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mmc: dw_mmc: Add the ability to set the ciu clock frequency

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As of now we rely on code outside of the driver to set the ciu clock
frequency.  There's no reason to do that.  Add support for setting up
the clock in the driver during probe.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
This commit is contained in:
Doug Anderson 2013-06-07 10:28:30 -07:00 committed by Chris Ball
parent 870556a3df
commit 3c6d89ea34
2 changed files with 29 additions and 4 deletions
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16
Documentation/devicetree/bindings/mmc/synopsis-dw-mshc.txt
View file

@ -39,6 +39,19 @@ Required Properties:
Optional properties:
* clocks: from common clock binding: handle to biu and ciu clocks for the
bus interface unit clock and the card interface unit clock.
* clock-names: from common clock binding: Shall be "biu" and "ciu".
If the biu clock is missing we'll simply skip enabling it. If the
ciu clock is missing we'll just assume that the clock is running at
clock-frequency. It is an error to omit both the ciu clock and the
clock-frequency.
* clock-frequency: should be the frequency (in Hz) of the ciu clock. If this
is specified and the ciu clock is specified then we'll try to set the ciu
clock to this at probe time.
* num-slots: specifies the number of slots supported by the controller.
The number of physical slots actually used could be equal or less than the
value specified by num-slots. If this property is not specified, the value
@ -70,6 +83,8 @@ board specific portions as listed below.
dwmmc0@12200000 {
compatible = "snps,dw-mshc";
clocks = <&clock 351>, <&clock 132>;
clock-names = "biu", "ciu";
reg = <0x12200000 0x1000>;
interrupts = <0 75 0>;
#address-cells = <1>;
@ -77,6 +92,7 @@ board specific portions as listed below.
};
dwmmc0@12200000 {
clock-frequency = <400000000>;
num-slots = <1>;
supports-highspeed;
broken-cd;

17
drivers/mmc/host/dw_mmc.c
View file

@ -2117,6 +2117,7 @@ static struct dw_mci_board *dw_mci_parse_dt(struct dw_mci *host)
struct device_node *np = dev->of_node;
const struct dw_mci_drv_data *drv_data = host->drv_data;
int idx, ret;
u32 clock_frequency;
pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
if (!pdata) {
@ -2143,6 +2144,9 @@ static struct dw_mci_board *dw_mci_parse_dt(struct dw_mci *host)
of_property_read_u32(np, "card-detect-delay", &pdata->detect_delay_ms);
if (!of_property_read_u32(np, "clock-frequency", &clock_frequency))
pdata->bus_hz = clock_frequency;
if (drv_data && drv_data->parse_dt) {
ret = drv_data->parse_dt(host);
if (ret)
@ -2200,18 +2204,23 @@ int dw_mci_probe(struct dw_mci *host)
host->ciu_clk = devm_clk_get(host->dev, "ciu");
if (IS_ERR(host->ciu_clk)) {
dev_dbg(host->dev, "ciu clock not available\n");
host->bus_hz = host->pdata->bus_hz;
} else {
ret = clk_prepare_enable(host->ciu_clk);
if (ret) {
dev_err(host->dev, "failed to enable ciu clock\n");
goto err_clk_biu;
}
}
if (IS_ERR(host->ciu_clk))
host->bus_hz = host->pdata->bus_hz;
else
if (host->pdata->bus_hz) {
ret = clk_set_rate(host->ciu_clk, host->pdata->bus_hz);
if (ret)
dev_warn(host->dev,
"Unable to set bus rate to %ul\n",
host->pdata->bus_hz);
}
host->bus_hz = clk_get_rate(host->ciu_clk);
}
if (drv_data && drv_data->setup_clock) {
ret = drv_data->setup_clock(host);