diff options
Diffstat (limited to 'drivers/bus')
| -rw-r--r-- | drivers/bus/omap-ocp2scp.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/drivers/bus/omap-ocp2scp.c b/drivers/bus/omap-ocp2scp.c index 723ec06ad2c8..9f1856948758 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); |