kernel.git/drivers/mmc/core/sd.c, branch linux-3.11.y

mmc: core: Add shutdown callback for SD bus_ops

2013-06-27T16:39:19Z

For the SD .shutdown callback we re-use the SD suspend function since it performs the relevant actions. Signed-off-by: Ulf Hansson Signed-off-by: Chris Ball

mmc: core: Push common suspend|resume code into each bus_ops

2013-06-27T16:39:16Z

By moving code from the mmc_suspend|resume_host down into each .suspend|resume bus_ops callback, we get a more flexible solution. Some nice side effects are that we get a better understanding of each bus_ops suspend|resume sequence and the common code don't have to take care of specific corner cases, especially for the SDIO case. Signed-off-by: Ulf Hansson Tested-by: Jaehoon Chung Signed-off-by: Chris Ball

mmc: core: Support aggressive power management for (e)MMC/SD

2013-05-26T18:23:17Z

Aggressive power management is suitable when saving power is essential. At request inactivity timeout, aka pm runtime autosuspend timeout, the card will be suspended. Once a new request arrives, the card will be re-initalized and thus the first request will suffer from a latency. This latency is card-specific, experiments has shown in general that SD-cards has quite poor initialization time, around 300ms-1100ms. eMMC is not surprisingly far better but still a couple of hundreds of ms has been observed. Except for the request latency, it is important to know that suspending the card will also prevent the card from executing internal house-keeping operations in idle mode. This could mean degradation in performance. To use this feature make sure the request inactivity timeout is chosen carefully. This has not been done as a part of this patch. Enable this feature by using host cap MMC_CAP_AGGRESSIVE_PM and by setting CONFIG_MMC_UNSAFE_RESUME. Signed-off-by: Ulf Hansson Signed-off-by: Chris Ball

mmc: block: Enable runtime pm for mmc blkdevice

2013-05-26T18:23:16Z

Once the mmc blkdevice is being probed, runtime pm will be enabled. By using runtime autosuspend, the power save operations can be done when request inactivity occurs for a certain time. Right now the selected timeout value is set to 3 s. Obviously this value will likely need to be configurable somehow since it needs to be trimmed depending on the power save algorithm. For SD-combo cards, we are still leaving the enablement of runtime PM to the SDIO init sequence since it depends on the capabilities of the SDIO func driver. Moreover, when the blk device is being suspended, we make sure the device will be runtime resumed. The reason for doing this is that we want the host suspend sequence to be unaware of any runtime power save operations done for the card in this phase. Thus it can just handle the suspend as the card is fully powered from a runtime perspective. Finally, this patch prepares to make it possible to move BKOPS handling into the runtime callbacks for the mmc bus_ops. Thus IDLE BKOPS can be accomplished. Signed-off-by: Ulf Hansson Signed-off-by: Chris Ball

mmc: core: Only execute tuning for SDR50 and SDR104

2013-05-26T18:23:11Z

Only execute tuning for sd and sdio devices that are using SDR50 or SDR104. Make sure clock is hold during tuning for sdio devices. Signed-off-by: Fredrik Soderstedt Acked-by: Johan Rudholm Acked-by: Ulf Hansson Signed-off-by: Chris Ball

mmc: sdhci: enhance preset value function

2013-02-24T19:37:11Z

4d55c5a1 ("mmc: sdhci: enable preset value after uhs initialization") added preset value support and enabled it by default during sd card init. Below are the enhancements introduced by this patch: 1. In current code, preset value is enabled after setting clock finished, which means the clock is manually set by driver firstly and then suddenly switched to preset value at this point. So the first setting is useless and unnecessary. What's more, the first clock setting may differ from the preset one. The better way is enable preset value just after switch to UHS mode so the preset value can take effect immediately. So move preset value enable from mmc_sd_init_card to sdhci_set_ios which will be called during set timing. 2. In current code, preset value is disabled at the beginning of mmc_attach_sd. It's too late since low freq (400khz) should be set in mmc_power_up. So move preset value disable to sdhci_set_ios which will be called during power up. 3. host->clock and ios->drv_type should also be updated according to the preset value if it's enabled. Current code missed this. 4. This patch also introduce a quirk to disable preset value in case preset value doesn't work. This patch has been verified on sdhci-pxav3 platform with both preset enabled and disabled. Signed-off-by: Kevin Liu Reviewed-by: Ulf Hansson Signed-off-by: Chris Ball

mmc: core: Fixup signal voltage switch

2013-02-24T19:37:08Z

When switching SD and SDIO cards from 3.3V to 1.8V signal levels, the clock should be gated for 5 ms during the step. After enabling the clock, the host should wait for at least 1 ms before checking for failure. Failure by the card to switch is indicated by dat[0:3] being pulled low. The host should check for this condition and power-cycle the card if failure is indicated. Add a retry mechanism for the SDIO case. If the voltage switch fails repeatedly, give up and continue the initialization using the original voltage. This patch places a couple of requirements on the host driver: 1) mmc_set_ios with ios.clock = 0 must gate the clock 2) mmc_power_off must actually cut the power to the card 3) The card_busy host_ops member must be implemented if these requirements are not fulfilled, the 1.8V signal voltage switch will still be attempted but may not be successful. Signed-off-by: Johan Rudholm Signed-off-by: Kevin Liu Acked-by: Ulf Hansson Tested-by: Wei WANG Signed-off-by: Chris Ball

mmc: core: Break out start_signal_voltage_switch

2013-02-24T19:37:07Z

Allow callers to access the start_signal_voltage_switch host_ops member without going through any cmd11 logic. This is mostly a preparation for the following signal voltage switch patch. Also, reset ios.signal_voltage to its original value if start_signal_voltage_switch fails. Signed-off-by: Johan Rudholm Acked-by: Ulf Hansson Tested-by: Wei WANG Signed-off-by: Chris Ball

mmc: sd: Simplify by using mmc_host_uhs

2013-02-24T19:37:05Z

Signed-off-by: Johan Rudholm Acked-by: Ulf Hansson Signed-off-by: Chris Ball

mmc: core: reset signal voltage on power up

2012-07-22T19:25:53Z

Add a call to mmc_set_signal_voltage() to set signal voltage to 3.3v in mmc_power_up so that we do not need to touch signal voltage setting in mmc/sd/sdio init functions and rescan function. For mmc/sd cards, when doing a suspend/resume cycle, consider the unsafe resume case, the card will lose its power and when powered on again, we will set signal voltage to 3.3v in mmc_power_up before its resume function gets called, which will re-init the card. And for sdio cards, when doing a suspend/resume cycle, consider the unsafe resume case, the card will either lose its power or not depending on if it wants to wakeup the host. If power is not maintained, it is the same case as mmc/sd cards. If power is maintained, mmc_power_up will not be called and the card's signal voltage will remain at the last setting. Signed-off-by: Aaron Lu Tested-by: Venkatraman S Signed-off-by: Chris Ball