(struct mmc_host *mmc,
+ struct mmc_ios *ios)
Simpler to call sdhci_start_signal_voltage_switch() for the normal
case e.g.
This is simpler, so sure will use thanks.
static int sdhci_am654_start_signal_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios)
{
struct sdhci_host *host = mmc_priv(mmc);
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
if ((sdhci_am654->quirks & SDHCI_AM654_QUIRK_SUPPRESS_V1P8_ENA) &&
ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180) {
ret = mmc_regulator_set_vqmmc(mmc, ios);
if (ret < 0) {
pr_warn("%s: Switching to 1.8V signalling voltage failed\n",
mmc_hostname(mmc));
return -EIO;
}
return 0;
}
return sdhci_start_signal_voltage_switch(mmc, ios);
}
+{
+ struct sdhci_host *host = mmc_priv(mmc);
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
+ u16 ctrl;
+ int ret;
+
+ if (host->version < SDHCI_SPEC_300)
+ return 0;
+
+ switch (ios->signal_voltage) {
+ case MMC_SIGNAL_VOLTAGE_330:
+ if (!(host->flags & SDHCI_SIGNALING_330))
+ return -EINVAL;
+
+ ctrl &= ~SDHCI_CTRL_VDD_180;
+ sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
+
+ if (!IS_ERR(mmc->supply.vqmmc)) {
+ ret = mmc_regulator_set_vqmmc(mmc, ios);
+ if (ret < 0) {
+ pr_warn("%s: Switching to 3.3V signalling voltage failed\n",
+ mmc_hostname(mmc));
+ return -EIO;
+ }
+ }
+
+ usleep_range(5000, 5500);
+
+ ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+ if (!(ctrl & SDHCI_CTRL_VDD_180))
+ return 0;
+
+ pr_warn("%s: 3.3V regulator output did not become stable\n",
+ mmc_hostname(mmc));
+
+ return -EAGAIN;
+
+ case MMC_SIGNAL_VOLTAGE_180:
+ if (!(host->flags & SDHCI_SIGNALING_180))
+ return -EINVAL;
+
+ if (!IS_ERR(mmc->supply.vqmmc)) {
+ ret = mmc_regulator_set_vqmmc(mmc, ios);
+ if (ret < 0) {
+ pr_warn("%s: Switching to 1.8V signalling voltage failed\n",
+ mmc_hostname(mmc));
+ return -EIO;
+ }
+ }
+
+ if (sdhci_am654->quirks & SDHCI_AM654_QUIRK_SET_V1P8_ENA) {
+ ctrl |= SDHCI_CTRL_VDD_180;
+ sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
+
+ ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+ if (ctrl & SDHCI_CTRL_VDD_180)
+ return 0;
+
+ pr_warn("%s: 1.8V regulator output did not become stable\n",
+ mmc_hostname(mmc));
+
+ return -EAGAIN;
+ }
+ return 0;
+
+ default:
+ return 0;
+ }
+}
+
static u8 sdhci_am654_write_power_on(struct sdhci_host *host, u8 val, int reg)
{
writeb(val, host->ioaddr + reg);
@@ -801,6 +875,8 @@ static int sdhci_am654_get_of_property(struct platform_device *pdev,
struct sdhci_am654_data *sdhci_am654)
{
struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct device_node *node;
int drv_strength;
int ret;
@@ -844,6 +920,15 @@ static int sdhci_am654_get_of_property(struct platform_device *pdev,
if (device_property_read_bool(dev, "ti,fails-without-test-cd"))
sdhci_am654->quirks |= SDHCI_AM654_QUIRK_FORCE_CDTEST;
+ node = of_parse_phandle(np, "vmmc-supply", 0);
+
+ if (node) {
+ node = of_parse_phandle(np, "vqmmc-supply", 0);
+
+ if (!node)
+ sdhci_am654->quirks |= SDHCI_AM654_QUIRK_SET_V1P8_ENA;
+ }
It would be simpler without 'np' and 'node'. Not sure
what the rule is meant to be, but it could be something like:
if (of_parse_phandle(dev->of_node, "vmmc-supply", 0) &&
of_parse_phandle(dev->of_node, "vqmmc-supply", 0)
sdhci_am654->quirks |= SDHCI_AM654_QUIRK_SUPPRESS_V1P8_ENA;
My issue with this is that I also need the quirk (SDHCI_AM654_QUIRK_SUPPRESS_V1P8_ENA) for eMMC. DT node for eMMC does
not include vmmc and vqmmc supplies. That is why I had the quirk logic
inverted.
Ideally there would be a more direct way to distinguish eMMC, but
otherwise, having both supplies or neither would be:
if (!!of_parse_phandle(dev->of_node, "vmmc-supply", 0) ==
!!of_parse_phandle(dev->of_node, "vqmmc-supply", 0))
sdhci_am654->quirks |= SDHCI_AM654_QUIRK_SUPPRESS_V1P8_ENA;
Not sure I love the double NOT, but ok, I can use this, will fix for v2.
It could use a comment, including about the eMMC thing.
Sure, will add. Thanks.
Thanks for your suggestion!
~ Judith
This patch fixes timing issues with both eMMC and SD. (:
~ Judith
+
sdhci_get_of_property(pdev);
return 0;
@@ -940,6 +1025,7 @@ static int sdhci_am654_probe(struct platform_device *pdev)
goto err_pltfm_free;
}
+ host->mmc_host_ops.start_signal_voltage_switch = sdhci_am654_start_signal_voltage_switch;
host->mmc_host_ops.execute_tuning = sdhci_am654_execute_tuning;
pm_runtime_get_noresume(dev);
base-commit: cf6444ba528f043398b112ac36e041a4d8685cb1