[PATCH v5 00/17] add COMMON_CLK support for PowerPC MPC512x

[PATCH v5 00/17] add COMMON_CLK support for PowerPC MPC512x

[Gerhard Sittig]

this series introduces support for the common clock framework (CCF,
COMMON_CLK Kconfig option) in the PowerPC based MPC512x platform, which
brings device tree based clock lookup as well

at subsystem maintainers:

this series was streamlined for conflict free application through the
subsystems' individual trees, and consists of the following phases
- peripheral driver cleanup (1/17) (not essential, in fact comments only
  and code which is a NOP)
- introduction of CCF support including migration workarounds and
  backwards compatibility, device tree updates (2/17 - 7/17)
  (nevertheless I suggest to take the .dts/.dtsi updates through the
  PowerPC tree, the extensions are straight forward and strictly are
  clock related, and complement the CCF platform support)
- peripheral driver adjustment to the CCF approach (8/17 - 16/17)
- removal of migration workarounds (17/17)

at device tree maintainers:

- the series does not introduce new bindings, but implements the
  existing clock binding (OF clock provider, DT based clock lookup) and
  so adjusts and extends DTS files
- the code is backwards compatible, and keeps working with device trees
  which don't contain clock related information


the series is based on v3.12, but I'll rebase against v3.13-rc1 (when
available) or any other subtree upon request

the series passes 'checkpatch.pl --strict' except for one warning which
cannot get resolved, since the <linux/clk-provider.h> API dictates the
data type, "fixing" the checkpatch warning would break compilation

  WARNING: static const char * array should probably be static const char * const
  #420: FILE: arch/powerpc/platforms/512x/clock-commonclk.c:342:
  +static const char *parent_names_mux0[] = {

  total: 0 errors, 1 warnings, 0 checks, 834 lines checked

checkpatch appears to choke on the NODE_CHK() macro in the backwards
compat patch, while I cannot see why since it groks the FOR_NODES() and
NODE_PREP() macros

  Use of uninitialized value $c in pattern match (m//) at ./scripts/checkpatch.pl line 3280.
  Use of uninitialized value in substr at ./scripts/checkpatch.pl line 3287.
  Use of uninitialized value $s in substr at ./scripts/checkpatch.pl line 3287.


the series has been build tested (each step on PowerPC 512x, 52xx, 5xxx
multi platform, 83xx, 85xx, 86xx, and on ARM v6/v7), run tested (each
step on 512x, the switch to CCF on 52xx), and tested for backwards
compatibility (each step on 512x with a v3.11 dtb)


changes in v5:
- extend comments in the PCI driver cleanup (probe() vs setup_arch()
  discussion, no code change); all other peripheral driver cleanup from
  v4 was taken into mainline
- concentrate migration support in a separate routine for improved
  maintainability
- fix the oscillator frequency lookup ('osc' reference) in the CCF
  platform support code which creates the clock tree
- add backwards compatibility with device trees that lack clock specs,
  concentrate compat support in a separate routine for improved
  maintainability, add it in a separate patch for easier review
- consistent use of the 'ipg' name in DTS files for the register access
  clock item of peripherals
- switch from PPC_CLOCK to COMMON_CLK at the same time for 512x and 52xx
  (keep multi-platform setups operational), in a separate patch
- move removal of migration support to the very end of the series, it's
  no longer intertwined with peripheral driver adjustment
- SPI and UART: get 'mclk' and 'ipg' clock items in a more consistent
  order (less obfuscation in the diff)
- add/adjust Cc: and Acked-By: entries, rework commit messages and
  comments where appropriate

changes in v4:
- remove explicit devm_clk_put() calls as these will occur implicitly
  upon device release (01/31, 02/31, 03/31, 04/31, 05/31, 06/31, 08/31,
  09/31, 27/31)
- split the PSC (SPI, UART) and MSCAN (CAN) related MCLK subtrees into
  separate 'ipg'/'bdlc' gated clock items for register access as well as
  the 'mclk' clock subtrees that apply to bitrates -- this eliminates
  the need for "shared gates" and further reduces clock pre-enable
  workarounds (11/31, 15/31, 17/31, 18/31, 20/31, 21/31, 22/31, 27/31)
- further adjust the CAN clock driver, fix an incomplete error code path
  in the network device open callback (11/31), only enable the bitrate
  clock when the network device is open (27/31)
- remove debug output in the clock tree setup when introducing the
  platform's clock driver, there already is CONFIG_COMMON_CLK_DEBUG to
  retrieve more complete information (17/31)
- remove an "enums don't work here" comment in the dt-bindings header
  file (15/31)
- reword and update commit messages (body and/or subject) where
  appropriate (03/31, 04/31, 05/31, 06/31, 08/31, 09/31, 11/31, 12/31,
  17/31, 20/31, 21/31, 22/31, 27/31, 28/31, 30/31, 31/31)
- add 'Reviewed-By' attributes which were received for v3

changes in v3:
- rebase the series against v3.11-rc2
- re-ordered the series to first address all general clock handling
  concerns in existing drivers, before introducing common clock support
  in the platform's clock driver
- slightly rework the SPI (01/31), UART (02/31), and PSC FIFO (23/31)
  clock handling in comparison to v2 which introduced those fixes
  (devm_{get,put}_clk() calls, fewer goto labels in error paths)
- fix and improve clock handling (balance allocation and release of
  clocks, check for errors during setup) in all of the other drivers
  which this series has touched before in naive ways: USB (03/31), NAND
  flash (04/31), video capture (05/31), I2C (06/31), ethernet (08/31),
  PCI (09/31), CAN (11/31)
- silence a build warning in the ethernet driver (07/31)
- eliminate all PPC_CLOCK references, use 'per' clock names for NAND
  flash (25/31) and VIU (26/31) as well
- unbreak CAN operation for the period between introducing common clock
  support in the platform's clock driver and introducing common clock
  support in the CAN peripheral driver as well as providing clock specs
  in the device tree (provide clkdev aliases for SYS and REF)
- improve common clock support for CAN (devm_{get,put}_clk() calls,
  check enable() errors, keep a reference to used clocks, disable and
  put clocks after use)
- reworded several commit messages to better reflect the kind of change
  and because fixes were applied before adding common infrastructure
  support
- point to individual numbered patches of the series in the list of
  changes for v2 as well

changes in v2:
- cleanup of the UART (02/24) and SPI (01/24) clock handling before the
  introduction of common clock support for the platform, as incomplete
  clock handling becomes fatal or more dangerous later (which in turn
  changes the context of the "device tree lookup only" followup patch
  later)
- reordered the sequence of patches to keep the serial communication
  related parts together (UART, SPI, and PSC FIFO changes after common
  clock support was introduced, which have become 11-14/24 now)
- updated commit messages for the clock API use cleanup in the serial
  communication drivers, updated comments and reworded commit messages
  in the core clock driver to expand on the pre-enable workaround and
  clkdev registration (09/24)
- keep a reference to the PSC FIFO clock during use instead of looking
  up the clock again in the uninit() routine (14/24)
- remove the clkdev.h header file inclusion directive with the removal
  of the clkdev registration call (13/24)


