mmc: msm_sdcc: set IO_PAD_PWR_SWITCH bit based on IO voltage level
SDCC4 controller has IO_PAD_PWR_SWITCH control bit in MCI_CLK register.
Driver should set this bit to 1 if the IO voltage level is within
low voltage range (1.7v - 1.9v) else clear it.
But driver sets this bit to 1 only if the MMC core layer initiates
the voltage switch sequence. So if voltage switch sequence is not
initiated (which is the case with non UHS-I cards) then even if
the IO voltage level is within low voltage range, IO_PAD_PWR_SWITCH
bit remains cleared.
This change checks the IO voltage level and based on that sets the
IO_PAD_PWR_SWITCH bit.
CRs-Fixed: 386445
Change-Id: Id0648b0f87ea9bcc942e855e30da810e0fe5ebf5
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
diff --git a/drivers/mmc/host/msm_sdcc.c b/drivers/mmc/host/msm_sdcc.c
index a033693..b8db530 100644
--- a/drivers/mmc/host/msm_sdcc.c
+++ b/drivers/mmc/host/msm_sdcc.c
@@ -2172,6 +2172,18 @@
return rc;
}
+static inline int msmsdcc_vreg_get_voltage(struct msm_mmc_reg_data *vreg)
+{
+ int rc = 0;
+
+ rc = regulator_get_voltage(vreg->reg);
+ if (rc < 0)
+ pr_err("%s: regulator_get_voltage(%s) failed. rc=%d\n",
+ __func__, vreg->name, rc);
+
+ return rc;
+}
+
static inline int msmsdcc_vreg_set_optimum_mode(struct msm_mmc_reg_data *vreg,
int uA_load)
{
@@ -2416,6 +2428,82 @@
VDD_IO_SET_LEVEL,
};
+/*
+ * This function returns the current VDD IO voltage level.
+ * Returns negative value if it fails to read the voltage level
+ * Returns 0 if regulator was disabled or if VDD_IO (and VDD)
+ * regulator were not defined for host.
+ */
+static int msmsdcc_get_vdd_io_vol(struct msmsdcc_host *host)
+{
+ int rc = 0;
+
+ if (host->plat->vreg_data) {
+ struct msm_mmc_reg_data *io_reg =
+ host->plat->vreg_data->vdd_io_data;
+
+ /*
+ * If vdd_io is not defined, then we can consider that
+ * IO voltage is same as VDD.
+ */
+ if (!io_reg)
+ io_reg = host->plat->vreg_data->vdd_data;
+
+ if (io_reg && io_reg->is_enabled)
+ rc = msmsdcc_vreg_get_voltage(io_reg);
+ }
+
+ return rc;
+}
+
+/*
+ * This function updates the IO pad power switch bit in MCI_CLK register
+ * based on currrent IO pad voltage level.
+ * NOTE: This function assumes that host lock was not taken by caller.
+ */
+static void msmsdcc_update_io_pad_pwr_switch(struct msmsdcc_host *host)
+{
+ int rc = 0;
+ unsigned long flags;
+
+ if (!is_io_pad_pwr_switch(host))
+ return;
+
+ rc = msmsdcc_get_vdd_io_vol(host);
+
+ spin_lock_irqsave(&host->lock, flags);
+ /*
+ * Dual voltage pad is the SDCC's (chipset) functionality and not all
+ * the SDCC instances support the dual voltage pads.
+ * For dual-voltage pad (1.8v/3.3v), SW should set IO_PAD_PWR_SWITCH
+ * bit before using the pads in 1.8V mode.
+ * For regular, not dual-voltage pads (including eMMC 1.2v/1.8v pads),
+ * IO_PAD_PWR_SWITCH bit is a don't care.
+ * But we don't have an option to know (by reading some SDCC register)
+ * that a particular SDCC instance supports dual voltage pads or not,
+ * so we simply set the IO_PAD_PWR_SWITCH bit for low voltage IO
+ * (1.8v/1.2v). For regular (not dual-voltage pads), this bit value
+ * is anyway ignored.
+ */
+ if (rc > 0 && rc < 2700000)
+ host->io_pad_pwr_switch = 1;
+ else
+ host->io_pad_pwr_switch = 0;
+
+ if (atomic_read(&host->clks_on)) {
+ if (host->io_pad_pwr_switch)
+ writel_relaxed((readl_relaxed(host->base + MMCICLOCK) |
+ IO_PAD_PWR_SWITCH),
+ host->base + MMCICLOCK);
+ else
+ writel_relaxed((readl_relaxed(host->base + MMCICLOCK) &
+ ~IO_PAD_PWR_SWITCH),
+ host->base + MMCICLOCK);
+ msmsdcc_sync_reg_wr(host);
+ }
+ spin_unlock_irqrestore(&host->lock, flags);
+}
+
static int msmsdcc_set_vdd_io_vol(struct msmsdcc_host *host,
enum vdd_io_level level,
unsigned int voltage_level)
@@ -2717,6 +2805,7 @@
* present or during system suspend).
