* [PATCH 0/4] ARM: imx6q: clean up board specific CLKO setup
@ 2013-07-18 7:31 Shawn Guo
2013-07-18 7:31 ` [PATCH 1/4] ARM: imx6q: add spdif gate clock Shawn Guo
` (3 more replies)
0 siblings, 4 replies; 7+ messages in thread
From: Shawn Guo @ 2013-07-18 7:31 UTC (permalink / raw)
To: linux-arm-kernel
The CLKO is widely used by imx6q board designs to clock audio codec.
Currently, imx6q-sabrelite and imx6qdl-sabresd set up CLKO in board
specific hooks, while imx6qdl-wandboard handles that in U-Boot.
Since most audio codecs accept 24 MHz frequency, the series adds missing
CLKO pieces into clock driver, and initially sets up CLKO with OSC24M
(cko <-- cko2 <-- osc). Then those board specific CLKO setup for audio
codec can be removed, while it improves the power efficiency@the same
time by saving the use of PLL.
Shawn
Shawn Guo (4):
ARM: imx6q: add spdif gate clock
ARM: imx6q: add cko2 clocks
ARM: imx6q: add the missing cko output selection
ARM: imx6q: remove board specific CLKO setup
.../devicetree/bindings/clock/imx6q-clock.txt | 5 ++
arch/arm/boot/dts/imx6q-sabrelite.dts | 2 +-
arch/arm/boot/dts/imx6qdl-sabresd.dtsi | 2 +-
arch/arm/boot/dts/imx6qdl-wandboard.dtsi | 2 +-
arch/arm/mach-imx/clk-imx6q.c | 30 ++++++++-
arch/arm/mach-imx/mach-imx6q.c | 69 --------------------
6 files changed, 37 insertions(+), 73 deletions(-)
--
1.7.9.5
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH 1/4] ARM: imx6q: add spdif gate clock
2013-07-18 7:31 [PATCH 0/4] ARM: imx6q: clean up board specific CLKO setup Shawn Guo
@ 2013-07-18 7:31 ` Shawn Guo
2013-07-18 7:31 ` [PATCH 2/4] ARM: imx6q: add cko2 clocks Shawn Guo
` (2 subsequent siblings)
3 siblings, 0 replies; 7+ messages in thread
From: Shawn Guo @ 2013-07-18 7:31 UTC (permalink / raw)
To: linux-arm-kernel
It adds the missing spdif gate clock into imx6q clock driver.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
---
.../devicetree/bindings/clock/imx6q-clock.txt | 1 +
arch/arm/mach-imx/clk-imx6q.c | 4 +++-
2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/Documentation/devicetree/bindings/clock/imx6q-clock.txt b/Documentation/devicetree/bindings/clock/imx6q-clock.txt
index a0e104f..794d089 100644
--- a/Documentation/devicetree/bindings/clock/imx6q-clock.txt
+++ b/Documentation/devicetree/bindings/clock/imx6q-clock.txt
@@ -209,6 +209,7 @@ clocks and IDs.