Gerhard Sittig (17):
  powerpc/fsl-pci: improve clock API use
  dts: mpc512x: introduce dt-bindings/clock/ header
  dts: mpc512x: add clock related device tree specs
  clk: mpc512x: introduce COMMON_CLK for MPC512x (disabled)
  clk: mpc512x: add backwards compat to the CCF code
  dts: mpc512x: add clock specs for client lookups
  clk: mpc5xxx: switch to COMMON_CLK, retire PPC_CLOCK
  spi: mpc512x: adjust to OF based clock lookup
  serial: mpc512x: adjust for OF based clock lookup
  serial: mpc512x: setup the PSC FIFO clock as well
  USB: fsl-mph-dr-of: adjust for OF based clock lookup
  mtd: mpc5121_nfc: adjust for OF based clock lookup
  [media] fsl-viu: adjust for OF based clock lookup
  net: can: mscan: adjust to common clock support for mpc512x
  net: can: mscan: remove non-CCF code for MPC512x
  powerpc/mpc512x: improve DIU related clock setup
  clk: mpc512x: remove migration support workarounds

 arch/powerpc/Kconfig                          |    5 -
 arch/powerpc/boot/dts/ac14xx.dts              |    7 +
 arch/powerpc/boot/dts/mpc5121.dtsi            |  113 ++-
 arch/powerpc/kernel/Makefile                  |    1 -
 arch/powerpc/kernel/clock.c                   |   82 ---
 arch/powerpc/platforms/512x/Kconfig           |    2 +-
 arch/powerpc/platforms/512x/Makefile          |    3 +-
 arch/powerpc/platforms/512x/clock-commonclk.c |  950 +++++++++++++++++++++++++
 arch/powerpc/platforms/512x/clock.c           |  753 --------------------
 arch/powerpc/platforms/512x/mpc512x_shared.c  |  169 +++--
 arch/powerpc/platforms/52xx/Kconfig           |    2 +-
 arch/powerpc/sysdev/fsl_pci.c                 |   52 ++
 drivers/media/platform/fsl-viu.c              |    2 +-
 drivers/mtd/nand/mpc5121_nfc.c                |    2 +-
 drivers/net/can/mscan/mpc5xxx_can.c           |  270 ++++---
 drivers/spi/spi-mpc512x-psc.c                 |   26 +-
 drivers/tty/serial/mpc52xx_uart.c             |   90 ++-
 drivers/usb/host/fsl-mph-dr-of.c              |   13 +-
 include/dt-bindings/clock/mpc512x-clock.h     |   69 ++
 include/linux/clk-provider.h                  |   16 +
 20 files changed, 1556 insertions(+), 1071 deletions(-)
 delete mode 100644 arch/powerpc/kernel/clock.c
 create mode 100644 arch/powerpc/platforms/512x/clock-commonclk.c
 delete mode 100644 arch/powerpc/platforms/512x/clock.c
 create mode 100644 include/dt-bindings/clock/mpc512x-clock.h

-- 
1.7.10.4

[PATCH v5 01/17] powerpc/fsl-pci: improve clock API use

[Gerhard Sittig]

make the Freescale PCI driver get, prepare and enable the PCI clock
during probe(); the clock gets put upon device shutdown by the devm
approach

clock lookup is non-fatal as not all platforms may provide clock specs
in their device tree or implement a device tree based clock provider,
but failure to enable clocks after successful lookup is fatal

the driver appears to not have a remove() routine, so no reference to
the clock is kept during use, and the clock isn't released (the devm
approach will put the clock, but it won't get disabled or unprepared)

the 85xx/86xx platforms go through the probe() routine, where clock
lookup occurs and the clock gets acquired if one was specified; the
512x/83xx platforms don't pass through probe() but instead directly call
the add_bridge() routine at a point in time where the clock provider has
not been setup yet even if the platform implements one -- add comments
to the code paths as a reminder for the potential need of a workaround
in the platform's clock driver, and to keep awareness if code should get
re-arranged or moved

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Gerhard Sittig <gsi@denx.de>
---
 arch/powerpc/sysdev/fsl_pci.c |   52 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

diff --git a/arch/powerpc/sysdev/fsl_pci.c b/arch/powerpc/sysdev/fsl_pci.c
index ccfb50ddfe38..efa0916f61b6 100644
--- a/arch/powerpc/sysdev/fsl_pci.c
+++ b/arch/powerpc/sysdev/fsl_pci.c
@@ -17,6 +17,8 @@
  * Free Software Foundation;  either version 2 of the  License, or (at your
  * option) any later version.
  */
+
+#include <linux/clk.h>
 #include <linux/kernel.h>
 #include <linux/pci.h>
 #include <linux/delay.h>
@@ -755,6 +757,32 @@ int __init mpc83xx_add_bridge(struct device_node *dev)
 	const int *bus_range;
 	int primary;
 
+	/*
+	 * 85xx/86xx platforms take the path through the probe() routine
+	 * as one would expect, PCI related clocks get acquired there if
+	 * specified
+	 *
+	 * 83xx/512x _don't_ pass through probe(), this add_bridge()
+	 * routine instead is called from within .setup_arch() at a
+	 * point in time where clock providers haven't been setup yet;
+	 * so clocks cannot get acquired here -- lookup would always
+	 * fail even on those platforms which implement the provider
+	 *
+	 * there is no counterpart for add_bridge() just like there is
+	 * no remove() counterpart for probe(), so in either case the
+	 * PCI related clock won't get released, and all of the
+	 * 512x/83xx/85xx/86xx platforms behave in identical ways
+	 *
+	 * this comment is here to "keep the balance" against the
+	 * probe() routine, and as a reminder to acquire clocks if the
+	 * add_bridge() call should move to some later point in time
+	 *
+	 * until then clock providers are expected to work around the
+	 * peripheral driver's not acquiring the PCI clock on those
+	 * platforms where clock providers exist, while nothing needs to
+	 * be done for those platforms without a clock provider
+	 */
+
 	is_mpc83xx_pci = 1;
 
 	if (!of_device_is_available(dev)) {
@@ -1086,9 +1114,33 @@ void fsl_pci_assign_primary(void)
 
 static int fsl_pci_probe(struct platform_device *pdev)
 {
+	struct clk *clk;
 	int ret;
 	struct device_node *node;
 
