mmc: mmci: Add callbacks for to manage signal voltage switch

A variant may need to define some actions before and after a voltage
switch.

This patch adds 2 callbacks to manage signal voltage switch in the struct
mmci_host_ops. ->pre_sig_volt_switch() allows to prepare a signal voltage
switch before sending the SD_SWITCH_VOLTAGE command (CMD11).
->post_sig_volt_switch callback allows specific actions to be executed,
after the I/O signal voltage level has been changed.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Link: https://lore.kernel.org/r/20200128090636.13689-8-ludovic.barre@st.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index d0a041c..24e6301 100644 (file)
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -22,6 +22,7 @@
 #include <linux/mmc/pm.h>
 #include <linux/mmc/host.h>
 #include <linux/mmc/card.h>
+#include <linux/mmc/sd.h>
 #include <linux/mmc/slot-gpio.h>
 #include <linux/amba/bus.h>
 #include <linux/clk.h>
@@ -1217,6 +1218,9 @@ mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c)
                writel_relaxed(clks, host->base + MMCIDATATIMER);
        }
 
+       if (host->ops->pre_sig_volt_switch && cmd->opcode == SD_SWITCH_VOLTAGE)
+               host->ops->pre_sig_volt_switch(host);
+
        if (/*interrupt*/0)
                c |= MCI_CPSM_INTERRUPT;
 
@@ -1830,6 +1834,7 @@ static int mmci_get_cd(struct mmc_host *mmc)
 
 static int mmci_sig_volt_switch(struct mmc_host *mmc, struct mmc_ios *ios)
 {
+       struct mmci_host *host = mmc_priv(mmc);
        int ret = 0;
 
        if (!IS_ERR(mmc->supply.vqmmc)) {
@@ -1849,6 +1854,9 @@ static int mmci_sig_volt_switch(struct mmc_host *mmc, struct mmc_ios *ios)
                        break;
                }
 
+               if (!ret && host->ops && host->ops->post_sig_volt_switch)
+                       ret = host->ops->post_sig_volt_switch(host, ios);
+
                if (ret)
                        dev_warn(mmc_dev(mmc), "Voltage switch failed\n");
        }

diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index ddcdfb8..c3bc0a3 100644 (file)
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -377,6 +377,8 @@ struct mmci_host_ops {
        void (*set_clkreg)(struct mmci_host *host, unsigned int desired);
        void (*set_pwrreg)(struct mmci_host *host, unsigned int pwr);
        bool (*busy_complete)(struct mmci_host *host, u32 status, u32 err_msk);
+       void (*pre_sig_volt_switch)(struct mmci_host *host);
+       int (*post_sig_volt_switch)(struct mmci_host *host, struct mmc_ios *ios);
 };
 
 struct mmci_host {