mmc: dw_mmc: lookup for optional biu and ciu clocks
Some platforms allow for clock gating and control of bus interface unit
clock and card interface unit clock. Add support for clock lookup of
optional biu and ciu clocks for clock gating and clock speed
determination.
Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Acked-by: Will Newton <will.newton@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 227c42e..de45ad2 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1960,13 +1960,42 @@
return -ENODEV;
}
- if (!host->pdata->bus_hz) {
- dev_err(host->dev,
- "Platform data must supply bus speed\n");
- return -ENODEV;
+ host->biu_clk = clk_get(host->dev, "biu");
+ if (IS_ERR(host->biu_clk)) {
+ dev_dbg(host->dev, "biu clock not available\n");
+ } else {
+ ret = clk_prepare_enable(host->biu_clk);
+ if (ret) {
+ dev_err(host->dev, "failed to enable biu clock\n");
+ clk_put(host->biu_clk);
+ return ret;
+ }
}
- host->bus_hz = host->pdata->bus_hz;
+ host->ciu_clk = clk_get(host->dev, "ciu");
+ if (IS_ERR(host->ciu_clk)) {
+ dev_dbg(host->dev, "ciu clock not available\n");
+ } else {
+ ret = clk_prepare_enable(host->ciu_clk);
+ if (ret) {
+ dev_err(host->dev, "failed to enable ciu clock\n");
+ clk_put(host->ciu_clk);
+ goto err_clk_biu;
+ }
+ }
+
+ if (IS_ERR(host->ciu_clk))
+ host->bus_hz = host->pdata->bus_hz;
+ else
+ host->bus_hz = clk_get_rate(host->ciu_clk);
+
+ if (!host->bus_hz) {
+ dev_err(host->dev,
+ "Platform data must supply bus speed\n");
+ ret = -ENODEV;
+ goto err_clk_ciu;
+ }
+
host->quirks = host->pdata->quirks;
spin_lock_init(&host->lock);
@@ -2116,6 +2145,17 @@
regulator_disable(host->vmmc);
regulator_put(host->vmmc);
}
+
+err_clk_ciu:
+ if (!IS_ERR(host->ciu_clk)) {
+ clk_disable_unprepare(host->ciu_clk);
+ clk_put(host->ciu_clk);
+ }
+err_clk_biu:
+ if (!IS_ERR(host->biu_clk)) {
+ clk_disable_unprepare(host->biu_clk);
+ clk_put(host->biu_clk);
+ }
return ret;
}
EXPORT_SYMBOL(dw_mci_probe);
@@ -2149,6 +2189,12 @@
regulator_put(host->vmmc);
}
+ if (!IS_ERR(host->ciu_clk))
+ clk_disable_unprepare(host->ciu_clk);
+ if (!IS_ERR(host->biu_clk))
+ clk_disable_unprepare(host->biu_clk);
+ clk_put(host->ciu_clk);
+ clk_put(host->biu_clk);
}
EXPORT_SYMBOL(dw_mci_remove);