pll5_post_div 194
pll5_video_div 195
eim_slow 196
+ spdif 197
Examples:
diff --git a/arch/arm/mach-imx/clk-imx6q.c b/arch/arm/mach-imx/clk-imx6q.c
index db9f8f5..d739df1 100644
--- a/arch/arm/mach-imx/clk-imx6q.c
+++ b/arch/arm/mach-imx/clk-imx6q.c
@@ -239,7 +239,8 @@ enum mx6q_clks {
pll4_audio, pll5_video, pll8_mlb, pll7_usb_host, pll6_enet, ssi1_ipg,
ssi2_ipg, ssi3_ipg, rom, usbphy1, usbphy2, ldb_di0_div_3_5, ldb_di1_div_3_5,
sata_ref, sata_ref_100m, pcie_ref, pcie_ref_125m, enet_ref, usbphy1_gate,
- usbphy2_gate, pll4_post_div, pll5_post_div, pll5_video_div, eim_slow, clk_max
+ usbphy2_gate, pll4_post_div, pll5_post_div, pll5_video_div, eim_slow,
+ spdif, clk_max
};
static struct clk *clk[clk_max];
@@ -521,6 +522,7 @@ static void __init imx6q_clocks_init(struct device_node *ccm_node)
clk[sata] = imx_clk_gate2("sata", "ipg", base + 0x7c, 4);
clk[sdma] = imx_clk_gate2("sdma", "ahb", base + 0x7c, 6);
clk[spba] = imx_clk_gate2("spba", "ipg", base + 0x7c, 12);
+ clk[spdif] = imx_clk_gate2("spdif", "spdif_podf", base + 0x7c, 14);
clk[ssi1_ipg] = imx_clk_gate2("ssi1_ipg", "ipg", base + 0x7c, 18);
clk[ssi2_ipg] = imx_clk_gate2("ssi2_ipg", "ipg", base + 0x7c, 20);
clk[ssi3_ipg] = imx_clk_gate2("ssi3_ipg", "ipg", base + 0x7c, 22);
--
1.7.9.5
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH 2/4] ARM: imx6q: add cko2 clocks
2013-07-18 7:31 [PATCH 0/4] ARM: imx6q: clean up board specific CLKO setup Shawn Guo
2013-07-18 7:31 ` [PATCH 1/4] ARM: imx6q: add spdif gate clock Shawn Guo
@ 2013-07-18 7:31 ` Shawn Guo
2013-07-18 7:31 ` [PATCH 3/4] ARM: imx6q: add the missing cko output selection Shawn Guo
2013-07-18 7:31 ` [PATCH 4/4] ARM: imx6q: remove board specific CLKO setup Shawn Guo
3 siblings, 0 replies; 7+ messages in thread
From: Shawn Guo @ 2013-07-18 7:31 UTC (permalink / raw)
To: linux-arm-kernel
It adds the missing cko2 clocks, including multiplexer, divider and
gate.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
---
.../devicetree/bindings/clock/imx6q-clock.txt | 3 +++
arch/arm/mach-imx/clk-imx6q.c | 15 ++++++++++++++-
2 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/Documentation/devicetree/bindings/clock/imx6q-clock.txt b/Documentation/devicetree/bindings/clock/imx6q-clock.txt
index 794d089..c6d7e16 100644
--- a/Documentation/devicetree/bindings/clock/imx6q-clock.txt
+++ b/Documentation/devicetree/bindings/clock/imx6q-clock.txt
@@ -210,6 +210,9 @@ clocks and IDs.
pll5_video_div 195
eim_slow 196
spdif 197
+ cko2_sel 198
+ cko2_podf 199
+ cko2 200
Examples:
diff --git a/arch/arm/mach-imx/clk-imx6q.c b/arch/arm/mach-imx/clk-imx6q.c
index d739df1..924ed84 100644
--- a/arch/arm/mach-imx/clk-imx6q.c
+++ b/arch/arm/mach-imx/clk-imx6q.c
@@ -206,6 +206,16 @@ static const char *vpu_axi_sels[] = { "axi", "pll2_pfd2_396m", "pll2_pfd0_352m",
static const char *cko1_sels[] = { "pll3_usb_otg", "pll2_bus", "pll1_sys", "pll5_video_div",
"dummy", "axi", "enfc", "ipu1_di0", "ipu1_di1", "ipu2_di0",
"ipu2_di1", "ahb", "ipg", "ipg_per", "ckil", "pll4_post_div", };
+static const char *cko2_sels[] = {
+ "mmdc_ch0_axi", "mmdc_ch1_axi", "usdhc4", "usdhc1",
+ "gpu2d_axi", "dummy", "ecspi_root", "gpu3d_axi",
+ "usdhc3", "dummy", "arm", "ipu1",
+ "ipu2", "vdo_axi", "osc", "gpu2d_core",
+ "gpu3d_core", "usdhc2", "ssi1", "ssi2",
+ "ssi3", "gpu3d_shader", "vpu_axi", "can_root",
+ "ldb_di0", "ldb_di1", "esai", "eim_slow",
+ "uart_serial", "spdif", "asrc", "hsi_tx",
