[alsa-devel] [PATCH v5] ASoC: fsl_sai: Add clock controls for SAI
The SAI mainly has the following clocks: bus clock control and configure registers and to generate synchronous interrupts and DMA requests.
mclk1, mclk2, mclk3 to generate the bit clock when the receiver or transmitter is configured for an internally generated bit clock.
So this patch adds these clocks and their clock controls to the driver, meanwhile, corrects the existing DTS accordingly so those platforms can benifit from the further feature with different clock sources.
[ To concern the old DTB cases, I've added a bit of extra code to make the driver compatible with them. And by marking clock NULL if failed to get, the clk_prepare() or clk_get_rate() would easily return 0 so no further path should be broken. -- by Nicolin ]
Signed-off-by: Nicolin Chen Guangyu.Chen@freescale.com Acked-by: Xiubo Li Li.Xiubo@freescale.com Acked-by: Shawn Guo shawn.guo@linaro.org ---
Changelog v5: * Dropped mclk preparing and enabling since we are not using them currecntly. * Made the change compatible to the old DTB. * Added returned error value print. v4: * Merged into single patch. * Fixed bus clock ID on vf610. v3: * Use int type for ret instead of u32. * Added Acked-by and Tested-by from Xiubo Li. v2: * Appended two extra mclks to the driver since SAI actually has three. * Renamed clock name to 'bus' and 'mclk' according to the reference manual.
.../devicetree/bindings/sound/fsl-sai.txt | 9 +++-- arch/arm/boot/dts/vf610.dtsi | 6 ++-- sound/soc/fsl/fsl_sai.c | 38 ++++++++++++++++++++-- sound/soc/fsl/fsl_sai.h | 4 +++ 4 files changed, 50 insertions(+), 7 deletions(-)
diff --git a/Documentation/devicetree/bindings/sound/fsl-sai.txt b/Documentation/devicetree/bindings/sound/fsl-sai.txt index 35c09fe..0f4e238 100644 --- a/Documentation/devicetree/bindings/sound/fsl-sai.txt +++ b/Documentation/devicetree/bindings/sound/fsl-sai.txt @@ -10,7 +10,8 @@ Required properties: - compatible: Compatible list, contains "fsl,vf610-sai" or "fsl,imx6sx-sai". - reg: Offset and length of the register set for the device. - clocks: Must contain an entry for each entry in clock-names. -- clock-names : Must include the "sai" entry. +- clock-names : Must include the "bus" for register access and "mclk1" "mclk2" + "mclk3" for bit clock and frame clock providing. - dmas : Generic dma devicetree binding as described in Documentation/devicetree/bindings/dma/dma.txt. - dma-names : Two dmas have to be defined, "tx" and "rx". @@ -30,8 +31,10 @@ sai2: sai@40031000 { reg = <0x40031000 0x1000>; pinctrl-names = "default"; pinctrl-0 = <&pinctrl_sai2_1>; - clocks = <&clks VF610_CLK_SAI2>; - clock-names = "sai"; + clocks = <&clks VF610_CLK_PLATFORM_BUS>, + <&clks VF610_CLK_SAI2>, + <&clks 0>, <&clks 0>; + clock-names = "bus", "mclk1", "mclk2", "mclk3"; dma-names = "tx", "rx"; dmas = <&edma0 0 VF610_EDMA_MUXID0_SAI2_TX>, <&edma0 0 VF610_EDMA_MUXID0_SAI2_RX>; diff --git a/arch/arm/boot/dts/vf610.dtsi b/arch/arm/boot/dts/vf610.dtsi index d31ce1b..4c3cd59 100644 --- a/arch/arm/boot/dts/vf610.dtsi +++ b/arch/arm/boot/dts/vf610.dtsi @@ -139,8 +139,10 @@ compatible = "fsl,vf610-sai"; reg = <0x40031000 0x1000>; interrupts = <0 86 0x04>; - clocks = <&clks VF610_CLK_SAI2>; - clock-names = "sai"; + clocks = <&clks VF610_CLK_PLATFORM_BUS>, + <&clks VF610_CLK_SAI2>, + <&clks 0>, <&clks 0>; + clock-names = "bus", "mclk1", "mclk2", "mclk3"; status = "disabled"; };
diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c index db9f75e..5fff2e1 100644 --- a/sound/soc/fsl/fsl_sai.c +++ b/sound/soc/fsl/fsl_sai.c @@ -401,7 +401,15 @@ static int fsl_sai_startup(struct snd_pcm_substream *substream, struct snd_soc_dai *cpu_dai) { struct fsl_sai *sai = snd_soc_dai_get_drvdata(cpu_dai); + struct device *dev = &sai->pdev->dev; u32 reg; + int ret; + + ret = clk_prepare_enable(sai->bus_clk); + if (ret) { + dev_err(dev, "failed to enable bus clock: %d\n", ret); + return ret; + }
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) reg = FSL_SAI_TCR3; @@ -427,6 +435,8 @@ static void fsl_sai_shutdown(struct snd_pcm_substream *substream,
regmap_update_bits(sai->regmap, reg, FSL_SAI_CR3_TRCE, ~FSL_SAI_CR3_TRCE); + + clk_disable_unprepare(sai->bus_clk); }
static const struct snd_soc_dai_ops fsl_sai_pcm_dai_ops = { @@ -559,7 +569,8 @@ static int fsl_sai_probe(struct platform_device *pdev) struct fsl_sai *sai; struct resource *res; void __iomem *base; - int irq, ret; + char tmp[8]; + int irq, ret, i;
sai = devm_kzalloc(&pdev->dev, sizeof(*sai), GFP_KERNEL); if (!sai) @@ -582,12 +593,35 @@ static int fsl_sai_probe(struct platform_device *pdev) return PTR_ERR(base);
sai->regmap = devm_regmap_init_mmio_clk(&pdev->dev, - "sai", base, &fsl_sai_regmap_config); + "bus", base, &fsl_sai_regmap_config); + + /* Compatible with old DTB cases */ + if (IS_ERR(sai->regmap)) + sai->regmap = devm_regmap_init_mmio_clk(&pdev->dev, + "sai", base, &fsl_sai_regmap_config); if (IS_ERR(sai->regmap)) { dev_err(&pdev->dev, "regmap init failed\n"); return PTR_ERR(sai->regmap); }
+ /* No error out for old DTB cases but only mark the clock NULL */ + sai->bus_clk = devm_clk_get(&pdev->dev, "bus"); + if (IS_ERR(sai->bus_clk)) { + dev_err(&pdev->dev, "failed to get bus clock: %ld\n", + PTR_ERR(sai->bus_clk)); + sai->bus_clk = NULL; + } + + for (i = 0; i < FSL_SAI_MCLK_MAX; i++) { + sprintf(tmp, "mclk%d", i + 1); + sai->mclk_clk[i] = devm_clk_get(&pdev->dev, tmp); + if (IS_ERR(sai->mclk_clk[i])) { + dev_err(&pdev->dev, "failed to get mclk%d clock: %ld\n", + i + 1, PTR_ERR(sai->mclk_clk[i])); + sai->mclk_clk[i] = NULL; + } + } + irq = platform_get_irq(pdev, 0); if (irq < 0) { dev_err(&pdev->dev, "no irq for node %s\n", np->full_name); diff --git a/sound/soc/fsl/fsl_sai.h b/sound/soc/fsl/fsl_sai.h index 677670d..0e6c9f5 100644 --- a/sound/soc/fsl/fsl_sai.h +++ b/sound/soc/fsl/fsl_sai.h @@ -119,6 +119,8 @@ #define FSL_SAI_CLK_MAST2 2 #define FSL_SAI_CLK_MAST3 3
+#define FSL_SAI_MCLK_MAX 3 + /* SAI data transfer numbers per DMA request */ #define FSL_SAI_MAXBURST_TX 6 #define FSL_SAI_MAXBURST_RX 6 @@ -126,6 +128,8 @@ struct fsl_sai { struct platform_device *pdev; struct regmap *regmap; + struct clk *bus_clk; + struct clk *mclk_clk[FSL_SAI_MCLK_MAX];
bool big_endian_regs; bool big_endian_data;
On Thu, Apr 10, 2014 at 07:23:12PM +0800, Nicolin Chen wrote:
The SAI mainly has the following clocks: bus clock control and configure registers and to generate synchronous interrupts and DMA requests.
mclk1, mclk2, mclk3 to generate the bit clock when the receiver or transmitter is configured for an internally generated bit clock.