*/
msmsdcc_set_vdd_io_vol(host, VDD_IO_LOW, 0);
+ msmsdcc_update_io_pad_pwr_switch(host);
msmsdcc_setup_pins(host, false);
break;
case MMC_POWER_UP:
@@ -2725,6 +2814,7 @@
msmsdcc_cfg_mpm_sdiowakeup(host, SDC_DAT1_ENABLE);
msmsdcc_set_vdd_io_vol(host, VDD_IO_HIGH, 0);
+ msmsdcc_update_io_pad_pwr_switch(host);
msmsdcc_setup_pins(host, true);
break;
case MMC_POWER_ON:
@@ -3137,10 +3227,6 @@
/* Select free running MCLK as input clock of cm_dll_sdc4 */
clk |= (2 << 23);
- /* Clear IO_PAD_PWR_SWITCH while powering off the card */
- if (!ios->vdd)
- host->io_pad_pwr_switch = 0;
-
if (host->io_pad_pwr_switch)
clk |= IO_PAD_PWR_SWITCH;
@@ -3429,14 +3515,12 @@
unsigned long flags;
int rc = 0;
- spin_lock_irqsave(&host->lock, flags);
- host->io_pad_pwr_switch = 0;
- spin_unlock_irqrestore(&host->lock, flags);
-
switch (ios->signal_voltage) {
case MMC_SIGNAL_VOLTAGE_330:
/* Set VDD IO to high voltage range (2.7v - 3.6v) */
rc = msmsdcc_set_vdd_io_vol(host, VDD_IO_HIGH, 0);
+ if (!rc)
+ msmsdcc_update_io_pad_pwr_switch(host);
goto out;
case MMC_SIGNAL_VOLTAGE_180:
break;
@@ -3447,6 +3531,8 @@
* DDR 1.2V mode.
*/
rc = msmsdcc_set_vdd_io_vol(host, VDD_IO_SET_LEVEL, 1200000);
+ if (!rc)
+ msmsdcc_update_io_pad_pwr_switch(host);
goto out;
default:
/* invalid selection. don't do anything */
@@ -3485,12 +3571,7 @@
if (rc)
goto out;
- spin_lock_irqsave(&host->lock, flags);
- writel_relaxed((readl_relaxed(host->base + MMCICLOCK) |
- IO_PAD_PWR_SWITCH), host->base + MMCICLOCK);
- msmsdcc_sync_reg_wr(host);
- host->io_pad_pwr_switch = 1;
- spin_unlock_irqrestore(&host->lock, flags);
+ msmsdcc_update_io_pad_pwr_switch(host);
/* Wait 5 ms for the voltage regulater in the card to become stable. */
usleep_range(5000, 5500);
diff --git a/drivers/mmc/host/msm_sdcc.h b/drivers/mmc/host/msm_sdcc.h
index 3b1dbc7..236785d 100644
--- a/drivers/mmc/host/msm_sdcc.h
+++ b/drivers/mmc/host/msm_sdcc.h
@@ -428,6 +428,7 @@
#define MSMSDCC_SW_RST (1 << 5)
#define MSMSDCC_SW_RST_CFG (1 << 6)
#define MSMSDCC_WAIT_FOR_TX_RX (1 << 7)
+#define MSMSDCC_IO_PAD_PWR_SWITCH (1 << 8)
#define set_hw_caps(h, val) ((h)->hw_caps |= val)
#define is_sps_mode(h) ((h)->hw_caps & MSMSDCC_SPS_BAM_SUP)
@@ -438,6 +439,7 @@
#define is_sw_hard_reset(h) ((h)->hw_caps & MSMSDCC_SW_RST)
#define is_sw_reset_save_config(h) ((h)->hw_caps & MSMSDCC_SW_RST_CFG)
#define is_wait_for_tx_rx_active(h) ((h)->hw_caps & MSMSDCC_WAIT_FOR_TX_RX)
+#define is_io_pad_pwr_switch(h) ((h)->hw_caps & MSMSDCC_IO_PAD_PWR_SWITCH)
/* Set controller capabilities based on version */
static inline void set_default_hw_caps(struct msmsdcc_host *host)
@@ -457,7 +459,7 @@
if (version) /* SDCC v4 and greater */
host->hw_caps |= MSMSDCC_AUTO_PROG_DONE |
MSMSDCC_SOFT_RESET | MSMSDCC_REG_WR_ACTIVE
- | MSMSDCC_WAIT_FOR_TX_RX;
+ | MSMSDCC_WAIT_FOR_TX_RX | MSMSDCC_IO_PAD_PWR_SWITCH;
if (version >= 0x2D) /* SDCC v4 2.1.0 and greater */
host->hw_caps |= MSMSDCC_SW_RST | MSMSDCC_SW_RST_CFG;