[PATCHv9 1/4] clk: socfpga: Add a clk-phase property to the "altr,socfpga-gate-clk"
From: <hidden>
Date: 2014-01-09 21:31:16
Also in:
linux-arm-kernel, linux-mmc
Subsystem:
arm/socfpga clock framework support, common clk framework, open firmware and flattened device tree bindings, the rest · Maintainers:
Dinh Nguyen, Michael Turquette, Stephen Boyd, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds
From: Dinh Nguyen <redacted>
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 <redacted>
Acked-by: Zhangfei Gao <redacted>
---
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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