| Message ID | 1490032253-6030-8-git-send-email-adrian.hunter@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Adrian, On Mon, Mar 20, 2017 at 07:50:35PM +0200, Adrian Hunter wrote: > Make use of an Intel ACPI _DSM that provides eMMC driver strength. > > Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> This is an interesting patch for me because it seems I have to deal with drive-strength soon, as well, for the SDHI driver. You basically fall back here to simply read the drive strength value from ACPI, right? So, do you think it makes sense then to have a similar encoded value from DT (maybe "mmc-fixed-driver-type-<n>" with n=0..4)? This is a largely reduced encoding of what you proposed in 2015 [1] but may be more pragmatic for soldered on-board devices working on their max speeds with fixed voltages and frequencies? Or did I get something wrong? Thanks, Wolfram [1] https://lkml.org/lkml/2015/2/16/273
On 04/04/17 11:48, Wolfram Sang wrote: > Hi Adrian, > > On Mon, Mar 20, 2017 at 07:50:35PM +0200, Adrian Hunter wrote: >> Make use of an Intel ACPI _DSM that provides eMMC driver strength. >> >> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> > > This is an interesting patch for me because it seems I have to deal with > drive-strength soon, as well, for the SDHI driver. You basically fall > back here to simply read the drive strength value from ACPI, right? Yes, it is a single value. I did not design the _DSM, it was a preexisting method. > So, > do you think it makes sense then to have a similar encoded value from DT > (maybe "mmc-fixed-driver-type-<n>" with n=0..4)? The _DSM, being a device-specific method does not have to support different devices with different requirements whereas DT does. > This is a largely > reduced encoding of what you proposed in 2015 [1] but may be more > pragmatic for soldered on-board devices working on their max speeds with > fixed voltages and frequencies? Or did I get something wrong? What I proposed was being forced on me by the requirement to provide a solution that could meet any conceivable need. That gets over-complicated. But as you say, in practice people are probably only interested in providing one value for the max speed / frequency. > > Thanks, > > Wolfram > > [1] https://lkml.org/lkml/2015/2/16/273 > > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> > do you think it makes sense then to have a similar encoded value from DT > > (maybe "mmc-fixed-driver-type-<n>" with n=0..4)? > > The _DSM, being a device-specific method does not have to support different > devices with different requirements whereas DT does. So, it is more like a vendor specific property (e.g. "renesas, mmc-driver-type")? Sorry, I don't know much about ACPI. > > This is a largely > > reduced encoding of what you proposed in 2015 [1] but may be more > > pragmatic for soldered on-board devices working on their max speeds with > > fixed voltages and frequencies? Or did I get something wrong? > > What I proposed was being forced on me by the requirement to provide a > solution that could meet any conceivable need. That gets over-complicated. Yeah, that became pretty clear. > But as you say, in practice people are probably only interested in providing > one value for the max speed / frequency. OK. Thanks for your answers! Much appreciated.
On 19/04/17 15:24, Wolfram Sang wrote: > >>> do you think it makes sense then to have a similar encoded value from DT >>> (maybe "mmc-fixed-driver-type-<n>" with n=0..4)? >> >> The _DSM, being a device-specific method does not have to support different >> devices with different requirements whereas DT does. > > So, it is more like a vendor specific property (e.g. "renesas, > mmc-driver-type")? Sorry, I don't know much about ACPI. Yes, it is effectively vendor-specific in this case. -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c index 3564327c9c7b..351920f4ec42 100644 --- a/drivers/mmc/host/sdhci-pci-core.c +++ b/drivers/mmc/host/sdhci-pci-core.c @@ -261,11 +261,13 @@ static int mfd_sdio_probe_slot(struct sdhci_pci_slot *slot) enum { INTEL_DSM_FNS = 0, + INTEL_DSM_DRV_STRENGTH = 9, INTEL_DSM_D3_RETUNE = 10, }; struct intel_host { u32 dsm_fns; + int drv_strength; bool d3_retune; }; @@ -326,6 +328,9 @@ static void intel_dsm_init(struct intel_host *intel_host, struct device *dev, pr_debug("%s: DSM function mask %#x\n", mmc_hostname(mmc), intel_host->dsm_fns); + err = intel_dsm(intel_host, dev, INTEL_DSM_DRV_STRENGTH, &val); + intel_host->drv_strength = err ? 