+};
enum mx6q_clks {
dummy, ckil, ckih, osc, pll2_pfd0_352m, pll2_pfd1_594m, pll2_pfd2_396m,
@@ -240,7 +250,7 @@ enum mx6q_clks {
ssi2_ipg, ssi3_ipg, rom, usbphy1, usbphy2, ldb_di0_div_3_5, ldb_di1_div_3_5,
sata_ref, sata_ref_100m, pcie_ref, pcie_ref_125m, enet_ref, usbphy1_gate,
usbphy2_gate, pll4_post_div, pll5_post_div, pll5_video_div, eim_slow,
- spdif, clk_max
+ spdif, cko2_sel, cko2_podf, cko2, clk_max
};
static struct clk *clk[clk_max];
@@ -398,6 +408,7 @@ static void __init imx6q_clocks_init(struct device_node *ccm_node)
clk[vdo_axi_sel] = imx_clk_mux("vdo_axi_sel", base + 0x18, 11, 1, vdo_axi_sels, ARRAY_SIZE(vdo_axi_sels));
clk[vpu_axi_sel] = imx_clk_mux("vpu_axi_sel", base + 0x18, 14, 2, vpu_axi_sels, ARRAY_SIZE(vpu_axi_sels));
clk[cko1_sel] = imx_clk_mux("cko1_sel", base + 0x60, 0, 4, cko1_sels, ARRAY_SIZE(cko1_sels));
+ clk[cko2_sel] = imx_clk_mux("cko2_sel", base + 0x60, 16, 5, cko2_sels, ARRAY_SIZE(cko2_sels));
/* name reg shift width busy: reg, shift parent_names num_parents */
clk[periph] = imx_clk_busy_mux("periph", base + 0x14, 25, 1, base + 0x48, 5, periph_sels, ARRAY_SIZE(periph_sels));
@@ -447,6 +458,7 @@ static void __init imx6q_clocks_init(struct device_node *ccm_node)
clk[emi_slow_podf] = imx_clk_fixup_divider("emi_slow_podf", "emi_slow_sel", base + 0x1c, 23, 3, imx_cscmr1_fixup);
clk[vpu_axi_podf] = imx_clk_divider("vpu_axi_podf", "vpu_axi_sel", base + 0x24, 25, 3);
clk[cko1_podf] = imx_clk_divider("cko1_podf", "cko1_sel", base + 0x60, 4, 3);
+ clk[cko2_podf] = imx_clk_divider("cko2_podf", "cko2_sel", base + 0x60, 21, 3);
/* name parent_name reg shift width busy: reg, shift */
clk[axi] = imx_clk_busy_divider("axi", "axi_sel", base + 0x14, 16, 3, base + 0x48, 0);
@@ -537,6 +549,7 @@ static void __init imx6q_clocks_init(struct device_node *ccm_node)
clk[vdo_axi] = imx_clk_gate2("vdo_axi", "vdo_axi_sel", base + 0x80, 12);
clk[vpu_axi] = imx_clk_gate2("vpu_axi", "vpu_axi_podf", base + 0x80, 14);
clk[cko1] = imx_clk_gate("cko1", "cko1_podf", base + 0x60, 7);
+ clk[cko2] = imx_clk_gate("cko2", "cko2_podf", base + 0x60, 24);
for (i = 0; i < ARRAY_SIZE(clk); i++)
if (IS_ERR(clk[i]))
--
1.7.9.5
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH 3/4] ARM: imx6q: add the missing cko output selection
2013-07-18 7:31 [PATCH 0/4] ARM: imx6q: clean up board specific CLKO setup Shawn Guo
2013-07-18 7:31 ` [PATCH 1/4] ARM: imx6q: add spdif gate clock Shawn Guo
2013-07-18 7:31 ` [PATCH 2/4] ARM: imx6q: add cko2 clocks Shawn Guo
@ 2013-07-18 7:31 ` Shawn Guo
2013-07-18 7:31 ` [PATCH 4/4] ARM: imx6q: remove board specific CLKO setup Shawn Guo
3 siblings, 0 replies; 7+ messages in thread
From: Shawn Guo @ 2013-07-18 7:31 UTC (permalink / raw)
To: linux-arm-kernel
The clock output on imx6q CCM_CLKO1 pad is not always cko1 clock, and
there is a multiplexer to select between cko1 and cko2. Add this
missing selection as the clock cko.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
---
.../devicetree/bindings/clock/imx6q-clock.txt | 1 +
arch/arm/mach-imx/clk-imx6q.c | 4 +++-
2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/Documentation/devicetree/bindings/clock/imx6q-clock.txt b/Documentation/devicetree/bindings/clock/imx6q-clock.txt
index c6d7e16..3066f181 100644
--- a/Documentation/devicetree/bindings/clock/imx6q-clock.txt
+++ b/Documentation/devicetree/bindings/clock/imx6q-clock.txt
@@ -213,6 +213,7 @@ clocks and IDs.