+	/*
+	 * clock lookup is non-fatal since the driver is shared among
+	 * platforms and not all of them provide clocks specs in their
+	 * device tree, but failure to enable a specified clock is
+	 * considered fatal
+	 *
+	 * note that only the 85xx and 86xx platforms pass through this
+	 * probe() routine, while 83xx and 512x directly invoke the
+	 * mpc83xx_add_bridge() routine from within .setup_arch() code
+	 */
+	clk = devm_clk_get(&pdev->dev, "ipg");
+	if (!IS_ERR(clk)) {
+		ret = clk_prepare_enable(clk);
+		if (ret) {
+			dev_err(&pdev->dev, "Could not enable PCI clock\n");
+			return ret;
+		}
+		/*
+		 * TODO where to store the 'clk' reference?  there appears
+		 * to be no remove() routine which undoes what probe() does
+		 */
+	}
+
 	node = pdev->dev.of_node;
 	ret = fsl_add_bridge(pdev, fsl_pci_primary == node);
 
-- 
1.7.10.4

[PATCH v5 02/17] dts: mpc512x: introduce dt-bindings/clock/ header

[Gerhard Sittig]

introduce a dt-bindings/ header file for MPC512x clocks,
providing symbolic identifiers for those SoC clocks which
clients will reference from their device tree nodes

Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: devicetree@vger.kernel.org
Reviewed-by: Mike Turquette <mturquette@linaro.org>	# for v3: w/o bdlc, PSC ipg
Signed-off-by: Gerhard Sittig <gsi@denx.de>
---
 include/dt-bindings/clock/mpc512x-clock.h |   69 +++++++++++++++++++++++++++++
 1 file changed, 69 insertions(+)
 create mode 100644 include/dt-bindings/clock/mpc512x-clock.h

diff --git a/include/dt-bindings/clock/mpc512x-clock.h b/include/dt-bindings/clock/mpc512x-clock.h
new file mode 100644
index 000000000000..9e81b3b99a32
--- /dev/null
+++ b/include/dt-bindings/clock/mpc512x-clock.h
@@ -0,0 +1,69 @@
+/*
+ * This header provides constants for MPC512x clock specs in DT bindings.
+ */
+
+#ifndef _DT_BINDINGS_CLOCK_MPC512x_CLOCK_H
+#define _DT_BINDINGS_CLOCK_MPC512x_CLOCK_H
+
+#define MPC512x_CLK_DUMMY		0
+#define MPC512x_CLK_REF			1
+#define MPC512x_CLK_SYS			2
+#define MPC512x_CLK_DIU			3
+#define MPC512x_CLK_VIU			4
+#define MPC512x_CLK_CSB			5
+#define MPC512x_CLK_E300		6
+#define MPC512x_CLK_IPS			7
+#define MPC512x_CLK_FEC			8
+#define MPC512x_CLK_SATA		9
+#define MPC512x_CLK_PATA		10
+#define MPC512x_CLK_NFC			11
+#define MPC512x_CLK_LPC			12
+#define MPC512x_CLK_MBX_BUS		13
+#define MPC512x_CLK_MBX			14
+#define MPC512x_CLK_MBX_3D		15
+#define MPC512x_CLK_AXE			16
+#define MPC512x_CLK_USB1		17
+#define MPC512x_CLK_USB2		18
+#define MPC512x_CLK_I2C			19
+#define MPC512x_CLK_MSCAN0_MCLK		20
+#define MPC512x_CLK_MSCAN1_MCLK		21
+#define MPC512x_CLK_MSCAN2_MCLK		22
+#define MPC512x_CLK_MSCAN3_MCLK		23
+#define MPC512x_CLK_BDLC		24
+#define MPC512x_CLK_SDHC		25
+#define MPC512x_CLK_PCI			26
+#define MPC512x_CLK_PSC_MCLK_IN		27
+#define MPC512x_CLK_SPDIF_TX		28
+#define MPC512x_CLK_SPDIF_RX		29
+#define MPC512x_CLK_SPDIF_MCLK		30
+#define MPC512x_CLK_SPDIF		31
+#define MPC512x_CLK_AC97		32
+#define MPC512x_CLK_PSC0_MCLK		33
+#define MPC512x_CLK_PSC1_MCLK		34
+#define MPC512x_CLK_PSC2_MCLK		35
+#define MPC512x_CLK_PSC3_MCLK		36
+#define MPC512x_CLK_PSC4_MCLK		37
+#define MPC512x_CLK_PSC5_MCLK		38
+#define MPC512x_CLK_PSC6_MCLK		39
+#define MPC512x_CLK_PSC7_MCLK		40
+#define MPC512x_CLK_PSC8_MCLK		41
+#define MPC512x_CLK_PSC9_MCLK		42
+#define MPC512x_CLK_PSC10_MCLK		43
+#define MPC512x_CLK_PSC11_MCLK		44
+#define MPC512x_CLK_PSC_FIFO		45
+#define MPC512x_CLK_PSC0		46
+#define MPC512x_CLK_PSC1		47
+#define MPC512x_CLK_PSC2		48
+#define MPC512x_CLK_PSC3		49
+#define MPC512x_CLK_PSC4		50
+#define MPC512x_CLK_PSC5		51
+#define MPC512x_CLK_PSC6		52
+#define MPC512x_CLK_PSC7		53
+#define MPC512x_CLK_PSC8		54
+#define MPC512x_CLK_PSC9		55
+#define MPC512x_CLK_PSC10		56
+#define MPC512x_CLK_PSC11		57
+
+#define MPC512x_CLK_LAST_PUBLIC		57
+
+#endif
-- 
1.7.10.4

[PATCH v5 03/17] dts: mpc512x: add clock related device tree specs

[Gerhard Sittig]

this addresses the clock driver aka provider's side of clocks
- introduce a 'clocks' subtree with an 'osc' node for the crystal
  or oscillator SoC input (fixed frequency)
- the 'clock@f00' clock-control-module node references the 'osc' for
  its input, and is another provider for all the clocks which the
  CCM component manages
- prepare for future references to clocks from peripheral nodes
  by means of the <&clks ID> syntax and symbolic ID names which a
  header file provides
- provide default values with 33MHz oscillator frequency in the
  common include (the 66MHz IPS bus already was there), and add
  override values for the ifm AC14xx board which deviates from
  the reference design (25MHz xtal, 80MHz IPS bus)

Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: devicetree@vger.kernel.org
Reviewed-by: Mike Turquette <mturquette@linaro.org> # for v3, before &osc
Signed-off-by: Gerhard Sittig <gsi@denx.de>
---
 arch/powerpc/boot/dts/ac14xx.dts   |    7 +++++++
 arch/powerpc/boot/dts/mpc5121.dtsi |   18 +++++++++++++++++-
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/boot/dts/ac14xx.dts b/arch/powerpc/boot/dts/ac14xx.dts
index a543c4088cba..a1b883730b31 100644
--- a/arch/powerpc/boot/dts/ac14xx.dts
+++ b/arch/powerpc/boot/dts/ac14xx.dts
@@ -139,7 +139,14 @@
 		};
 	};
 
+	clocks {
+		osc {
+			clock-frequency = <25000000>;
+		};
+	};
+
 	soc@80000000 {
+		bus-frequency = <80000000>;	/* 80 MHz ips bus */
 
 		clock@f00 {
 			compatible = "fsl,mpc5121rev2-clock", "fsl,mpc5121-clock";
diff --git a/arch/powerpc/boot/dts/mpc5121.dtsi b/arch/powerpc/boot/dts/mpc5121.dtsi
index bd14c00e5146..9bfcb7558197 100644
--- a/arch/powerpc/boot/dts/mpc5121.dtsi
+++ b/arch/powerpc/boot/dts/mpc5121.dtsi
@@ -9,6 +9,8 @@
  * option) any later version.
  */
 
+#include <dt-bindings/clock/mpc512x-clock.h>
+
 /dts-v1/;
 
 / {
@@ -73,6 +75,17 @@
 		ranges = <0x0 0x0 0xfc000000 0x04000000>;
 	};
 
+	clocks {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		osc: osc {
+			compatible = "fixed-clock";
+			#clock-cells = <0>;
+			clock-frequency = <33000000>;
+		};
+	};
+
 	soc@80000000 {
 		compatible = "fsl,mpc5121-immr";
 		#address-cells = <1>;
@@ -118,9 +131,12 @@
 		};
 
 		/* Clock control */
-		clock@f00 {
+		clks: clock@f00 {
 			compatible = "fsl,mpc5121-clock";
 			reg = <0xf00 0x100>;
+			#clock-cells = <1>;
+			clocks = <&osc>;
+			clock-names = "osc";
 		};
 
 		/* Power Management Controller */
-- 
1.7.10.4

[PATCH v5 04/17] clk: mpc512x: introduce COMMON_CLK for MPC512x (disabled)

[Gerhard Sittig]

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>
---
 arch/powerpc/platforms/512x/Makefile          |    4 +-
 arch/powerpc/platforms/512x/clock-commonclk.c |  797 +++++++++++++++++++++++++
 include/linux/clk-provider.h                  |   16 +
 3 files changed, 816 insertions(+), 1 deletion(-)
 create mode 100644 arch/powerpc/platforms/512x/clock-commonclk.c