0 : val; + err = intel_dsm(intel_host, dev, INTEL_DSM_D3_RETUNE, &val); intel_host->d3_retune = err ? true : !!val; } @@ -345,67 +350,15 @@ static void sdhci_pci_int_hw_reset(struct sdhci_host *host) usleep_range(300, 1000); } -static int spt_select_drive_strength(struct sdhci_host *host, - struct mmc_card *card, - unsigned int max_dtr, - int host_drv, int card_drv, int *drv_type) +static int intel_select_drive_strength(struct mmc_card *card, + unsigned int max_dtr, int host_drv, + int card_drv, int *drv_type) { - int drive_strength; - - if (sdhci_pci_spt_drive_strength > 0) - drive_strength = sdhci_pci_spt_drive_strength & 0xf; - else - drive_strength = 0; /* Default 50-ohm */ - - if ((mmc_driver_type_mask(drive_strength) & card_drv) == 0) - drive_strength = 0; /* Default 50-ohm */ - - return drive_strength; -} - -/* Try to read the drive strength from the card */ -static void spt_read_drive_strength(struct sdhci_host *host) -{ - u32 val, i, t; - u16 m; - - if (sdhci_pci_spt_drive_strength) - return; - - sdhci_pci_spt_drive_strength = -1; - - m = sdhci_readw(host, SDHCI_HOST_CONTROL2) & 0x7; - if (m != 3 && m != 5) - return; - val = sdhci_readl(host, SDHCI_PRESENT_STATE); - if (val & 0x3) - return; - sdhci_writel(host, 0x007f0023, SDHCI_INT_ENABLE); - sdhci_writel(host, 0, SDHCI_SIGNAL_ENABLE); - sdhci_writew(host, 0x10, SDHCI_TRANSFER_MODE); - sdhci_writeb(host, 0xe, SDHCI_TIMEOUT_CONTROL); - sdhci_writew(host, 512, SDHCI_BLOCK_SIZE); - sdhci_writew(host, 1, SDHCI_BLOCK_COUNT); - sdhci_writel(host, 0, SDHCI_ARGUMENT); - sdhci_writew(host, 0x83b, SDHCI_COMMAND); - for (i = 0; i < 1000; i++) { - val = sdhci_readl(host, SDHCI_INT_STATUS); - if (val & 0xffff8000) - return; - if (val & 0x20) - break; - udelay(1); - } - val = sdhci_readl(host, SDHCI_PRESENT_STATE); - if (!(val & 0x800)) - return; - for (i = 0; i < 47; i++) - val = sdhci_readl(host, SDHCI_BUFFER); - t = val & 0xf00; - if (t != 0x200 && t != 0x300) - return; + struct sdhci_host *host = mmc_priv(card->host); + struct sdhci_pci_slot *slot = sdhci_priv(host); + struct intel_host *intel_host = sdhci_pci_priv(slot); - sdhci_pci_spt_drive_strength = 0x10 | ((val >> 12) & 0xf); + return intel_host->drv_strength; } static int bxt_get_cd(struct mmc_host *mmc) @@ -451,10 +404,8 @@ static int byt_emmc_probe_slot(struct sdhci_pci_slot *slot) slot->hw_reset = sdhci_pci_int_hw_reset; if (slot->chip->pdev->device == PCI_DEVICE_ID_INTEL_BSW_EMMC) slot->host->timeout_clk = 1000; /* 1000 kHz i.e. 1 MHz */ - if (slot->chip->pdev->device == PCI_DEVICE_ID_INTEL_SPT_EMMC) { - spt_read_drive_strength(slot->host); - slot->select_drive_strength = spt_select_drive_strength; - } + slot->host->mmc_host_ops.select_drive_strength = + intel_select_drive_strength; return 0; } diff --git a/drivers/mmc/host/sdhci-pci-data.c b/drivers/mmc/host/sdhci-pci-data.c index 56fddc622a54..a611217769f5 100644 --- a/drivers/mmc/host/sdhci-pci-data.c +++ b/drivers/mmc/host/sdhci-pci-data.c @@ -3,6 +3,3 @@ struct sdhci_pci_data *(*sdhci_pci_get_data)(struct pci_dev *pdev, int slotno); EXPORT_SYMBOL_GPL(sdhci_pci_get_data); - -int sdhci_pci_spt_drive_strength; -EXPORT_SYMBOL_GPL(sdhci_pci_spt_drive_strength);
Make use of an Intel ACPI _DSM that provides eMMC driver strength. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> --- drivers/mmc/host/sdhci-pci-core.c | 77 +++++++-------------------------------- drivers/mmc/host/sdhci-pci-data.c | 3 -- 2 files changed, 14 insertions(+), 66 deletions(-)