cko2_sel 198
cko2_podf 199
cko2 200
+ cko 201
Examples:
diff --git a/arch/arm/mach-imx/clk-imx6q.c b/arch/arm/mach-imx/clk-imx6q.c
index 924ed84..ed19b33 100644
--- a/arch/arm/mach-imx/clk-imx6q.c
+++ b/arch/arm/mach-imx/clk-imx6q.c
@@ -216,6 +216,7 @@ static const char *cko2_sels[] = {
"ldb_di0", "ldb_di1", "esai", "eim_slow",
"uart_serial", "spdif", "asrc", "hsi_tx",
};
+static const char *cko_sels[] = { "cko1", "cko2", };
enum mx6q_clks {
dummy, ckil, ckih, osc, pll2_pfd0_352m, pll2_pfd1_594m, pll2_pfd2_396m,
@@ -250,7 +251,7 @@ enum mx6q_clks {
ssi2_ipg, ssi3_ipg, rom, usbphy1, usbphy2, ldb_di0_div_3_5, ldb_di1_div_3_5,
sata_ref, sata_ref_100m, pcie_ref, pcie_ref_125m, enet_ref, usbphy1_gate,
usbphy2_gate, pll4_post_div, pll5_post_div, pll5_video_div, eim_slow,
- spdif, cko2_sel, cko2_podf, cko2, clk_max
+ spdif, cko2_sel, cko2_podf, cko2, cko, clk_max
};
static struct clk *clk[clk_max];
@@ -409,6 +410,7 @@ static void __init imx6q_clocks_init(struct device_node *ccm_node)
clk[vpu_axi_sel] = imx_clk_mux("vpu_axi_sel", base + 0x18, 14, 2, vpu_axi_sels, ARRAY_SIZE(vpu_axi_sels));
clk[cko1_sel] = imx_clk_mux("cko1_sel", base + 0x60, 0, 4, cko1_sels, ARRAY_SIZE(cko1_sels));
clk[cko2_sel] = imx_clk_mux("cko2_sel", base + 0x60, 16, 5, cko2_sels, ARRAY_SIZE(cko2_sels));
+ clk[cko] = imx_clk_mux("cko", base + 0x60, 8, 1, cko_sels, ARRAY_SIZE(cko_sels));
/* name reg shift width busy: reg, shift parent_names num_parents */
clk[periph] = imx_clk_busy_mux("periph", base + 0x14, 25, 1, base + 0x48, 5, periph_sels, ARRAY_SIZE(periph_sels));
--
1.7.9.5
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH 4/4] ARM: imx6q: remove board specific CLKO setup
2013-07-18 7:31 [PATCH 0/4] ARM: imx6q: clean up board specific CLKO setup Shawn Guo
` (2 preceding siblings ...)
2013-07-18 7:31 ` [PATCH 3/4] ARM: imx6q: add the missing cko output selection Shawn Guo
@ 2013-07-18 7:31 ` Shawn Guo
2013-07-18 8:36 ` Sascha Hauer
3 siblings, 1 reply; 7+ messages in thread
From: Shawn Guo @ 2013-07-18 7:31 UTC (permalink / raw)
To: linux-arm-kernel
The CLKO is widely used by imx6q board designs to clock audio codec.