diff --git a/arch/powerpc/platforms/512x/Makefile b/arch/powerpc/platforms/512x/Makefile
index 72fb9340e09f..1e05f9def8a4 100644
--- a/arch/powerpc/platforms/512x/Makefile
+++ b/arch/powerpc/platforms/512x/Makefile
@@ -1,7 +1,9 @@
 #
 # Makefile for the Freescale PowerPC 512x linux kernel.
 #
-obj-y				+= clock.o mpc512x_shared.o
+obj-$(CONFIG_PPC_CLOCK)		+= clock.o
+obj-$(CONFIG_COMMON_CLK)	+= clock-commonclk.o
+obj-y				+= mpc512x_shared.o
 obj-$(CONFIG_MPC5121_ADS)	+= mpc5121_ads.o mpc5121_ads_cpld.o
 obj-$(CONFIG_MPC512x_GENERIC)	+= mpc512x_generic.o
 obj-$(CONFIG_PDM360NG)		+= pdm360ng.o
diff --git a/arch/powerpc/platforms/512x/clock-commonclk.c b/arch/powerpc/platforms/512x/clock-commonclk.c
new file mode 100644
index 000000000000..ddbeaec79246
--- /dev/null
+++ b/arch/powerpc/platforms/512x/clock-commonclk.c
@@ -0,0 +1,797 @@
+/*
+ * Copyright (C) 2013 DENX Software Engineering
+ *
+ * Gerhard Sittig, <gsi@denx.de>
+ *
+ * common clock driver support for the MPC512x platform
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/io.h>
+#include <linux/of.h>
+
+#include <asm/mpc5121.h>
+#include <dt-bindings/clock/mpc512x-clock.h>
+
+#include "mpc512x.h"		/* our public mpc5121_clk_init() API */
+
+/* helpers to keep the MCLK intermediates "somewhere" in our table */
+enum {
+	MCLK_IDX_MUX0,
+	MCLK_IDX_EN0,
+	MCLK_IDX_DIV0,
+	MCLK_MAX_IDX,
+};
+
+#define NR_PSCS			12
+#define NR_MSCANS		4
+#define NR_SPDIFS		1
+#define NR_MCLKS		(NR_PSCS + NR_MSCANS + NR_SPDIFS)
+
+/* extend the public set of clocks by adding internal slots for management */
+enum {
+	/* arrange for adjacent numbers after the public set */
+	MPC512x_CLK_START_PRIVATE = MPC512x_CLK_LAST_PUBLIC,
+	/* clocks which aren't announced to the public */
+	MPC512x_CLK_DDR,
+	MPC512x_CLK_MEM,
+	MPC512x_CLK_IIM,
+	MPC512x_CLK_SDHC_2,
+	/* intermediates in div+gate combos or fractional dividers */
+	MPC512x_CLK_DDR_UG,
+	MPC512x_CLK_SDHC_x4,
+	MPC512x_CLK_SDHC_UG,
+	MPC512x_CLK_DIU_x4,
+	MPC512x_CLK_DIU_UG,
+	MPC512x_CLK_MBX_BUS_UG,
+	MPC512x_CLK_MBX_UG,
+	MPC512x_CLK_MBX_3D_UG,
+	MPC512x_CLK_PCI_UG,
+	MPC512x_CLK_NFC_UG,
+	MPC512x_CLK_LPC_UG,
+	MPC512x_CLK_SPDIF_TX_IN,
+	/* intermediates for the mux+gate+div+mux MCLK generation */
+	MPC512x_CLK_MCLKS_FIRST,
+	MPC512x_CLK_MCLKS_LAST = MPC512x_CLK_MCLKS_FIRST
+				+ NR_MCLKS * MCLK_MAX_IDX,
+	/* internal, symbolic spec for the number of slots */
+	MPC512x_CLK_LAST_PRIVATE,
+};
+
+/* data required for the OF clock provider registration */
+static struct clk *clks[MPC512x_CLK_LAST_PRIVATE];
+static struct clk_onecell_data clk_data;
+
+/* CCM register access */
+static struct mpc512x_ccm __iomem *clkregs;
+static DEFINE_SPINLOCK(clklock);
+
+/* convenience wrappers around the common clk API */
+static inline struct clk *mpc512x_clk_fixed(const char *name, int rate)
+{
+	return clk_register_fixed_rate(NULL, name, NULL, CLK_IS_ROOT, rate);
+}
+
+static inline struct clk *mpc512x_clk_factor(
+	const char *name, const char *parent_name,
+	int mul, int div)
+{
+	int clkflags;
+
+	clkflags = CLK_SET_RATE_PARENT;
+	return clk_register_fixed_factor(NULL, name, parent_name, clkflags,
+					 mul, div);
+}
+
+static inline struct clk *mpc512x_clk_divider(
+	const char *name, const char *parent_name, u8 clkflags,
+	u32 __iomem *reg, u8 pos, u8 len, int divflags)
+{
+	return clk_register_divider(NULL, name, parent_name, clkflags,
+				    reg, pos, len, divflags, &clklock);
+}
+
+static inline struct clk *mpc512x_clk_divtable(
+	const char *name, const char *parent_name,
+	u32 __iomem *reg, u8 pos, u8 len,
+	const struct clk_div_table *divtab)
+{
+	u8 divflags;
+
+	divflags = 0;
+	return clk_register_divider_table(NULL, name, parent_name, 0,
+					  reg, pos, len, divflags,
+					  divtab, &clklock);
+}
+
+static inline struct clk *mpc512x_clk_gated(
+	const char *name, const char *parent_name,
+	u32 __iomem *reg, u8 pos)
+{
+	int clkflags;
+
+	clkflags = CLK_SET_RATE_PARENT;
+	return clk_register_gate(NULL, name, parent_name, clkflags,
+				 reg, pos, 0, &clklock);
+}
+
+static inline struct clk *mpc512x_clk_muxed(const char *name,
+	const char **parent_names, int parent_count,
+	u32 __iomem *reg, u8 pos, u8 len)
+{
+	int clkflags;
+	u8 muxflags;
+
+	clkflags = CLK_SET_RATE_PARENT;
+	muxflags = 0;
+	return clk_register_mux(NULL, name,
+				parent_names, parent_count, clkflags,
+				reg, pos, len, muxflags, &clklock);
+}
+
+/* helper to isolate a bit field from a register */
+static inline int get_bit_field(uint32_t __iomem *reg, uint8_t pos, uint8_t len)
+{
+	uint32_t val;
+
+	val = in_be32(reg);
+	val >>= pos;
+	val &= (1 << len) - 1;
+	return val;
+}
+
+/* get the SPMF and translate it into the "sys pll" multiplier */
+static int get_spmf_mult(void)
+{
+	static int spmf_to_mult[] = {
+		68, 1, 12, 16, 20, 24, 28, 32,
+		36, 40, 44, 48, 52, 56, 60, 64,
+	};
+	int spmf;
+
+	spmf = get_bit_field(&clkregs->spmr, 24, 4);
+	return spmf_to_mult[spmf];
+}
+
+/*
+ * get the SYS_DIV value and translate it into a divide factor
+ *
+ * values returned from here are a multiple of the real factor since the
+ * divide ratio is fractional
+ */
+static int get_sys_div_x2(void)
+{
+	static int sysdiv_code_to_x2[] = {
+		4, 5, 6, 7, 8, 9, 10, 14,
+		12, 16, 18, 22, 20, 24, 26, 30,
+		28, 32, 34, 38, 36, 40, 42, 46,
+		44, 48, 50, 54, 52, 56, 58, 62,
+		60, 64, 66,
+	};
+	int divcode;
+
+	divcode = get_bit_field(&clkregs->scfr2, 26, 6);
