Hi Michal,
Thanks again for the feedback. I replied inline
>-----Original Message-----
>From: Michal Simek <michal.simek@xxxxxxxxxx>
>Sent: Wednesday, October 7, 2020 4:34 PM
>To: Zulkifli, Muhammad Husaini <muhammad.husaini.zulkifli@xxxxxxxxx>;
>Hunter, Adrian <adrian.hunter@xxxxxxxxx>; michal.simek@xxxxxxxxxx;
>sudeep.holla@xxxxxxx; ulf.hansson@xxxxxxxxxx; linux-mmc@xxxxxxxxxxxxxxx;
>linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
>Cc: Raja Subramanian, Lakshmi Bai <lakshmi.bai.raja.subramanian@xxxxxxxxx>;
>Wan Mohamad, Wan Ahmad Zainie
><wan.ahmad.zainie.wan.mohamad@xxxxxxxxx>; arnd@xxxxxxxx
>Subject: Re: [PATCH v3 1/2] mmc: sdhci-of-arasan: Enable UHS-1 support for
>Keem Bay SOC
>
>
>
>On 06. 10. 20 17:55, muhammad.husaini.zulkifli@xxxxxxxxx wrote:
>> From: Muhammad Husaini Zulkifli <muhammad.husaini.zulkifli@xxxxxxxxx>
>>
>> Voltage switching sequence is needed to support UHS-1 interface.
>> There are 2 places to control the voltage.
>> 1) By setting the AON register using firmware driver calling
>> system-level platform management layer (SMC) to set the register.
>> 2) By controlling the GPIO expander value to drive either 1.8V or 3.3V
>> for power mux input.
>>
>> Signed-off-by: Muhammad Husaini Zulkifli
>> <muhammad.husaini.zulkifli@xxxxxxxxx>
>> Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxx>
>> Reviewed-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
>> ---
>> drivers/mmc/host/sdhci-of-arasan.c | 127
>> +++++++++++++++++++++++++++++
>> 1 file changed, 127 insertions(+)
>>
>> diff --git a/drivers/mmc/host/sdhci-of-arasan.c
>> b/drivers/mmc/host/sdhci-of-arasan.c
>> index f186fbd016b1..e681e6f860ba 100644
>> --- a/drivers/mmc/host/sdhci-of-arasan.c
>> +++ b/drivers/mmc/host/sdhci-of-arasan.c
>> @@ -16,6 +16,7 @@
>> */
>>
>> #include <linux/clk-provider.h>
>> +#include <linux/gpio/consumer.h>
>> #include <linux/mfd/syscon.h>
>> #include <linux/module.h>
>> #include <linux/of_device.h>
>> @@ -23,6 +24,7 @@
>> #include <linux/regmap.h>
>> #include <linux/of.h>
>> #include <linux/firmware/xlnx-zynqmp.h>
>> +#include <linux/firmware/intel/keembay_firmware.h>
>>
>> #include "cqhci.h"
>> #include "sdhci-pltfm.h"
>> @@ -150,6 +152,7 @@ struct sdhci_arasan_data {
>> struct regmap *soc_ctl_base;
>> const struct sdhci_arasan_soc_ctl_map *soc_ctl_map;
>> unsigned int quirks;
>> + struct gpio_desc *uhs_gpio;
>>
>> /* Controller does not have CD wired and will not function normally without
>*/
>> #define SDHCI_ARASAN_QUIRK_FORCE_CDTEST BIT(0)
>> @@ -361,6 +364,113 @@ static int sdhci_arasan_voltage_switch(struct
>mmc_host *mmc,
>> return -EINVAL;
>> }
>>
>> +static int sdhci_arasan_keembay_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_arasan_data *sdhci_arasan =
>sdhci_pltfm_priv(pltfm_host);
>> + u16 ctrl_2;
>> + u16 clk;
>
>nit: put it to one line.
Noted. Done the changes.
>
>> + int ret;
>> +
>> + switch (ios->signal_voltage) {
>> + case MMC_SIGNAL_VOLTAGE_180:
>> + clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
>
>nit: double space
Noted. Done the changes.
>
>> + clk &= ~SDHCI_CLOCK_CARD_EN;
>> + sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
>> +
>> + clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
>
>nit: double space again.
Noted. Done the changes.
>
>> + if (clk & SDHCI_CLOCK_CARD_EN)
>> + return -EAGAIN;
>> +
>> + sdhci_writeb(host, SDHCI_POWER_ON | SDHCI_POWER_180,
>> + SDHCI_POWER_CONTROL);
>> +
>> + /*
>> + * Set VDDIO_B voltage to Low for 1.8V
>> + * which is controlling by GPIO Expander.
>> + */
>> + gpiod_set_value_cansleep(sdhci_arasan->uhs_gpio, 0);
>> +
>> + /*
>> + * This is like final gatekeeper. Need to ensure changed voltage
>> + * is settled before and after turn on this bit.
