* [RESEND PATCH 1/2] ARM: dts: am4372: Add "ti,am437x-ocp2scp" as compatible string for OCP2SCP @ 2015-03-17 11:24 Kishon Vijay Abraham I 2015-03-17 11:24 ` [RESEND PATCH 2/2] bus: ocp2scp: SYNC2 value should be changed to 0x6 Kishon Vijay Abraham I 0 siblings, 1 reply; 3+ messages in thread From: Kishon Vijay Abraham I @ 2015-03-17 11:24 UTC (permalink / raw) To: linux-kernel, tony, gregkh Cc: linux-arm-kernel, linux-doc, devicetree, linux-omap, nsekhar, kishon, nm, praneeth Added a new compatible string "ti,am437x-ocp2scp" for OCP2SCP module. This is needed since except for the OCP2SCP used in AM437x, SYNC2 value in OCP2SCP TIMING should be changed whereas the default value is sufficient in AM437x. Cc: Tony Lindgren <tony@atomide.com> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> --- .../devicetree/bindings/bus/omap-ocp2scp.txt | 3 ++- arch/arm/boot/dts/am4372.dtsi | 4 ++-- 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/Documentation/devicetree/bindings/bus/omap-ocp2scp.txt b/Documentation/devicetree/bindings/bus/omap-ocp2scp.txt index 63dd805..18729f6 100644 --- a/Documentation/devicetree/bindings/bus/omap-ocp2scp.txt +++ b/Documentation/devicetree/bindings/bus/omap-ocp2scp.txt @@ -1,7 +1,8 @@ * OMAP OCP2SCP - ocp interface to scp interface properties: -- compatible : Should be "ti,omap-ocp2scp" +- compatible : Should be "ti,am437x-ocp2scp" for AM437x processor + Should be "ti,omap-ocp2scp" for all others - reg : Address and length of the register set for the device - #address-cells, #size-cells : Must be present if the device has sub-nodes - ranges : the child address space are mapped 1:1 onto the parent address space diff --git a/arch/arm/boot/dts/am4372.dtsi b/arch/arm/boot/dts/am4372.dtsi index 1943fc3..286e317 100644 --- a/arch/arm/boot/dts/am4372.dtsi +++ b/arch/arm/boot/dts/am4372.dtsi @@ -787,7 +787,7 @@ }; ocp2scp0: ocp2scp@483a8000 { - compatible = "ti,omap-ocp2scp"; + compatible = "ti,am437x-ocp2scp", "ti,omap-ocp2scp"; #address-cells = <1>; #size-cells = <1>; ranges; @@ -806,7 +806,7 @@ }; ocp2scp1: ocp2scp@483e8000 { - compatible = "ti,omap-ocp2scp"; + compatible = "ti,am437x-ocp2scp", "ti,omap-ocp2scp"; #address-cells = <1>; #size-cells = <1>; ranges; -- 1.7.9.5 ^ permalink raw reply related [flat|nested] 3+ messages in thread
* [RESEND PATCH 2/2] bus: ocp2scp: SYNC2 value should be changed to 0x6 2015-03-17 11:24 [RESEND PATCH 1/2] ARM: dts: am4372: Add "ti,am437x-ocp2scp" as compatible string for OCP2SCP Kishon Vijay Abraham I @ 2015-03-17 11:24 ` Kishon Vijay Abraham I 2015-03-26 17:50 ` Tony Lindgren 0 siblings, 1 reply; 3+ messages in thread From: Kishon Vijay Abraham I @ 2015-03-17 11:24 UTC (permalink / raw) To: linux-kernel, tony, gregkh Cc: linux-arm-kernel, linux-doc, devicetree, linux-omap, nsekhar, kishon, nm, praneeth, Arnd Bergmann As per the TRMs of AM572x, OMAP4430, OMAP4460, OMAP543x, the value of SYNC2 must be set to 0x6 in order to ensure correct operation. So modified the SYNC2 value of OCP2SCP TIMING register to 0x6 in all the platforms that use OCP2SCP driver except AM437x. Also introduced a new compatible property since we don't want to modify the OCP2SCP TIMING register for AM437x. The sections in TRM where the above caution can be found is mentioned below. AM572x TRM SPRUHZ6 (http://www.ti.com/lit/ug/spruhz6/spruhz6.pdf) under section 26.3.2.2, table 26-26. OMAP4430 TRM SWPU231AP (http://www.ti.com/lit/ug/swpu231ap/swpu231ap.pdf) under section 23.12.6.2.2 , Table 23-1213. OMAP4460 TRM SWPU235AB (http://www.ti.com/lit/ug/swpu235ab/swpu235ab.pdf) under section 23.12.6.2.2, Table 23-1213. OMAP543x TRM SWPU249 (http://www.ti.com/lit/pdf/swpu249) under section 27.3.2.2, Table 27-27. Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Praneeth Bajjuri <praneeth@ti.com> --- drivers/bus/omap-ocp2scp.