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authorThomas Abraham <thomas.abraham@linaro.org>2012-09-17 22:16:38 +0400
committerChris Ball <cjb@laptop.org>2012-10-03 18:05:15 +0400
commitf90a0612f0e110a8af976835273124dff4fa8b3d (patch)
treeef683e834a1cf4780c00fad28f88603fda15a159
parent1c2215b7c6f20a65877431a5ebb4f9a789df3811 (diff)
downloadlinux-f90a0612f0e110a8af976835273124dff4fa8b3d.tar.xz
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>
-rw-r--r--drivers/mmc/host/dw_mmc.c52
-rw-r--r--include/linux/mmc/dw_mmc.h4
2 files changed, 53 insertions, 3 deletions
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 227c42ef18c5..de45ad24becb 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1960,13 +1960,42 @@ int dw_mci_probe(struct dw_mci *host)
return -ENODEV;
}
- if (!host->pdata->bus_hz) {
+ 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->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");
- return -ENODEV;
+ ret = -ENODEV;
+ goto err_clk_ciu;
}
- host->bus_hz = host->pdata->bus_hz;
host->quirks = host->pdata->quirks;
spin_lock_init(&host->lock);
@@ -2116,6 +2145,17 @@ err_dmaunmap:
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 @@ void dw_mci_remove(struct dw_mci *host)
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);
diff --git a/include/linux/mmc/dw_mmc.h b/include/linux/mmc/dw_mmc.h
index a37a573fa13c..787ad569c99b 100644
--- a/include/linux/mmc/dw_mmc.h
+++ b/include/linux/mmc/dw_mmc.h
@@ -78,6 +78,8 @@ struct mmc_data;
* @data_offset: Set the offset of DATA register according to VERID.
* @dev: Device associated with the MMC controller.
* @pdata: Platform data associated with the MMC controller.
+ * @biu_clk: Pointer to bus interface unit clock instance.
+ * @ciu_clk: Pointer to card interface unit clock instance.
* @slot: Slots sharing this MMC controller.
* @fifo_depth: depth of FIFO.
* @data_shift: log2 of FIFO item size.
@@ -158,6 +160,8 @@ struct dw_mci {
u16 data_offset;
struct device *dev;
struct dw_mci_board *pdata;
+ struct clk *biu_clk;
+ struct clk *ciu_clk;
struct dw_mci_slot *slot[MAX_MCI_SLOTS];
/* FIFO push and pull */