[PATCH 04/16] mmc: host: omap_hsmmc: Add voltage switch support for UHS SD card
Kishon Vijay Abraham I
kishon at ti.com
Fri Jun 16 05:45:32 PDT 2017
UHS SD card IO data line operates at 1.8V when in UHS speed
mode.
Add voltage switch support in order to enumerate UHS cards.
Also, enable CIRQ before checking for CLEV/DLEV. MMC module can
sense when the clock lines and data lines are driven high by the
card, if MMC is active and CIRQ can be used to keep the MMC
module active. This is required for voltage switching to succeed
and the card to enumerate in UHS mode.
Signed-off-by: Balaji T K <balajitk at ti.com>
Signed-off-by: Sourav Poddar <sourav.poddar at ti.com>
[kishon at ti.com : cleanup the voltage switch sequence]
Signed-off-by: Kishon Vijay Abraham I <kishon at ti.com>
[nsekhar at ti.com: make card busy functions preempt safe]
Signed-off-by: Sekhar Nori <nsekhar at ti.com>
---
drivers/mmc/host/omap_hsmmc.c | 179 +++++++++++++++++++++++++++++++++++++++---
1 file changed, 170 insertions(+), 9 deletions(-)
diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 65330d2263ad..680934d50919 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -44,6 +44,7 @@
#include <linux/pm_runtime.h>
#include <linux/pm_wakeirq.h>
#include <linux/platform_data/hsmmc-omap.h>
+#include <linux/mmc/sd.h>
/* OMAP HSMMC Host Controller Registers */
#define OMAP_HSMMC_SYSSTATUS 0x0014
@@ -111,6 +112,9 @@
/* PSTATE */
#define DLEV_DAT(x) (1 << (20 + (x)))
+/* AC12 */
+#define AC12_V1V8_SIGEN (1 << 19)
+
/* Interrupt masks for IE and ISE register */
#define CC_EN (1 << 0)
#define TC_EN (1 << 1)
@@ -150,6 +154,13 @@
#define VDD_1V8 1800000 /* 180000 uV */
#define VDD_3V0 3000000 /* 300000 uV */
#define VDD_165_195 (ffs(MMC_VDD_165_195) - 1)
+#define VDD_30_31 (ffs(MMC_VDD_30_31) - 1)
+
+#define CON_CLKEXTFREE (1 << 16)
+#define CON_PADEN (1 << 15)
+#define PSTATE_CLEV (1 << 24)
+#define PSTATE_DLEV (0xF << 20)
+#define PSTATE_DLEV_DAT0 (0x1 << 20)
/*
* One controller can have multiple slots, like on some omap boards using
@@ -177,6 +188,7 @@ struct omap_hsmmc_host {
struct mmc_host *mmc;
struct mmc_request *mrq;
struct mmc_command *cmd;
+ u32 last_cmd;
struct mmc_data *data;
struct clk *fclk;
struct clk *dbclk;
@@ -209,6 +221,7 @@ struct omap_hsmmc_host {
unsigned int flags;
#define AUTO_CMD23 (1 << 0) /* Auto CMD23 support */
#define HSMMC_SDIO_IRQ_ENABLED (1 << 1) /* SDIO irq enabled */
+#define CLKEXTFREE_ENABLED (1 << 2) /* CLKEXTFREE enabled */
struct omap_hsmmc_next next_data;
struct omap_hsmmc_platform_data *pdata;
@@ -593,6 +606,9 @@ static void omap_hsmmc_enable_irq(struct omap_hsmmc_host *host,
if (cmd->opcode == MMC_ERASE)
irq_mask &= ~DTO_EN;
+ if (host->flags & CLKEXTFREE_ENABLED)
+ irq_mask |= CIRQ_EN;
+
spin_lock_irqsave(&host->irq_lock, flags);
OMAP_HSMMC_WRITE(host->base, STAT, STAT_CLEAR);
OMAP_HSMMC_WRITE(host->base, ISE, irq_mask);