>> + */
>> + usleep_range(1000, 1100);
>> +
>> + ret =
>keembay_sd_voltage_selection(KEEMBAY_SET_1V8_VOLT);
>> + if (ret)
>> + return ret;
>> +
>> + usleep_range(1000, 1100);
>> +
>> + ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>> + ctrl_2 |= SDHCI_CTRL_VDD_180;
>> + sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
>> +
>> + /* Sleep for 5ms to stabilize 1.8V regulator */
>> + usleep_range(5000, 5500);
>> +
>> + /* 1.8V regulator output should be stable within 5 ms */
>> + ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>> + if (!(ctrl_2 & SDHCI_CTRL_VDD_180))
>> + return -EAGAIN;
>> +
>> + clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
>> + clk |= SDHCI_CLOCK_CARD_EN;
>> + sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
>> + break;
>> + case MMC_SIGNAL_VOLTAGE_330:
>> + /*
>> + * Set VDDIO_B voltage to High for 3.3V
>> + * which is controlling by GPIO Expander.
>> + */
>> + gpiod_set_value_cansleep(sdhci_arasan->uhs_gpio, 1);
>> +
>> + /*
>> + * This is like final gatekeeper. Need to ensure changed voltage
>> + * is settled before and after turn on this bit.
>> + */
>> + usleep_range(1000, 1100);
>> +
>> + ret =
>keembay_sd_voltage_selection(KEEMBAY_SET_3V3_VOLT);
>> + if (ret)
>> + return ret;
>> +
>> + usleep_range(1000, 1100);
>> +
>> + /* Set 1.8V Signal Enable in the Host Control2 register to 0 */
>> + ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>> + ctrl_2 &= ~SDHCI_CTRL_VDD_180;
>> + sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
>> +
>> + /* Sleep for 5ms to stabilize 3.3V regulator */
>> + usleep_range(5000, 5500);
>> +
>> + /* 3.3V regulator output should be stable within 5 ms */
>> + ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>> + if (ctrl_2 & SDHCI_CTRL_VDD_180)
>> + return -EAGAIN;
>> +
>> + break;
>> + default:
>> + return -EINVAL;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int sdhci_arasan_keembay_select_drive_strength(struct mmc_card
>*card,
>> + unsigned int max_dtr, int host_drv,
>> + int card_drv, int *drv_type)
>> +{
>> + if (card->host->ios.signal_voltage == MMC_SIGNAL_VOLTAGE_180)
>> + *drv_type = MMC_SET_DRIVER_TYPE_C;
>> +
>> + return 0;
>> +}
>> +
>> static const struct sdhci_ops sdhci_arasan_ops = {
>> .set_clock = sdhci_arasan_set_clock,
>> .get_max_clock = sdhci_pltfm_clk_get_max_clock, @@ -1521,6 +1631,7
>> @@ static int sdhci_arasan_probe(struct platform_device *pdev)
>> struct sdhci_pltfm_host *pltfm_host;
>> struct sdhci_arasan_data *sdhci_arasan;
>> struct device_node *np = pdev->dev.of_node;
>> + struct device *dev = &pdev->dev;
>
>nit: I got this but as I see 3 lines below maybe would be better to use it
>everywhere but it can be done in separate patch.
>
>> const struct sdhci_arasan_of_data *data;
>>
>> match = of_match_node(sdhci_arasan_of_match, pdev->dev.of_node);
>@@
>> -1600,6 +1711,22 @@ static int sdhci_arasan_probe(struct platform_device
>*pdev)
>> host->mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
>> }
>>
>> + if (of_device_is_compatible(np, "intel,keembay-sdhci-5.1-sd")) {
>> + struct gpio_desc *uhs;
>> +
>> + uhs = devm_gpiod_get_optional(dev, "uhs",
>GPIOD_OUT_HIGH);
>
>I can't see change in dt binding to record uhs gpio.
Noted. Done the changes. Will add binding for this
>
>
>Better
>sdhci_arasan->uhs_gpio = devm_gpiod_get_optional(dev, "uhs",
>GPIOD_OUT_HIGH);
>
>then you can avoid uhs variable.
Will remain as it is to make it more readable.
>
>> + if (IS_ERR(uhs))
>> + return dev_err_probe(dev, PTR_ERR(uhs), "can't get
>uhs gpio\n");
>> +
>> + sdhci_arasan->uhs_gpio = uhs;
>> +
>> + host->mmc_host_ops.start_signal_voltage_switch =
>> + sdhci_arasan_keembay_voltage_switch;
>> +
>> + host->mmc_host_ops.select_drive_strength =
>> + sdhci_arasan_keembay_select_drive_strength;
>> + }
>> +
>> sdhci_arasan_update_baseclkfreq(host);
>>
>> ret = sdhci_arasan_register_sdclk(sdhci_arasan, clk_xin,
>> &pdev->dev);
>>
>
>Thanks,
>Michal