+	return sysdiv_code_to_x2[divcode];
+}
+
+/*
+ * get the CPMF value and translate it into a multiplier factor
+ *
+ * values returned from here are a multiple of the real factor since the
+ * multiplier ratio is fractional
+ */
+static int get_cpmf_mult_x2(void)
+{
+	static int cpmf_to_mult[] = {
+		72, 2, 2, 3, 4, 5, 6, 7,
+	};
+	int cpmf;
+
+	cpmf = get_bit_field(&clkregs->spmr, 16, 4);
+	return cpmf_to_mult[cpmf];
+}
+
+/*
+ * some of the clock dividers do scale in a linear way, yet not all of
+ * their bit combinations are legal; use a divider table to get a
+ * resulting set of applicable divider values
+ */
+
+/* applies to the IPS_DIV, and PCI_DIV values */
+static struct clk_div_table divtab_2346[] = {
+	{ .val = 2, .div = 2, },
+	{ .val = 3, .div = 3, },
+	{ .val = 4, .div = 4, },
+	{ .val = 6, .div = 6, },
+	{ .div = 0, },
+};
+
+/* applies to the MBX_DIV, LPC_DIV, and NFC_DIV values */
+static struct clk_div_table divtab_1234[] = {
+	{ .val = 1, .div = 1, },
+	{ .val = 2, .div = 2, },
+	{ .val = 3, .div = 3, },
+	{ .val = 4, .div = 4, },
+	{ .div = 0, },
+};
+
+static int get_freq_from_dt(char *propname)
+{
+	struct device_node *np;
+	const unsigned int *prop;
+	int val;
+
+	val = 0;
+	np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-immr");
+	if (np) {
+		prop = of_get_property(np, propname, NULL);
+		if (prop)
+			val = *prop;
+	    of_node_put(np);
+	}
+	return val;
+}
+
+static void mpc512x_clk_preset_data(void)
+{
+	size_t i;
+
+	for (i = 0; i < ARRAY_SIZE(clks); i++)
+		clks[i] = ERR_PTR(-ENODEV);
+}
+
+/*
+ * - receives the "bus frequency" from the caller (that's the IPS clock
+ *   rate, the historical source of clock information)
+ * - fetches the system PLL multiplier and divider values as well as the
+ *   IPS divider value from hardware
+ * - determines the REF clock rate either from the XTAL/OSC spec (if
+ *   there is a device tree node describing the oscillator) or from the
+ *   IPS bus clock (supported for backwards compatibility, such that
+ *   setups without XTAL/OSC specs keep working)
+ * - creates the "ref" clock item in the clock tree, such that
+ *   subsequent code can create the remainder of the hierarchy (REF ->
+ *   SYS -> CSB -> IPS) from the REF clock rate and the returned mul/div
+ *   values
+ */
+static void mpc512x_clk_setup_ref_clock(struct device_node *np, int bus_freq,
+					int *sys_mul, int *sys_div,
+					int *ips_div)
+{
+	struct clk *osc_clk;
+	int calc_freq;
+
+	/* fetch mul/div factors from the hardware */
+	*sys_mul = get_spmf_mult();
+	*sys_mul *= 2;		/* compensate for the fractional divider */
+	*sys_div = get_sys_div_x2();
+	*ips_div = get_bit_field(&clkregs->scfr1, 23, 3);
+
+	/* lookup the oscillator clock for its rate */
+	osc_clk = of_clk_get_by_name(np, "osc");
+
+	/*
+	 * either descend from OSC to REF (and in bypassing verify the
+	 * IPS rate), or backtrack from IPS and multiplier values that
+	 * were fetched from hardware to REF and thus to the OSC value
+	 *
+	 * in either case the REF clock gets created here and the
+	 * remainder of the clock tree can get spanned from there
+	 */
+	if (!IS_ERR(osc_clk)) {
+		clks[MPC512x_CLK_REF] = mpc512x_clk_factor("ref", "osc", 1, 1);
+		calc_freq = clk_get_rate(clks[MPC512x_CLK_REF]);
+		calc_freq *= *sys_mul;
+		calc_freq /= *sys_div;
+		calc_freq /= 2;
+		calc_freq /= *ips_div;
+		if (bus_freq && calc_freq != bus_freq)
+			pr_warn("calc rate %d != OF spec %d\n",
+				calc_freq, bus_freq);
+	} else {
+		calc_freq = bus_freq;	/* start with IPS */
+		calc_freq *= *ips_div;	/* IPS -> CSB */
+		calc_freq *= 2;		/* CSB -> SYS */
+		calc_freq *= *sys_div;	/* SYS -> PLL out */
+		calc_freq /= *sys_mul;	/* PLL out -> REF == OSC */
+		clks[MPC512x_CLK_REF] = mpc512x_clk_fixed("ref", calc_freq);
+	}
+}
+
+/*
+ * helper code for the MCLK subtree setup
+ *
+ * the overview in section 5.2.4 of the MPC5121e Reference Manual rev4
+ * suggests that all instances of the "PSC clock generation" are equal,
+ * and that one might re-use the PSC setup for MSCAN clock generation
+ * (section 5.2.5) as well, at least the logic if not the data for
+ * description
+ *
+ * the details (starting at page 5-20) show differences in the specific
+ * inputs of the first mux stage ("can clk in", "spdif tx"), and the
+ * factual non-availability of the second mux stage (it's present yet
+ * only one input is valid)
+ *
+ * the MSCAN clock related registers (starting at page 5-35) all
+ * reference "spdif clk" at the first mux stage and don't mention any
+ * "can clk" at all, which somehow is unexpected
+ *
+ * TODO re-check the document, and clarify whether the RM is correct in
+ * the overview or in the details, and whether the difference is a
+ * clipboard induced error or results from chip revisions
+ *
+ * it turns out that the RM rev4 as of 2012-06 talks about "can" for the
+ * PSCs while RM rev3 as of 2008-10 talks about "spdif", so I guess that
+ * first a doc update is required which better reflects reality in the
+ * SoC before the implementation should follow while no questions remain
+ */
+
+/*
+ * note that this declaration raises a checkpatch warning, but
+ * it's the very data type which <linux/clk-provider.h> expects,
+ * making this declaration pass checkpatch will break compilation
+ */
+static const char *parent_names_mux0[] = {
+	"sys", "ref", "psc-mclk-in", "spdif-tx",