Since most codecs accept 24 MHz frequency, let's initially set up CLKO
with OSC24M (cko <-- cko2 <-- osc). Then those board specific CLKO
setup for audio codec can be removed.
The board dts files also need an update on cko reference in codec node.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
---
arch/arm/boot/dts/imx6q-sabrelite.dts | 2 +-
arch/arm/boot/dts/imx6qdl-sabresd.dtsi | 2 +-
arch/arm/boot/dts/imx6qdl-wandboard.dtsi | 2 +-
arch/arm/mach-imx/clk-imx6q.c | 11 +++++
arch/arm/mach-imx/mach-imx6q.c | 69 ------------------------------
5 files changed, 14 insertions(+), 72 deletions(-)
diff --git a/arch/arm/boot/dts/imx6q-sabrelite.dts b/arch/arm/boot/dts/imx6q-sabrelite.dts
index e0f4cd0..3530280 100644
--- a/arch/arm/boot/dts/imx6q-sabrelite.dts
+++ b/arch/arm/boot/dts/imx6q-sabrelite.dts
@@ -167,7 +167,7 @@
codec: sgtl5000 at 0a {
compatible = "fsl,sgtl5000";
reg = <0x0a>;
- clocks = <&clks 169>;
+ clocks = <&clks 201>;
VDDA-supply = <®_2p5v>;
VDDIO-supply = <®_3p3v>;
};
diff --git a/arch/arm/boot/dts/imx6qdl-sabresd.dtsi b/arch/arm/boot/dts/imx6qdl-sabresd.dtsi
index 166b9ae..75b36b2 100644
--- a/arch/arm/boot/dts/imx6qdl-sabresd.dtsi
+++ b/arch/arm/boot/dts/imx6qdl-sabresd.dtsi
@@ -109,7 +109,7 @@
codec: wm8962 at 1a {
compatible = "wlf,wm8962";
reg = <0x1a>;
- clocks = <&clks 169>;
+ clocks = <&clks 201>;
DCVDD-supply = <®_audio>;
DBVDD-supply = <®_audio>;
AVDD-supply = <®_audio>;
diff --git a/arch/arm/boot/dts/imx6qdl-wandboard.dtsi b/arch/arm/boot/dts/imx6qdl-wandboard.dtsi
index 7a46f64..77188cb 100644
--- a/arch/arm/boot/dts/imx6qdl-wandboard.dtsi
+++ b/arch/arm/boot/dts/imx6qdl-wandboard.dtsi
@@ -60,7 +60,7 @@
codec: sgtl5000 at 0a {
compatible = "fsl,sgtl5000";
reg = <0x0a>;
- clocks = <&clks 169>;
+ clocks = <&clks 201>;
VDDA-supply = <®_2p5v>;
VDDIO-supply = <®_3p3v>;
};
diff --git a/arch/arm/mach-imx/clk-imx6q.c b/arch/arm/mach-imx/clk-imx6q.c
index ed19b33..97f2702 100644
--- a/arch/arm/mach-imx/clk-imx6q.c
+++ b/arch/arm/mach-imx/clk-imx6q.c
@@ -288,6 +288,7 @@ static void __init imx6q_clocks_init(struct device_node *ccm_node)
struct device_node *np;
void __iomem *base;
int i, irq;
+ int ret;
clk[dummy] = imx_clk_fixed("dummy", 0);
clk[ckil] = imx_obtain_fixed_clock("ckil", 0);
@@ -591,6 +592,16 @@ static void __init imx6q_clocks_init(struct device_node *ccm_node)
clk_prepare_enable(clk[usbphy2_gate]);
}
+ /*
+ * Let's initially set up CLKO with OSC24M, since this configuration
+ * is widely used by imx6q board designs to clock audio codec.
