Hi,
On Sun, Feb 11, 2018 at 10:01 PM, Vijay Viswanath
<vviswana@xxxxxxxxxxxxxx> wrote:
> During probe check whether the vdd-io regulator of sdhc platform device
> can support 1.8V and 3V and store this information as a capability of
> platform device.
>
> Signed-off-by: Vijay Viswanath <vviswana@xxxxxxxxxxxxxx>
> ---
> drivers/mmc/host/sdhci-msm.c | 38 ++++++++++++++++++++++++++++++++++++++
> 1 file changed, 38 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index c283291..5c23e92 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -23,6 +23,7 @@
> #include <linux/iopoll.h>
>
> #include "sdhci-pltfm.h"
> +#include <linux/regulator/consumer.h>
This is a strange sort order for this include file. Why is it after
the local include?
> #define CORE_MCI_VERSION 0x50
> #define CORE_VERSION_MAJOR_SHIFT 28
> @@ -81,6 +82,9 @@
> #define CORE_HC_SELECT_IN_HS400 (6 << 19)
> #define CORE_HC_SELECT_IN_MASK (7 << 19)
>
> +#define CORE_3_0V_SUPPORT (1 << 25)
> +#define CORE_1_8V_SUPPORT (1 << 26)
> +
Is there something magical about 25 and 26? This is a new caps field,
so I'd have expected 0 and 1.
> #define CORE_CSR_CDC_CTLR_CFG0 0x130
> #define CORE_SW_TRIG_FULL_CALIB BIT(16)
> #define CORE_HW_AUTOCAL_ENA BIT(17)
> @@ -148,6 +152,7 @@ struct sdhci_msm_host {
> u32 curr_io_level;
> wait_queue_head_t pwr_irq_wait;
> bool pwr_irq_flag;
> + u32 caps_0;
> };
>
> static unsigned int msm_get_clock_rate_for_bus_mode(struct sdhci_host *host,
> @@ -1313,6 +1318,35 @@ static void sdhci_msm_writeb(struct sdhci_host *host, u8 val, int reg)
> sdhci_msm_check_power_status(host, req_type);
> }
>
> +static int sdhci_msm_set_regulator_caps(struct sdhci_msm_host *msm_host)
> +{
> + struct mmc_host *mmc = msm_host->mmc;
> + struct regulator *supply = mmc->supply.vqmmc;
> + int i, count;
> + u32 caps = 0, vdd_uV;
> +
> + if (!IS_ERR(mmc->supply.vqmmc)) {
> + count = regulator_count_voltages(supply);
> + if (count < 0)
> + return count;
> + for (i = 0; i < count; i++) {
> + vdd_uV = regulator_list_voltage(supply, i);
> + if (vdd_uV <= 0)
> + continue;
> + if (vdd_uV > 2700000)
> + caps |= CORE_3_0V_SUPPORT;
> + if (vdd_uV < 1950000)
> + caps |= CORE_1_8V_SUPPORT;
> + }
Shouldn't you be using regulator_is_supported_voltage() rather than
open coding? Also: I've never personally worked on a device where it
was used, but there is definitely a concept floating about of a
voltage level of 1.2V. Maybe should copy the ranges from
mmc_regulator_set_vqmmc()?
Also: seems like you should have some way to deal with "caps" ending
up w/ no bits set. IIRC you can have a regulator that can be enabled
/ disabled but doesn't list a voltage, so if someone messed up their
device tree you could end up in this case. Should you print a
warning? ...or treat it as if we support "3.0V"? ...or ? I guess it
depends on how do you want patch #2 to behave in that case.
> + }
How should things behave if vqmmc is an error? In that case is it
important to not set "CORE_IO_PAD_PWR_SWITCH_EN" in patch set #2?
...or should you set "CORE_IO_PAD_PWR_SWITCH_EN" but then make sure
you don't set "CORE_IO_PAD_PWR_SWITCH"?
> + msm_host->caps_0 |= caps;
> + pr_debug("%s: %s: supported caps: 0x%08x\n", mmc_hostname(mmc),
> + __func__, caps);
> +
> + return 0;
> +}
> +
> +
> static const struct of_device_id sdhci_msm_dt_match[] = {
> { .compatible = "qcom,sdhci-msm-v4" },
> {},
> @@ -1530,6 +1564,10 @@ static int sdhci_msm_probe(struct platform_device *pdev)
> ret = sdhci_add_host(host);
> if (ret)
> goto pm_runtime_disable;
> + ret = sdhci_msm_set_regulator_caps(msm_host);
> + if (ret)
> + dev_err(&pdev->dev, "%s: Failed to set regulator caps: %d\n",
> + __func__, ret);
Why do you need __func__ here? You're already using dev_err(), that
gives an idea of where we are.
>
> pm_runtime_mark_last_busy(&pdev->dev);
> pm_runtime_put_autosuspend(&pdev->dev);
> --
> Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc.
> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.
>
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