@@ -936,6 +952,7 @@ omap_hsmmc_start_command(struct omap_hsmmc_host *host, struct mmc_command *cmd,
cmdreg |= DMAE;
host->req_in_progress = 1;
+ host->last_cmd = cmd->opcode;
OMAP_HSMMC_WRITE(host->base, ARG, cmd->arg);
OMAP_HSMMC_WRITE(host->base, CMD, cmdreg);
@@ -1735,17 +1752,12 @@ static void omap_hsmmc_set_capabilities(struct omap_hsmmc_host *host)
OMAP_HSMMC_WRITE(host->base, CAPA, val);
}
-static void omap_hsmmc_conf_bus_power(struct omap_hsmmc_host *host)
+static void omap_hsmmc_conf_bus_power(struct omap_hsmmc_host *host, int iov)
{
u32 hctl, value;
- /* Only MMC1 supports 3.0V */
- if (host->pdata->controller_flags & OMAP_HSMMC_SUPPORTS_DUAL_VOLT)
- hctl = SDVS30;
- else
- hctl = SDVS18;
-
value = OMAP_HSMMC_READ(host->base, HCTL) & ~SDVS_MASK;
+ hctl = (iov == MMC_SIGNAL_VOLTAGE_180) ? SDVS18 : SDVS30;
OMAP_HSMMC_WRITE(host->base, HCTL, value | hctl);
/* Set SD bus power bit */
@@ -1762,6 +1774,152 @@ static int omap_hsmmc_multi_io_quirk(struct mmc_card *card,
return blk_size;
}
+static int omap_hsmmc_start_signal_voltage_switch(struct mmc_host *mmc,
+ struct mmc_ios *ios)
+{
+ struct omap_hsmmc_host *host;
+ u32 val = 0;
+ int ret = 0;
+
+ host = mmc_priv(mmc);
+
+ if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330) {
+ val = OMAP_HSMMC_READ(host->base, CAPA);
+ if (!(val & VS30))
+ return -EOPNOTSUPP;
+
+ omap_hsmmc_conf_bus_power(host, ios->signal_voltage);
+
+ val = OMAP_HSMMC_READ(host->base, AC12);
+ val &= ~AC12_V1V8_SIGEN;
+ OMAP_HSMMC_WRITE(host->base, AC12, val);
+
+ ret = omap_hsmmc_set_power(host, 1, VDD_30_31);
+ if (ret) {
+ dev_err(mmc_dev(host->mmc), "failed to switch to 3v\n");
+ return ret;
+ }
+
+ dev_dbg(mmc_dev(host->mmc), " i/o voltage switch to 3V\n");
+ } else if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180) {
+ val = OMAP_HSMMC_READ(host->base, CAPA);
+ if (!(val & VS18))
+ return -EOPNOTSUPP;
+
+ omap_hsmmc_conf_bus_power(host, ios->signal_voltage);
+
+ val = OMAP_HSMMC_READ(host->base, AC12);
+ val |= AC12_V1V8_SIGEN;
+ OMAP_HSMMC_WRITE(host->base, AC12, val);
+
+ ret = omap_hsmmc_set_power(host, 1, VDD_165_195);
+ if (ret < 0) {
+ dev_err(mmc_dev(host->mmc), "failed to switch 1.8v\n");
+ return ret;
+ }
+ } else {
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
+static int omap_hsmmc_card_busy_low(struct omap_hsmmc_host *host)
+{
+ int i;
+ u32 val;
+
+ val = OMAP_HSMMC_READ(host->base, CON);
+ val &= ~CON_CLKEXTFREE;
+ val |= CON_PADEN;
+ OMAP_HSMMC_WRITE(host->base, CON, val);
+
+ /* By observation, card busy status reflects in 100 - 200us */
+ for (i = 0; i < 5; i++) {
+ val = OMAP_HSMMC_READ(host->base, PSTATE);
+ if (!(val & (PSTATE_CLEV | PSTATE_DLEV)))
+ return true;
+
+ usleep_range(100, 200);
+ }
+
+ dev_err(mmc_dev(host->mmc), "card busy\n");
+
+ return false;
+}
+
+static int omap_hsmmc_card_busy_high(struct omap_hsmmc_host *host)
+{
+ int i;
+ u32 val;
+ int ret = true;