So this patch adds these clocks and their clock controls to the driver, meanwhile, corrects the existing DTS accordingly so those platforms can benifit from the further feature with different clock sources.
[ To concern the old DTB cases, I've added a bit of extra code to make the driver compatible with them. And by marking clock NULL if failed to get, the clk_prepare() or clk_get_rate() would easily return 0 so no further path should be broken. -- by Nicolin ]
In this case, the arch/arm/boot/dts/vf610.dtsi can just go via IMX tree, since nothing should be broken on sound tree even without dts change?
Shawn
Signed-off-by: Nicolin Chen Guangyu.Chen@freescale.com Acked-by: Xiubo Li Li.Xiubo@freescale.com Acked-by: Shawn Guo shawn.guo@linaro.org
Changelog v5:
- Dropped mclk preparing and enabling since we are not using them currecntly.
- Made the change compatible to the old DTB.
- Added returned error value print.
v4:
- Merged into single patch.
- Fixed bus clock ID on vf610.
v3:
- Use int type for ret instead of u32.
- Added Acked-by and Tested-by from Xiubo Li.
v2:
- Appended two extra mclks to the driver since SAI actually has three.
- Renamed clock name to 'bus' and 'mclk' according to the reference manual.
.../devicetree/bindings/sound/fsl-sai.txt | 9 +++-- arch/arm/boot/dts/vf610.dtsi | 6 ++-- sound/soc/fsl/fsl_sai.c | 38 ++++++++++++++++++++-- sound/soc/fsl/fsl_sai.h | 4 +++ 4 files changed, 50 insertions(+), 7 deletions(-)
diff --git a/Documentation/devicetree/bindings/sound/fsl-sai.txt b/Documentation/devicetree/bindings/sound/fsl-sai.txt index 35c09fe..0f4e238 100644 --- a/Documentation/devicetree/bindings/sound/fsl-sai.txt +++ b/Documentation/devicetree/bindings/sound/fsl-sai.txt @@ -10,7 +10,8 @@ Required properties:
- compatible: Compatible list, contains "fsl,vf610-sai" or "fsl,imx6sx-sai".
- reg: Offset and length of the register set for the device.
- clocks: Must contain an entry for each entry in clock-names.
-- clock-names : Must include the "sai" entry. +- clock-names : Must include the "bus" for register access and "mclk1" "mclk2"
- "mclk3" for bit clock and frame clock providing.
- dmas : Generic dma devicetree binding as described in Documentation/devicetree/bindings/dma/dma.txt.
- dma-names : Two dmas have to be defined, "tx" and "rx".
@@ -30,8 +31,10 @@ sai2: sai@40031000 { reg = <0x40031000 0x1000>; pinctrl-names = "default"; pinctrl-0 = <&pinctrl_sai2_1>;
clocks = <&clks VF610_CLK_SAI2>;clock-names = "sai";
clocks = <&clks VF610_CLK_PLATFORM_BUS>,<&clks VF610_CLK_SAI2>,<&clks 0>, <&clks 0>;clock-names = "bus", "mclk1", "mclk2", "mclk3"; dma-names = "tx", "rx"; dmas = <&edma0 0 VF610_EDMA_MUXID0_SAI2_TX>, <&edma0 0 VF610_EDMA_MUXID0_SAI2_RX>;diff --git a/arch/arm/boot/dts/vf610.dtsi b/arch/arm/boot/dts/vf610.dtsi index d31ce1b..4c3cd59 100644 --- a/arch/arm/boot/dts/vf610.dtsi +++ b/arch/arm/boot/dts/vf610.dtsi @@ -139,8 +139,10 @@ compatible = "fsl,vf610-sai"; reg = <0x40031000 0x1000>; interrupts = <0 86 0x04>;
clocks = <&clks VF610_CLK_SAI2>;clock-names = "sai";
