[PATCHv9 1/4] clk: socfpga: Add a clk-phase property to the "altr,socfpga-gate-clk"
Dinh Nguyen
dinguyen at altera.com
Fri Jan 10 10:51:51 EST 2014
Hi Seungwong,
On Fri, 2014-01-10 at 22:19 +0900, Seungwon Jeon wrote:
> Hi Dinh,
>
> On Fri, January 10, 2014, Dinh Nguyen wrote:
> > From: Dinh Nguyen <dinguyen at altera.com>
> >
> > The clk-phase property is used to represent the 2 clock phase values that is
> > needed for the SD/MMC driver. Add a prepare function to the clk_ops, that will
> > use the syscon driver to set sdmmc_clk's phase shift that is located in the
> > system manager.
> >
> > Signed-off-by: Dinh Nguyen <dinguyen at altera.com>
> > Acked-by: Zhangfei Gao <zhangfei.gao at linaro.org>
> > ---
> > v9: none
> > v8: Use degrees in the clk-phase binding property
> > v7: Add dts property to represent the clk phase of the sdmmc_clk. Add a
> > prepare function to the gate clk that will toggle clock phase setting.
> > Remove the "altr,socfpga-sdmmc-sdr-clk" clock type.
> > v6: Add a new clock type "altr,socfpga-sdmmc-sdr-clk" that will be used to
> > set the phase shift settings.
> > v5: Use the "snps,dw-mshc" binding
> > v4: Use the sdmmc_clk prepare function to set the phase shift settings
> > v3: Not use the syscon driver because as of 3.13-rc1, the syscon driver is
> > loaded after the clock driver.
> > v2: Use the syscon driver
> > ---
> > .../devicetree/bindings/clock/altr_socfpga.txt | 5 ++
> > arch/arm/boot/dts/socfpga.dtsi | 1 +
> > drivers/clk/socfpga/clk-gate.c | 68 ++++++++++++++++++++
> > 3 files changed, 74 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/clock/altr_socfpga.txt
> > b/Documentation/devicetree/bindings/clock/altr_socfpga.txt
> > index 0045433..5dfd145 100644
> > --- a/Documentation/devicetree/bindings/clock/altr_socfpga.txt
> > +++ b/Documentation/devicetree/bindings/clock/altr_socfpga.txt
> > @@ -23,3 +23,8 @@ Optional properties:
> > and the bit index.
> > - div-reg : For "socfpga-gate-clk", div-reg contains the divider register, bit shift,
> > and width.
> > +- clk-phase : For the sdmmc_clk, contains the value of the clock phase that controls
> > + the SDMMC CIU clock. The first value is the clk_sample(smpsel), and the second
> > + value is the cclk_in_drv(drvsel). The clk-phase is used to enable the correct
> > + hold/delay times that is needed for the SD/MMC CIU clock. The values of both
> > + can be 0-315 degrees, in 45 degree increments.
> > diff --git a/arch/arm/boot/dts/socfpga.dtsi b/arch/arm/boot/dts/socfpga.dtsi
> > index f936476..e776512 100644
> > --- a/arch/arm/boot/dts/socfpga.dtsi
> > +++ b/arch/arm/boot/dts/socfpga.dtsi
> > @@ -413,6 +413,7 @@
> > compatible = "altr,socfpga-gate-clk";
> > clocks = <&f2s_periph_ref_clk>, <&main_nand_sdmmc_clk>,
> > <&per_nand_mmc_clk>;
> > clk-gate = <0xa0 8>;
> > + clk-phase = <0 135>;
>
> Can clk-phase be applicable commonly for various board?
> Isn't specific timing values?
No, the clock-phase does not change for various board. It is a
SoC-specific property.
