[RFC 2/3] mmc: sdhci: add host_ops->voltage_switch callback for all other voltages
From: Jisheng Zhang <hidden>
Date: 2015-09-02 07:08:41
Also in:
linux-mmc, lkml
On Wed, 2 Sep 2015 01:02:17 +0530 Vaibhav Hiremath [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Currently, the sdhci_do_start_signal_voltage_switch() function invokes controller specific voltage switch configuration only for 1.8v usecase; but it is required for others as well. For example, in case of PXA1928 SDH controller, we need to set different configuration for 3.3, 1.8 and 1.2 volt support (I/O domain power control register). Signed-off-by: Vaibhav Hiremath <redacted> --- Note: Currently ->voltage_switch() callback is only supported in f_sdh30 driver. And I am not sure on the dependency of execution sequence for that device. I could have moved ->voltage_switch() call at one common place (above/below), but was not quite sure about it. So, replicated/duplicated the call for other voltages. drivers/mmc/host/sdhci.c | 8 ++++++++ 1 file changed, 8 insertions(+)diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 3dd295f..b59b76d 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c@@ -1753,6 +1753,10 @@ static int sdhci_do_start_signal_voltage_switch(struct sdhci_host *host, /* Wait for 5ms */ usleep_range(5000, 5500); + /* Some controller need to do more when switching */ + if (host->ops->voltage_switch) + host->ops->voltage_switch(host, MMC_SIGNAL_VOLTAGE_330);
Could this be implemented by regulator API? From patch set 3/3, the pxa1928 voltage_switch hook is to operate the IO pad registers, this seems not belong to the SDHC IP core. Thanks, Jisheng
quoted hunk ↗ jump to hunk
+ /* 3.3V regulator output should be stable within 5 ms */ ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2); if (!(ctrl & SDHCI_CTRL_VDD_180))@@ -1803,6 +1807,10 @@ static int sdhci_do_start_signal_voltage_switch(struct sdhci_host *host, return -EIO; } } + /* Some controller need to do more when switching */ + if (host->ops->voltage_switch) + host->ops->voltage_switch(host, MMC_SIGNAL_VOLTAGE_120); + return 0; default: /* No signal voltage switch required */