clocks = <&clks VF610_CLK_PLATFORM_BUS>,<&clks VF610_CLK_SAI2>,<&clks 0>, <&clks 0>;clock-names = "bus", "mclk1", "mclk2", "mclk3"; status = "disabled"; };diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c index db9f75e..5fff2e1 100644 --- a/sound/soc/fsl/fsl_sai.c +++ b/sound/soc/fsl/fsl_sai.c @@ -401,7 +401,15 @@ static int fsl_sai_startup(struct snd_pcm_substream *substream, struct snd_soc_dai *cpu_dai) { struct fsl_sai *sai = snd_soc_dai_get_drvdata(cpu_dai);
struct device *dev = &sai->pdev->dev; u32 reg;
int ret;
ret = clk_prepare_enable(sai->bus_clk);
if (ret) {
dev_err(dev, "failed to enable bus clock: %d\n", ret);return ret;}
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) reg = FSL_SAI_TCR3;
@@ -427,6 +435,8 @@ static void fsl_sai_shutdown(struct snd_pcm_substream *substream,
regmap_update_bits(sai->regmap, reg, FSL_SAI_CR3_TRCE, ~FSL_SAI_CR3_TRCE);
- clk_disable_unprepare(sai->bus_clk);
}
static const struct snd_soc_dai_ops fsl_sai_pcm_dai_ops = { @@ -559,7 +569,8 @@ static int fsl_sai_probe(struct platform_device *pdev) struct fsl_sai *sai; struct resource *res; void __iomem *base;
- int irq, ret;
char tmp[8];
int irq, ret, i;
sai = devm_kzalloc(&pdev->dev, sizeof(*sai), GFP_KERNEL); if (!sai)
@@ -582,12 +593,35 @@ static int fsl_sai_probe(struct platform_device *pdev) return PTR_ERR(base);
sai->regmap = devm_regmap_init_mmio_clk(&pdev->dev,
"sai", base, &fsl_sai_regmap_config);
"bus", base, &fsl_sai_regmap_config);/* Compatible with old DTB cases */
if (IS_ERR(sai->regmap))
sai->regmap = devm_regmap_init_mmio_clk(&pdev->dev,"sai", base, &fsl_sai_regmap_config);if (IS_ERR(sai->regmap)) { dev_err(&pdev->dev, "regmap init failed\n"); return PTR_ERR(sai->regmap); }
/* No error out for old DTB cases but only mark the clock NULL */
sai->bus_clk = devm_clk_get(&pdev->dev, "bus");
if (IS_ERR(sai->bus_clk)) {
dev_err(&pdev->dev, "failed to get bus clock: %ld\n",PTR_ERR(sai->bus_clk));sai->bus_clk = NULL;}
for (i = 0; i < FSL_SAI_MCLK_MAX; i++) {
sprintf(tmp, "mclk%d", i + 1);sai->mclk_clk[i] = devm_clk_get(&pdev->dev, tmp);if (IS_ERR(sai->mclk_clk[i])) {dev_err(&pdev->dev, "failed to get mclk%d clock: %ld\n",i + 1, PTR_ERR(sai->mclk_clk[i]));sai->mclk_clk[i] = NULL;}}
irq = platform_get_irq(pdev, 0); if (irq < 0) { dev_err(&pdev->dev, "no irq for node %s\n", np->full_name);
diff --git a/sound/soc/fsl/fsl_sai.h b/sound/soc/fsl/fsl_sai.h index 677670d..0e6c9f5 100644 --- a/sound/soc/fsl/fsl_sai.h +++ b/sound/soc/fsl/fsl_sai.h @@ -119,6 +119,8 @@ #define FSL_SAI_CLK_MAST2 2 #define FSL_SAI_CLK_MAST3 3
+#define FSL_SAI_MCLK_MAX 3
/* SAI data transfer numbers per DMA request */ #define FSL_SAI_MAXBURST_TX 6 #define FSL_SAI_MAXBURST_RX 6 @@ -126,6 +128,8 @@ struct fsl_sai { struct platform_device *pdev; struct regmap *regmap;
struct clk *bus_clk;
struct clk *mclk_clk[FSL_SAI_MCLK_MAX];
bool big_endian_regs; bool big_endian_data;
-- 1.8.4
On Thu, Apr 10, 2014 at 10:07:47PM +0800, Shawn Guo wrote:
On Thu, Apr 10, 2014 at 07:23:12PM +0800, Nicolin Chen wrote:
The SAI mainly has the following clocks: bus clock control and configure registers and to generate synchronous interrupts and DMA requests.
mclk1, mclk2, mclk3 to generate the bit clock when the receiver or transmitter is configured for an internally generated bit clock.