+};
+
+enum mclk_type {
+	MCLK_TYPE_PSC,
+	MCLK_TYPE_MSCAN,
+	MCLK_TYPE_SPDIF,
+};
+
+struct mclk_setup_data {
+	enum mclk_type type;
+	bool has_mclk1;
+	const char *name_mux0;
+	const char *name_en0;
+	const char *name_div0;
+	const char *parent_names_mux1[2];
+	const char *name_mclk;
+};
+
+#define MCLK_SETUP_DATA_PSC(id) { \
+	MCLK_TYPE_PSC, 0, \
+	"psc" #id "-mux0", \
+	"psc" #id "-en0", \
+	"psc" #id "_mclk_div", \
+	{ "psc" #id "_mclk_div", "dummy", }, \
+	"psc" #id "_mclk", \
+}
+
+#define MCLK_SETUP_DATA_MSCAN(id) { \
+	MCLK_TYPE_MSCAN, 0, \
+	"mscan" #id "-mux0", \
+	"mscan" #id "-en0", \
+	"mscan" #id "_mclk_div", \
+	{ "mscan" #id "_mclk_div", "dummy", }, \
+	"mscan" #id "_mclk", \
+}
+
+#define MCLK_SETUP_DATA_SPDIF { \
+	MCLK_TYPE_SPDIF, 1, \
+	"spdif-mux0", \
+	"spdif-en0", \
+	"spdif_mclk_div", \
+	{ "spdif_mclk_div", "spdif-rx", }, \
+	"spdif_mclk", \
+}
+
+static struct mclk_setup_data mclk_psc_data[] = {
+	MCLK_SETUP_DATA_PSC(0),
+	MCLK_SETUP_DATA_PSC(1),
+	MCLK_SETUP_DATA_PSC(2),
+	MCLK_SETUP_DATA_PSC(3),
+	MCLK_SETUP_DATA_PSC(4),
+	MCLK_SETUP_DATA_PSC(5),
+	MCLK_SETUP_DATA_PSC(6),
+	MCLK_SETUP_DATA_PSC(7),
+	MCLK_SETUP_DATA_PSC(8),
+	MCLK_SETUP_DATA_PSC(9),
+	MCLK_SETUP_DATA_PSC(10),
+	MCLK_SETUP_DATA_PSC(11),
+};
+
+static struct mclk_setup_data mclk_mscan_data[] = {
+	MCLK_SETUP_DATA_MSCAN(0),
+	MCLK_SETUP_DATA_MSCAN(1),
+	MCLK_SETUP_DATA_MSCAN(2),
+	MCLK_SETUP_DATA_MSCAN(3),
+};
+
+static struct mclk_setup_data mclk_spdif_data[] = {
+	MCLK_SETUP_DATA_SPDIF,
+};
+
+/* setup the MCLK clock subtree of an individual PSC/MSCAN/SPDIF */
+static void mpc512x_clk_setup_mclk(struct mclk_setup_data *entry, size_t idx)
+{
+	size_t clks_idx_pub, clks_idx_int;
+	u32 __iomem *mccr_reg;	/* MCLK control register (mux, en, div) */
+	int div;
+
+	/* derive a few parameters from the component type and index */
+	switch (entry->type) {
+	case MCLK_TYPE_PSC:
+		clks_idx_pub = MPC512x_CLK_PSC0_MCLK + idx;
+		clks_idx_int = MPC512x_CLK_MCLKS_FIRST
+			     + (idx) * MCLK_MAX_IDX;
+		mccr_reg = &clkregs->psc_ccr[idx];
+		break;
+	case MCLK_TYPE_MSCAN:
+		clks_idx_pub = MPC512x_CLK_MSCAN0_MCLK + idx;
+		clks_idx_int = MPC512x_CLK_MCLKS_FIRST
+			     + (NR_PSCS + idx) * MCLK_MAX_IDX;
+		mccr_reg = &clkregs->mscan_ccr[idx];
+		break;
+	case MCLK_TYPE_SPDIF:
+		clks_idx_pub = MPC512x_CLK_SPDIF_MCLK;
+		clks_idx_int = MPC512x_CLK_MCLKS_FIRST
+			     + (NR_PSCS + NR_MSCANS) * MCLK_MAX_IDX;
+		mccr_reg = &clkregs->spccr;
+		break;
+	default:
+		return;
+	}
+
+	/*
+	 * this was grabbed from the PPC_CLOCK implementation, which
+	 * enforced a specific MCLK divider while the clock was gated
+	 * during setup (that's a documented hardware requirement)
+	 *
+	 * the PPC_CLOCK implementation might even have violated the
+	 * "MCLK <= IPS" constraint, the fixed divider value of 1
+	 * results in a divider of 2 and thus MCLK = SYS/2 which equals
+	 * CSB which is greater than IPS; the serial port setup may have
+	 * adjusted the divider which the clock setup might have left in
+	 * an undesirable state
+	 *
+	 * initial setup is:
+	 * - MCLK 0 from SYS
+	 * - MCLK DIV such to not exceed the IPS clock
+	 * - MCLK 0 enabled
+	 * - MCLK 1 from MCLK DIV
+	 */
+	div = clk_get_rate(clks[MPC512x_CLK_SYS]);
+	div /= clk_get_rate(clks[MPC512x_CLK_IPS]);
+	out_be32(mccr_reg, (0 << 16));
+	out_be32(mccr_reg, (0 << 16) | ((div - 1) << 17));
+	out_be32(mccr_reg, (1 << 16) | ((div - 1) << 17));
+
+	/*
+	 * create the 'struct clk' items of the MCLK's clock subtree
+	 *
+	 * note that by design we always create all nodes and won't take
+	 * shortcuts here, because
+	 * - the "internal" MCLK_DIV and MCLK_OUT signal in turn are
+	 *   selectable inputs to the CFM while those who "actually use"
+	 *   the PSC/MSCAN/SPDIF (serial drivers et al) need the MCLK
+	 *   for their bitrate
+	 * - in the absence of "aliases" for clocks we need to create
+	 *   individial 'struct clk' items for whatever might get
+	 *   referenced or looked up, even if several of those items are
+	 *   identical from the logical POV (their rate value)
+	 * - for easier future maintenance and for better reflection of
+	 *   the SoC's documentation, it appears appropriate to generate
+	 *   clock items even for those muxers which actually are NOPs
+	 *   (those with two inputs of which one is reserved)
+	 */
+	clks[clks_idx_int + MCLK_IDX_MUX0] = mpc512x_clk_muxed(
+			entry->name_mux0,
+			&parent_names_mux0[0], ARRAY_SIZE(parent_names_mux0),
+			mccr_reg, 14, 2);
+	clks[clks_idx_int + MCLK_IDX_EN0] = mpc512x_clk_gated(
+			entry->name_en0, entry->name_mux0,
+			mccr_reg, 16);
+	clks[clks_idx_int + MCLK_IDX_DIV0] = mpc512x_clk_divider(
+			entry->name_div0,
+			entry->name_en0, CLK_SET_RATE_GATE,
+			mccr_reg, 17, 15, 0);
+	if (entry->has_mclk1) {
+		clks[clks_idx_pub] = mpc512x_clk_muxed(
+				entry->name_mclk,
+				&entry->parent_names_mux1[0],
+				ARRAY_SIZE(entry->parent_names_mux1),
+				mccr_reg, 7, 1);
+	} else {
+		clks[clks_idx_pub] = mpc512x_clk_factor(
+				entry->name_mclk,
+				entry->parent_names_mux1[0],
+				1, 1);
+	}
+}
+
+static void mpc512x_clk_setup_clock_tree(struct device_node *np, int busfreq)
+{
+	int sys_mul, sys_div, ips_div;
+	int mul, div;
+	size_t mclk_idx;
+	int freq;
+
+	/*
+	 * developer's notes:
+	 * - consider whether to handle clocks which have both gates and
+	 *   dividers via intermediates or by means of composites