Thanks,
Dinh
>
> Thanks,
> Seungwon Jeon
> > };
> >
> > nand_x_clk: nand_x_clk {
> > diff --git a/drivers/clk/socfpga/clk-gate.c b/drivers/clk/socfpga/clk-gate.c
> > index 4efcf4e..501d513 100644
> > --- a/drivers/clk/socfpga/clk-gate.c
> > +++ b/drivers/clk/socfpga/clk-gate.c
> > @@ -19,7 +19,9 @@
> > #include <linux/clkdev.h>
> > #include <linux/clk-provider.h>
> > #include <linux/io.h>
> > +#include <linux/mfd/syscon.h>
> > #include <linux/of.h>
> > +#include <linux/regmap.h>
> >
> > #include "clk.h"
> >
> > @@ -35,6 +37,11 @@
> >
> > #define to_socfpga_gate_clk(p) container_of(p, struct socfpga_gate_clk, hw.hw)
> >
> > +/* SDMMC Group for System Manager defines */
> > +#define SYSMGR_SDMMCGRP_CTRL_OFFSET 0x108
> > +#define SYSMGR_SDMMC_CTRL_SET(smplsel, drvsel) \
> > + ((((smplsel) & 0x7) << 3) | (((drvsel) & 0x7) << 0))
> > +
> > static u8 socfpga_clk_get_parent(struct clk_hw *hwclk)
> > {
> > u32 l4_src;
> > @@ -115,7 +122,61 @@ static unsigned long socfpga_clk_recalc_rate(struct clk_hw *hwclk,
> > return parent_rate / div;
> > }
> >
> > +static int socfpga_clk_prepare(struct clk_hw *hwclk)
> > +{
> > + struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
> > + struct regmap *sys_mgr_base_addr;
> > + int i;
> > + u32 hs_timing;
> > + u32 clk_phase[2];
> > +
> > + if (socfpgaclk->clk_phase[0] || socfpgaclk->clk_phase[1]) {
> > + sys_mgr_base_addr = syscon_regmap_lookup_by_compatible("altr,sys-mgr");
> > + if (IS_ERR(sys_mgr_base_addr)) {
> > + pr_err("%s: failed to find altr,sys-mgr regmap!\n", __func__);
> > + return -EINVAL;
> > + }
> > +
> > + for (i = 0; i < 2; i++) {
> > + switch (socfpgaclk->clk_phase[i]) {
> > + case 0:
> > + clk_phase[i] = 0;
> > + break;
> > + case 45:
> > + clk_phase[i] = 1;
> > + break;
> > + case 90:
> > + clk_phase[i] = 2;
> > + break;
> > + case 135:
> > + clk_phase[i] = 3;
> > + break;
> > + case 180:
> > + clk_phase[i] = 4;
> > + break;
> > + case 225:
> > + clk_phase[i] = 5;
> > + break;
> > + case 270:
> > + clk_phase[i] = 6;
> > + break;
> > + case 315:
> > + clk_phase[i] = 7;
> > + break;
> > + default:
> > + clk_phase[i] = 0;
> > + break;
> > + }
> > + }
> > + hs_timing = SYSMGR_SDMMC_CTRL_SET(clk_phase[0], clk_phase[1]);
> > + regmap_write(sys_mgr_base_addr, SYSMGR_SDMMCGRP_CTRL_OFFSET,
> > + hs_timing);
> > + }
> > + return 0;
> > +}
> > +
> > static struct clk_ops gateclk_ops = {
> > + .prepare = socfpga_clk_prepare,
> > .recalc_rate = socfpga_clk_recalc_rate,
> > .get_parent = socfpga_clk_get_parent,
> > .set_parent = socfpga_clk_set_parent,
> > @@ -126,6 +187,7 @@ static void __init __socfpga_gate_init(struct device_node *node,
> > {
> > u32 clk_gate[2];
> > u32 div_reg[3];
> > + u32 clk_phase[2];
> > u32 fixed_div;
> > struct clk *clk;
> > struct socfpga_gate_clk *socfpga_clk;
> > @@ -166,6 +228,12 @@ static void __init __socfpga_gate_init(struct device_node *node,
> > socfpga_clk->div_reg = 0;
> > }
> >
> > + rc = of_property_read_u32_array(node, "clk-phase", clk_phase, 2);
> > + if (!rc) {
> > + socfpga_clk->clk_phase[0] = clk_phase[0];
> > + socfpga_clk->clk_phase[1] = clk_phase[1];
> > + }
> > +
> > of_property_read_string(node, "clock-output-names", &clk_name);
> >
> > init.name = clk_name;
> > --
> > 1.7.9.5
> >
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> > the body of a message to majordomo at vger.kernel.org
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
>
>
More information about the linux-arm-kernel
mailing list