Hello everyone, The Samsung SoCs from Exynos family are enhanced with a bunch of switches dedicated for IP blocks. Those switches are called PHYs in Exynos specification. They are usually controlled by a single bit in a single one-word-long register. A IP driver has to control such a switch in an abstract manner. Therefore, such 'enablers' were implemented as clocks in older versions of Linux kernel. With the dawn of PHY subsystems, PHYs become a natural way of exporting the 'enabler' functionality to drivers. However, there is an unexpected consequence. Some of those 1-bit PHYs were implemented as separate drivers. This means that one has to create a struct device, struct phy, its phy provider and 100-150 lines of driver code to basically set one bit. The DP phy driver is a good example: https://lkml.org/lkml/2013/7/18/53 And simple-phy RFC (shares only driver code but not other resources): https://lkml.org/lkml/2013/10/21/313 To avoid waste of resources I propose to create all such 1-bit phys from Exynos SoC using a single device, driver and phy provider. This patchset contains a proposed solution. All comment are welcome. Hopefully in future the functionality introduced by this patch may be merged into a larger Power Management Unit (PMU) gluer driver. On Samsusng SoC , the PMU part contains a number of register barely linked to power management (like clock gating, clock dividers, CPU resetting, etc.). It may be tempting to create a hybrid driver that export clocks/phys/etc that are controlled by PMU unit. Regards, Tomasz Stanislawski Tomasz Stanislawski (1): phy: Add exynos-phy driver drivers/phy/Kconfig | 5 ++ drivers/phy/Makefile | 1 + drivers/phy/exynos-phy.c | 152 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 158 insertions(+) create mode 100644 drivers/phy/exynos-phy.c -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