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/drivers/bus/omap-ocp2scp.c b/drivers/bus/omap-ocp2scp.c index 723ec06..9f18569 100644 --- a/drivers/bus/omap-ocp2scp.c +++ b/drivers/bus/omap-ocp2scp.c @@ -16,6 +16,7 @@ * */ +#include <linux/io.h> #include <linux/module.h> #include <linux/platform_device.h> #include <linux/err.h> @@ -23,6 +24,9 @@ #include <linux/of.h> #include <linux/of_platform.h> +#define OCP2SCP_TIMING 0x18 +#define SYNC2_MASK 0xf + static int ocp2scp_remove_devices(struct device *dev, void *c) { struct platform_device *pdev = to_platform_device(dev); @@ -35,6 +39,9 @@ static int ocp2scp_remove_devices(struct device *dev, void *c) static int omap_ocp2scp_probe(struct platform_device *pdev) { int ret; + u32 reg; + void __iomem *regs; + struct resource *res; struct device_node *np = pdev->dev.of_node; if (np) { @@ -47,6 +54,32 @@ static int omap_ocp2scp_probe(struct platform_device *pdev) } pm_runtime_enable(&pdev->dev); + /* + * As per AM572x TRM: http://www.ti.com/lit/ug/spruhz6/spruhz6.pdf + * under section 26.3.2.2, table 26-26 OCP2SCP TIMING Caution; + * As per OMAP4430 TRM: http://www.ti.com/lit/ug/swpu231ap/swpu231ap.pdf + * under section 23.12.6.2.2 , Table 23-1213 OCP2SCP TIMING Caution; + * As per OMAP4460 TRM: http://www.ti.com/lit/ug/swpu235ab/swpu235ab.pdf + * under section 23.12.6.2.2, Table 23-1213 OCP2SCP TIMING Caution; + * As per OMAP543x TRM http://www.ti.com/lit/pdf/swpu249 + * under section 27.3.2.2, Table 27-27 OCP2SCP TIMING Caution; + * + * Read path of OCP2SCP is not working properly due to low reset value + * of SYNC2 parameter in OCP2SCP. Suggested reset value is 0x6 or more. + */ + if (!of_device_is_compatible(np, "ti,am437x-ocp2scp")) { + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + regs = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(regs)) + goto err0; + + pm_runtime_get_sync(&pdev->dev); + reg = readl_relaxed(regs + OCP2SCP_TIMING); + reg &= ~(SYNC2_MASK); + reg |= 0x6; + writel_relaxed(reg, regs + OCP2SCP_TIMING); + pm_runtime_put_sync(&pdev->dev); + } return 0; @@ -67,6 +100,7 @@ static int omap_ocp2scp_remove(struct platform_device *pdev) #ifdef CONFIG_OF static const struct of_device_id omap_ocp2scp_id_table[] = { { .compatible = "ti,omap-ocp2scp" }, + { .compatible = "ti,am437x-ocp2scp" }, {} }; MODULE_DEVICE_TABLE(of, omap_ocp2scp_id_table); -- 1.7.9.5 ^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [RESEND PATCH 2/2] bus: ocp2scp: SYNC2 value should be changed to 0x6 2015-03-17 11:24 ` [RESEND PATCH 2/2] bus: ocp2scp: SYNC2 value should be changed to 0x6 Kishon Vijay Abraham I @ 2015-03-26 17:50 ` Tony Lindgren 0 siblings, 0 replies; 3+ messages in thread From: Tony Lindgren @ 2015-03-26 17:50 UTC (permalink / raw) To: Kishon Vijay Abraham I Cc: linux-kernel, gregkh, linux-arm-kernel, linux-doc, devicetree, linux-omap, nsekhar, nm, praneeth, Arnd Bergmann * Kishon Vijay Abraham I <kishon@ti.com> [150317 04:25]: > As per the TRMs of AM572x, OMAP4430, OMAP4460, OMAP543x, the value of > SYNC2 must be set to 0x6 in order to ensure correct operation. > > So modified the SYNC2 value of OCP2SCP TIMING register to 0x6 in all the > platforms that use OCP2SCP driver except AM437x. Also introduced a new > compatible property since we don't want to modify the OCP2SCP TIMING > register for AM437x. OK thanks I'll apply both into omap-for-v4.1/fixes-not-urgent as it seems we've gotten away with it for quite a few years now, and I don't see any specific description of what these fix. If that's not the case, please let me know. Regards, Tony ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2015-03-26 17:50 UTC | newest] Thread overview: 3+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2015-03-17 11:24 [RESEND PATCH 1/2] ARM: dts: am4372: Add "ti,am437x-ocp2scp" as compatible string for OCP2SCP Kishon Vijay Abraham I 2015-03-17 11:24 ` [RESEND PATCH 2/2] bus: ocp2scp: SYNC2 value should be changed to 0x6 Kishon Vijay Abraham I 2015-03-26 17:50 ` Tony Lindgren
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