So this patch adds these clocks and their clock controls to the driver, meanwhile, corrects the existing DTS accordingly so those platforms can benifit from the further feature with different clock sources.
[ To concern the old DTB cases, I've added a bit of extra code to make the driver compatible with them. And by marking clock NULL if failed to get, the clk_prepare() or clk_get_rate() would easily return 0 so no further path should be broken. -- by Nicolin ]
In this case, the arch/arm/boot/dts/vf610.dtsi can just go via IMX tree, since nothing should be broken on sound tree even without dts change?
You are right...I'll send the v6.
Thank you, Nicolin
----
Shawn
Signed-off-by: Nicolin Chen Guangyu.Chen@freescale.com Acked-by: Xiubo Li Li.Xiubo@freescale.com Acked-by: Shawn Guo shawn.guo@linaro.org
Changelog v5:
- Dropped mclk preparing and enabling since we are not using them currecntly.
- Made the change compatible to the old DTB.
- Added returned error value print.
v4:
- Merged into single patch.
- Fixed bus clock ID on vf610.
v3:
- Use int type for ret instead of u32.
- Added Acked-by and Tested-by from Xiubo Li.
v2:
- Appended two extra mclks to the driver since SAI actually has three.
- Renamed clock name to 'bus' and 'mclk' according to the reference manual.
.../devicetree/bindings/sound/fsl-sai.txt | 9 +++-- arch/arm/boot/dts/vf610.dtsi | 6 ++-- sound/soc/fsl/fsl_sai.c | 38 ++++++++++++++++++++-- sound/soc/fsl/fsl_sai.h | 4 +++ 4 files changed, 50 insertions(+), 7 deletions(-)
diff --git a/Documentation/devicetree/bindings/sound/fsl-sai.txt b/Documentation/devicetree/bindings/sound/fsl-sai.txt index 35c09fe..0f4e238 100644 --- a/Documentation/devicetree/bindings/sound/fsl-sai.txt +++ b/Documentation/devicetree/bindings/sound/fsl-sai.txt @@ -10,7 +10,8 @@ Required properties:
- compatible: Compatible list, contains "fsl,vf610-sai" or "fsl,imx6sx-sai".
- reg: Offset and length of the register set for the device.
- clocks: Must contain an entry for each entry in clock-names.
-- clock-names : Must include the "sai" entry. +- clock-names : Must include the "bus" for register access and "mclk1" "mclk2"
- "mclk3" for bit clock and frame clock providing.
- dmas : Generic dma devicetree binding as described in Documentation/devicetree/bindings/dma/dma.txt.
- dma-names : Two dmas have to be defined, "tx" and "rx".
@@ -30,8 +31,10 @@ sai2: sai@40031000 { reg = <0x40031000 0x1000>; pinctrl-names = "default"; pinctrl-0 = <&pinctrl_sai2_1>;
clocks = <&clks VF610_CLK_SAI2>;clock-names = "sai";
clocks = <&clks VF610_CLK_PLATFORM_BUS>,<&clks VF610_CLK_SAI2>,<&clks 0>, <&clks 0>;clock-names = "bus", "mclk1", "mclk2", "mclk3"; dma-names = "tx", "rx"; dmas = <&edma0 0 VF610_EDMA_MUXID0_SAI2_TX>, <&edma0 0 VF610_EDMA_MUXID0_SAI2_RX>;diff --git a/arch/arm/boot/dts/vf610.dtsi b/arch/arm/boot/dts/vf610.dtsi index d31ce1b..4c3cd59 100644 --- a/arch/arm/boot/dts/vf610.dtsi +++ b/arch/arm/boot/dts/vf610.dtsi @@ -139,8 +139,10 @@ compatible = "fsl,vf610-sai"; reg = <0x40031000 0x1000>; interrupts = <0 86 0x04>;
