From: Dinh Nguyen <dinguyen@xxxxxxxxxx>
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@xxxxxxxxxx>
Acked-by: Zhangfei Gao <zhangfei.gao@xxxxxxxxxx>
---
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>;
};
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
--
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