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authorGerhard Sittig <gsi@denx.de>2013-11-30 23:51:24 +0100
committerAnatolij Gustschin <agust@denx.de>2014-01-12 18:53:03 +0100
commit6d8cdb68249d2a5d2504a7bc79a8cfb517e07020 (patch)
tree52946f166cd29adbd3665892bc413ab9fe6ae319 /include/linux/clk-provider.h
parentf87ccd2edcdbe86ffb7cf7286e1c7aa84d5e5af9 (diff)
clk: mpc512x: introduce COMMON_CLK for MPC512x (disabled)
this change implements a clock driver for the MPC512x PowerPC platform which follows the COMMON_CLK approach and uses common clock drivers shared with other platforms this driver implements the publicly announced set of clocks (those listed in the dt-bindings header file), as well as generates additional 'struct clk' items where the SoC hardware cannot easily get mapped to the common primitives (shared code) of the clock API, or requires "intermediate clock nodes" to represent clocks that have both gates and dividers the previous PPC_CLOCK implementation is kept in place and remains active for the moment, the newly introduced CCF clock driver will receive additional support for backwards compatibility in a subsequent patch before it gets enabled and will replace the PPC_CLOCK approach some of the clock items get pre-enabled in the clock driver to not have them automatically disabled by the underlying clock subsystem because of their being unused -- this approach is desirable because - some of the clocks are useful to have for diagnostics and information despite their not getting claimed by any drivers (CPU, internal and external RAM, internal busses, boot media) - some of the clocks aren't claimed by their peripheral drivers yet, either because of missing driver support or because device tree specs aren't available yet (but the workarounds will get removed as the drivers get adjusted and the device tree provides the clock specs) clkdev registration provides "alias names" for few clock items - to not break those peripheral drivers which encode their component index into the name that is used for clock lookup (UART, SPI, USB) - to not break those drivers which use names for the clock lookup which were encoded in the previous PPC_CLOCK implementation (NFC, VIU, CAN) this workaround will get removed as these drivers get adjusted after device tree based clock lookup has become available the COMMON_CLK implementation copes with device trees which lack an oscillator node (backwards compat), the REF clock is then derived from the IPS bus frequency and multiplier values fetched from hardware Cc: Mike Turquette <mturquette@linaro.org> Cc: Anatolij Gustschin <agust@denx.de> Cc: linux-arm-kernel@lists.infradead.org Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Gerhard Sittig <gsi@denx.de> Signed-off-by: Anatolij Gustschin <agust@denx.de>
Diffstat (limited to 'include/linux/clk-provider.h')
-rw-r--r--include/linux/clk-provider.h16
1 files changed, 16 insertions, 0 deletions
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 7e59253b8603..534dc618f2d7 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -512,6 +512,20 @@ static inline const char *of_clk_get_parent_name(struct device_node *np,
* for improved portability across platforms
*/
+#if IS_ENABLED(CONFIG_PPC)
+
+static inline u32 clk_readl(u32 __iomem *reg)
+{
+ return ioread32be(reg);
+}
+
+static inline void clk_writel(u32 val, u32 __iomem *reg)
+{
+ iowrite32be(val, reg);
+}
+
+#else /* platform dependent I/O accessors */
+
static inline u32 clk_readl(u32 __iomem *reg)
{
return readl(reg);
@@ -522,5 +536,7 @@ static inline void clk_writel(u32 val, u32 __iomem *reg)
writel(val, reg);
}
+#endif /* platform dependent I/O accessors */
+
#endif /* CONFIG_COMMON_CLK */
#endif /* CLK_PROVIDER_H */