clocks = <&clks VF610_CLK_SAI2>;clock-names = "sai";
clocks = <&clks VF610_CLK_PLATFORM_BUS>,<&clks VF610_CLK_SAI2>,<&clks 0>, <&clks 0>;clock-names = "bus", "mclk1", "mclk2", "mclk3"; status = "disabled"; };diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c index db9f75e..5fff2e1 100644 --- a/sound/soc/fsl/fsl_sai.c +++ b/sound/soc/fsl/fsl_sai.c @@ -401,7 +401,15 @@ static int fsl_sai_startup(struct snd_pcm_substream *substream, struct snd_soc_dai *cpu_dai) { struct fsl_sai *sai = snd_soc_dai_get_drvdata(cpu_dai);
struct device *dev = &sai->pdev->dev; u32 reg;
int ret;
ret = clk_prepare_enable(sai->bus_clk);
if (ret) {
dev_err(dev, "failed to enable bus clock: %d\n", ret);return ret;}
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) reg = FSL_SAI_TCR3;
@@ -427,6 +435,8 @@ static void fsl_sai_shutdown(struct snd_pcm_substream *substream,
regmap_update_bits(sai->regmap, reg, FSL_SAI_CR3_TRCE, ~FSL_SAI_CR3_TRCE);
- clk_disable_unprepare(sai->bus_clk);
}
static const struct snd_soc_dai_ops fsl_sai_pcm_dai_ops = { @@ -559,7 +569,8 @@ static int fsl_sai_probe(struct platform_device *pdev) struct fsl_sai *sai; struct resource *res; void __iomem *base;
- int irq, ret;
char tmp[8];
int irq, ret, i;
sai = devm_kzalloc(&pdev->dev, sizeof(*sai), GFP_KERNEL); if (!sai)
@@ -582,12 +593,35 @@ static int fsl_sai_probe(struct platform_device *pdev) return PTR_ERR(base);
sai->regmap = devm_regmap_init_mmio_clk(&pdev->dev,
"sai", base, &fsl_sai_regmap_config);
"bus", base, &fsl_sai_regmap_config);/* Compatible with old DTB cases */
if (IS_ERR(sai->regmap))
sai->regmap = devm_regmap_init_mmio_clk(&pdev->dev,"sai", base, &fsl_sai_regmap_config);if (IS_ERR(sai->regmap)) { dev_err(&pdev->dev, "regmap init failed\n"); return PTR_ERR(sai->regmap); }
/* No error out for old DTB cases but only mark the clock NULL */
sai->bus_clk = devm_clk_get(&pdev->dev, "bus");
if (IS_ERR(sai->bus_clk)) {
dev_err(&pdev->dev, "failed to get bus clock: %ld\n",PTR_ERR(sai->bus_clk));sai->bus_clk = NULL;}
for (i = 0; i < FSL_SAI_MCLK_MAX; i++) {
sprintf(tmp, "mclk%d", i + 1);sai->mclk_clk[i] = devm_clk_get(&pdev->dev, tmp);if (IS_ERR(sai->mclk_clk[i])) {dev_err(&pdev->dev, "failed to get mclk%d clock: %ld\n",i + 1, PTR_ERR(sai->mclk_clk[i]));sai->mclk_clk[i] = NULL;}}
irq = platform_get_irq(pdev, 0); if (irq < 0) { dev_err(&pdev->dev, "no irq for node %s\n", np->full_name);
diff --git a/sound/soc/fsl/fsl_sai.h b/sound/soc/fsl/fsl_sai.h index 677670d..0e6c9f5 100644 --- a/sound/soc/fsl/fsl_sai.h +++ b/sound/soc/fsl/fsl_sai.h @@ -119,6 +119,8 @@ #define FSL_SAI_CLK_MAST2 2 #define FSL_SAI_CLK_MAST3 3
+#define FSL_SAI_MCLK_MAX 3
/* SAI data transfer numbers per DMA request */ #define FSL_SAI_MAXBURST_TX 6 #define FSL_SAI_MAXBURST_RX 6 @@ -126,6 +128,8 @@ struct fsl_sai { struct platform_device *pdev; struct regmap *regmap;
struct clk *bus_clk;
struct clk *mclk_clk[FSL_SAI_MCLK_MAX];
bool big_endian_regs; bool big_endian_data;
-- 1.8.4
participants (2)
-
Nicolin Chen -
Shawn Guo