+ */
+ ret = clk_set_parent(clk[cko2_sel], clk[osc]);
+ if (!ret)
+ ret = clk_set_parent(clk[cko], clk[cko2]);
+ if (ret)
+ pr_warn("failed to set up CLKO: %d\n", ret);
+
/* Set initial power mode */
imx6q_set_lpm(WAIT_CLOCKED);
diff --git a/arch/arm/mach-imx/mach-imx6q.c b/arch/arm/mach-imx/mach-imx6q.c
index 9f06cc8..2460d49 100644
--- a/arch/arm/mach-imx/mach-imx6q.c
+++ b/arch/arm/mach-imx/mach-imx6q.c
@@ -159,30 +159,6 @@ static int ar8031_phy_fixup(struct phy_device *dev)
return 0;
}
-static void __init imx6q_sabrelite_cko1_setup(void)
-{
- struct clk *cko1_sel, *ahb, *cko1;
- unsigned long rate;
-
- cko1_sel = clk_get_sys(NULL, "cko1_sel");
- ahb = clk_get_sys(NULL, "ahb");
- cko1 = clk_get_sys(NULL, "cko1");
- if (IS_ERR(cko1_sel) || IS_ERR(ahb) || IS_ERR(cko1)) {
- pr_err("cko1 setup failed!\n");
- goto put_clk;
- }
- clk_set_parent(cko1_sel, ahb);
- rate = clk_round_rate(cko1, 16000000);
- clk_set_rate(cko1, rate);
-put_clk:
- if (!IS_ERR(cko1_sel))
- clk_put(cko1_sel);
- if (!IS_ERR(ahb))
- clk_put(ahb);
- if (!IS_ERR(cko1))
- clk_put(cko1);
-}
-
#define PHY_ID_AR8031 0x004dd074
static void __init imx6q_enet_phy_init(void)
@@ -197,45 +173,6 @@ static void __init imx6q_enet_phy_init(void)
}
}
-static void __init imx6q_sabresd_cko1_setup(void)
-{
- struct clk *cko1_sel, *pll4, *pll4_post, *cko1;
- unsigned long rate;
-
- cko1_sel = clk_get_sys(NULL, "cko1_sel");
- pll4 = clk_get_sys(NULL, "pll4_audio");
- pll4_post = clk_get_sys(NULL, "pll4_post_div");
- cko1 = clk_get_sys(NULL, "cko1");
- if (IS_ERR(cko1_sel) || IS_ERR(pll4)
- || IS_ERR(pll4_post) || IS_ERR(cko1)) {
- pr_err("cko1 setup failed!\n");
- goto put_clk;
- }
- /*
- * Setting pll4 at 768MHz (24MHz * 32)
- * So its child clock can get 24MHz easily
- */
- clk_set_rate(pll4, 768000000);
-
- clk_set_parent(cko1_sel, pll4_post);
- rate = clk_round_rate(cko1, 24000000);
- clk_set_rate(cko1, rate);
-put_clk:
- if (!IS_ERR(cko1_sel))
- clk_put(cko1_sel);
- if (!IS_ERR(pll4_post))
- clk_put(pll4_post);
- if (!IS_ERR(pll4))
- clk_put(pll4);
- if (!IS_ERR(cko1))
- clk_put(cko1);
-}
-
-static void __init imx6q_sabresd_init(void)
-{
- imx6q_sabresd_cko1_setup();
-}
-
static void __init imx6q_1588_init(void)
{
struct regmap *gpr;
@@ -256,12 +193,6 @@ static void __init imx6q_usb_init(void)
static void __init imx6q_init_machine(void)
{
- if (of_machine_is_compatible("fsl,imx6q-sabrelite"))
- imx6q_sabrelite_cko1_setup();
- else if (of_machine_is_compatible("fsl,imx6q-sabresd") ||
- of_machine_is_compatible("fsl,imx6dl-sabresd"))
- imx6q_sabresd_init();
-
imx6q_enet_phy_init();
of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
--
1.7.9.5
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH 4/4] ARM: imx6q: remove board specific CLKO setup
2013-07-18 7:31 ` [PATCH 4/4] ARM: imx6q: remove board specific CLKO setup Shawn Guo
@ 2013-07-18 8:36 ` Sascha Hauer
2013-07-18 11:55 ` Shawn Guo
0 siblings, 1 reply; 7+ messages in thread
From: Sascha Hauer @ 2013-07-18 8:36 UTC (permalink / raw)
To: linux-arm-kernel
On Thu, Jul 18, 2013 at 03:31:10PM +0800, Shawn Guo wrote:
> The CLKO is widely used by imx6q board designs to clock audio codec.