+
+ val = OMAP_HSMMC_READ(host->base, CON);
+ val |= CLKEXTFREE;
+ OMAP_HSMMC_WRITE(host->base, CON, val);
+
+ host->flags |= CLKEXTFREE_ENABLED;
+ disable_irq(host->irq);
+ omap_hsmmc_enable_irq(host, NULL);
+
+ /* By observation, card busy status reflects in 100 - 200us */
+ for (i = 0; i < 5; i++) {
+ val = OMAP_HSMMC_READ(host->base, PSTATE);
+ if ((val & PSTATE_CLEV) && (val & PSTATE_DLEV)) {
+ val = OMAP_HSMMC_READ(host->base, CON);
+ val &= ~(CON_CLKEXTFREE | CON_PADEN);
+ OMAP_HSMMC_WRITE(host->base, CON, val);
+ ret = false;
+ goto disable_irq;
+ }
+
+ usleep_range(100, 200);
+ }
+
+ dev_err(mmc_dev(host->mmc), "card busy\n");
+
+disable_irq:
+ omap_hsmmc_disable_irq(host);
+ enable_irq(host->irq);
+ host->flags &= ~CLKEXTFREE_ENABLED;
+
+ return ret;
+}
+
+static int omap_hsmmc_card_busy(struct mmc_host *mmc)
+{
+ struct omap_hsmmc_host *host;
+ u32 val;
+ u32 reg;
+ int ret;
+
+ host = mmc_priv(mmc);
+
+ if (host->last_cmd != SD_SWITCH_VOLTAGE) {
+ /*
+ * PADEN should be set for DLEV to reflect the correct
+ * state of data lines atleast for MMC1 on AM57x.
+ */
+ reg = OMAP_HSMMC_READ(host->base, CON);
+ reg |= CON_PADEN;
+ OMAP_HSMMC_WRITE(host->base, CON, reg);
+ val = OMAP_HSMMC_READ(host->base, PSTATE);
+ reg &= ~CON_PADEN;
+ OMAP_HSMMC_WRITE(host->base, CON, reg);
+ if (val & PSTATE_DLEV_DAT0)
+ return false;
+ return true;
+ }
+
+ val = OMAP_HSMMC_READ(host->base, AC12);
+ if (val & AC12_V1V8_SIGEN)
+ ret = omap_hsmmc_card_busy_high(host);
+ else
+ ret = omap_hsmmc_card_busy_low(host);
+
+ return ret;
+}
+
static struct mmc_host_ops omap_hsmmc_ops = {
.post_req = omap_hsmmc_post_req,
.pre_req = omap_hsmmc_pre_req,
@@ -1771,6 +1929,8 @@ static struct mmc_host_ops omap_hsmmc_ops = {
.get_ro = mmc_gpio_get_ro,
.init_card = omap_hsmmc_init_card,
.enable_sdio_irq = omap_hsmmc_enable_sdio_irq,
+ .start_signal_voltage_switch = omap_hsmmc_start_signal_voltage_switch,
+ .card_busy = omap_hsmmc_card_busy,
};
#ifdef CONFIG_DEBUG_FS
@@ -2055,7 +2215,6 @@ static int omap_hsmmc_probe(struct platform_device *pdev)
mmc->pm_caps |= mmc_pdata(host)->pm_caps;
omap_hsmmc_set_capabilities(host);
- omap_hsmmc_conf_bus_power(host);
host->rx_chan = dma_request_chan(&pdev->dev, "rx");
if (IS_ERR(host->rx_chan)) {
@@ -2193,6 +2352,7 @@ static int omap_hsmmc_suspend(struct device *dev)
static int omap_hsmmc_resume(struct device *dev)
{
struct omap_hsmmc_host *host = dev_get_drvdata(dev);
+ struct mmc_ios *ios;
if (!host)
return 0;
@@ -2202,8 +2362,9 @@ static int omap_hsmmc_resume(struct device *dev)
if (host->dbclk)
clk_prepare_enable(host->dbclk);
+ ios = &host->mmc->ios;
if (!(host->mmc->pm_flags & MMC_PM_KEEP_POWER))
- omap_hsmmc_conf_bus_power(host);
+ omap_hsmmc_conf_bus_power(host, ios->signal_voltage);
omap_hsmmc_protect_card(host);
pm_runtime_mark_last_busy(host->dev);
--
2.11.0
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