> Since most codecs accept 24 MHz frequency, let's initially set up CLKO
> with OSC24M (cko <-- cko2 <-- osc). Then those board specific CLKO
> setup for audio codec can be removed.
>
> The board dts files also need an update on cko reference in codec node.
>
> + /*
> + * Let's initially set up CLKO with OSC24M, since this configuration
> + * is widely used by imx6q board designs to clock audio codec.
> + */
> + ret = clk_set_parent(clk[cko2_sel], clk[osc]);
> + if (!ret)
> + ret = clk_set_parent(clk[cko], clk[cko2]);
> + if (ret)
> + pr_warn("failed to set up CLKO: %d\n", ret);
I don't really like that the clock setup code fiddles with clocks it has
no knowledge about just because it happens to be correct for several
boards.
I currently have no example where this bites me, so I think I can live
with it for now. I just wonder what I should do when this clock is used
for something vital to the system (clocking an FPGA for example?).
Sascha
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^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH 4/4] ARM: imx6q: remove board specific CLKO setup
2013-07-18 8:36 ` Sascha Hauer
@ 2013-07-18 11:55 ` Shawn Guo
0 siblings, 0 replies; 7+ messages in thread
From: Shawn Guo @ 2013-07-18 11:55 UTC (permalink / raw)
To: linux-arm-kernel
On Thu, Jul 18, 2013 at 10:36:03AM +0200, Sascha Hauer wrote:
> On Thu, Jul 18, 2013 at 03:31:10PM +0800, Shawn Guo wrote:
> > The CLKO is widely used by imx6q board designs to clock audio codec.
> > Since most codecs accept 24 MHz frequency, let's initially set up CLKO
> > with OSC24M (cko <-- cko2 <-- osc). Then those board specific CLKO
> > setup for audio codec can be removed.
> >
> > The board dts files also need an update on cko reference in codec node.
> >
> > + /*
> > + * Let's initially set up CLKO with OSC24M, since this configuration
> > + * is widely used by imx6q board designs to clock audio codec.
> > + */
> > + ret = clk_set_parent(clk[cko2_sel], clk[osc]);
> > + if (!ret)
> > + ret = clk_set_parent(clk[cko], clk[cko2]);
> > + if (ret)
> > + pr_warn("failed to set up CLKO: %d\n", ret);
>
>
> I don't really like that the clock setup code fiddles with clocks it has
> no knowledge about just because it happens to be correct for several
> boards.
I have to admit it's not the best way to handle it, and I can understand
your concern. What I like about it is we can remove those board
specific hooks from mach-imx6q.c at least for now.
>
> I currently have no example where this bites me, so I think I can live
> with it for now. I just wonder what I should do when this clock is used
> for something vital to the system (clocking an FPGA for example?).
Go back to set up CLKO in mach-imx6q.c with board specific hook for the
system?
I think I chose to change the default CLKO setup for audio use case, as
all the users we've seen so far is audio codec. I can still have this
setup done in mach-imx6q.c with of_machine_is_compatible() check on all
those board. But that also means we need to register lookups for those
CLKO clocks and call clk_get_sys() to get them.
Shawn
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2013-07-18 11:55 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2013-07-18 7:31 [PATCH 0/4] ARM: imx6q: clean up board specific CLKO setup Shawn Guo
2013-07-18 7:31 ` [PATCH 1/4] ARM: imx6q: add spdif gate clock Shawn Guo
2013-07-18 7:31 ` [PATCH 2/4] ARM: imx6q: add cko2 clocks Shawn Guo
2013-07-18 7:31 ` [PATCH 3/4] ARM: imx6q: add the missing cko output selection Shawn Guo
2013-07-18 7:31 ` [PATCH 4/4] ARM: imx6q: remove board specific CLKO setup Shawn Guo
2013-07-18 8:36 ` Sascha Hauer
2013-07-18 11:55 ` Shawn Guo
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