+	 * - fractional dividers appear to not map well to composites
+	 *   since they can be seen as a fixed multiplier and an
+	 *   adjustable divider, while composites can only combine at
+	 *   most one of a mux, div, and gate each into one 'struct clk'
+	 *   item
+	 * - PSC/MSCAN/SPDIF clock generation OTOH already is very
+	 *   specific and cannot get mapped to componsites (at least not
+	 *   a single one, maybe two of them, but then some of these
+	 *   intermediate clock signals get referenced elsewhere (e.g.
+	 *   in the clock frequency measurement, CFM) and thus need
+	 *   publicly available names
+	 * - the current source layout appropriately reflects the
+	 *   hardware setup, and it works, so it's questionable whether
+	 *   further changes will result in big enough a benefit
+	 */
+
+	/* regardless of whether XTAL/OSC exists, have REF created */
+	mpc512x_clk_setup_ref_clock(np, busfreq, &sys_mul, &sys_div, &ips_div);
+
+	/* now setup the REF -> SYS -> CSB -> IPS hierarchy */
+	clks[MPC512x_CLK_SYS] = mpc512x_clk_factor("sys", "ref",
+						   sys_mul, sys_div);
+	clks[MPC512x_CLK_CSB] = mpc512x_clk_factor("csb", "sys", 1, 2);
+	clks[MPC512x_CLK_IPS] = mpc512x_clk_divtable("ips", "csb",
+						     &clkregs->scfr1, 23, 3,
+						     divtab_2346);
+
+	/* now setup anything below SYS and CSB and IPS */
+	clks[MPC512x_CLK_DDR_UG] = mpc512x_clk_factor("ddr-ug", "sys", 1, 2);
+	clks[MPC512x_CLK_SDHC_x4] = mpc512x_clk_factor("sdhc-x4", "csb", 4, 1);
+	clks[MPC512x_CLK_SDHC_UG] = mpc512x_clk_divider("sdhc-ug", "sdhc-x4", 0,
+							&clkregs->scfr2, 0, 8,
+							CLK_DIVIDER_ONE_BASED);
+	clks[MPC512x_CLK_DIU_x4] = mpc512x_clk_factor("diu-x4", "csb", 4, 1);
+	clks[MPC512x_CLK_DIU_UG] = mpc512x_clk_divider("diu-ug", "diu-x4", 0,
+						       &clkregs->scfr1, 0, 8,
+						       CLK_DIVIDER_ONE_BASED);
+
+	/*
+	 * the "power architecture PLL" was setup from data which was
+	 * sampled from the reset config word, at this point in time the
+	 * configuration can be considered fixed and read only (i.e. no
+	 * longer adjustable, or no longer in need of adjustment), which
+	 * is why we don't register a PLL here but assume fixed factors
+	 */
+	mul = get_cpmf_mult_x2();
+	div = 2;	/* compensate for the fractional factor */
+	clks[MPC512x_CLK_E300] = mpc512x_clk_factor("e300", "csb", mul, div);
+
+	clks[MPC512x_CLK_MBX_BUS_UG] = mpc512x_clk_factor("mbx-bus-ug", "csb",
+							  1, 2);
+	clks[MPC512x_CLK_MBX_UG] = mpc512x_clk_divtable("mbx-ug", "mbx-bus-ug",
+							&clkregs->scfr1, 14, 3,
+							divtab_1234);
+	clks[MPC512x_CLK_MBX_3D_UG] = mpc512x_clk_factor("mbx-3d-ug", "mbx-ug",
+							 1, 1);
+	clks[MPC512x_CLK_PCI_UG] = mpc512x_clk_divtable("pci-ug", "csb",
+							&clkregs->scfr1, 20, 3,
+							divtab_2346);
+	clks[MPC512x_CLK_NFC_UG] = mpc512x_clk_divtable("nfc-ug", "ips",
+							&clkregs->scfr1, 8, 3,
+							divtab_1234);
+	clks[MPC512x_CLK_LPC_UG] = mpc512x_clk_divtable("lpc-ug", "ips",
+							&clkregs->scfr1, 11, 3,
+							divtab_1234);
+
+	clks[MPC512x_CLK_LPC] = mpc512x_clk_gated("lpc", "lpc-ug",
+						  &clkregs->sccr1, 30);
+	clks[MPC512x_CLK_NFC] = mpc512x_clk_gated("nfc", "nfc-ug",
+						  &clkregs->sccr1, 29);
+	clks[MPC512x_CLK_PATA] = mpc512x_clk_gated("pata", "ips",
+						   &clkregs->sccr1, 28);
+	/* for PSCs there is a "registers" gate and a bitrate MCLK subtree */
+	for (mclk_idx = 0; mclk_idx < ARRAY_SIZE(mclk_psc_data); mclk_idx++) {
+		char name[12];
+		snprintf(name, sizeof(name), "psc%d", mclk_idx);
+		clks[MPC512x_CLK_PSC0 + mclk_idx] = mpc512x_clk_gated(
+				name, "ips", &clkregs->sccr1, 27 - mclk_idx);
+		mpc512x_clk_setup_mclk(&mclk_psc_data[mclk_idx], mclk_idx);
+	}
+	clks[MPC512x_CLK_PSC_FIFO] = mpc512x_clk_gated("psc-fifo", "ips",
+						       &clkregs->sccr1, 15);
+	clks[MPC512x_CLK_SATA] = mpc512x_clk_gated("sata", "ips",
+						   &clkregs->sccr1, 14);
+	clks[MPC512x_CLK_FEC] = mpc512x_clk_gated("fec", "ips",
+						  &clkregs->sccr1, 13);
+	clks[MPC512x_CLK_PCI] = mpc512x_clk_gated("pci", "pci-ug",
+						  &clkregs->sccr1, 11);
+	clks[MPC512x_CLK_DDR] = mpc512x_clk_gated("ddr", "ddr-ug",
+						  &clkregs->sccr1, 10);
+
+	clks[MPC512x_CLK_DIU] = mpc512x_clk_gated("diu", "diu-ug",
+						  &clkregs->sccr2, 31);
+	clks[MPC512x_CLK_AXE] = mpc512x_clk_gated("axe", "csb",
+						  &clkregs->sccr2, 30);
+	clks[MPC512x_CLK_MEM] = mpc512x_clk_gated("mem", "ips",
+						  &clkregs->sccr2, 29);
+	clks[MPC512x_CLK_USB1] = mpc512x_clk_gated("usb1", "csb",
+						   &clkregs->sccr2, 28);
+	clks[MPC512x_CLK_USB2] = mpc512x_clk_gated("usb2", "csb",
+						   &clkregs->sccr2, 27);
+	clks[MPC512x_CLK_I2C] = mpc512x_clk_gated("i2c", "ips",
+						  &clkregs->sccr2, 26);
+	/* MSCAN differs from PSC with just one gate for multiple components */
+	clks[MPC512x_CLK_BDLC] = mpc512x_clk_gated("bdlc", "ips",
+						   &clkregs->sccr2, 25);
+	for (mclk_idx = 0; mclk_idx < ARRAY_SIZE(mclk_mscan_data); mclk_idx++)
+		mpc512x_clk_setup_mclk(&mclk_mscan_data[mclk_idx], mclk_idx);
+	clks[MPC512x_CLK_SDHC] = mpc512x_clk_gated("sdhc", "sdhc-ug",
+						   &clkregs->sccr2, 24);
+	/* there is only one SPDIF component, which shares MCLK support code */
+	clks[MPC512x_CLK_SPDIF] = mpc512x_clk_gated("spdif", "ips",
+						    &clkregs->sccr2, 23);
+	mpc512x_clk_setup_mclk(&mclk_spdif_data[0], 0);
+	clks[MPC512x_CLK_MBX_BUS] = mpc512x_clk_gated("mbx-bus", "mbx-bus-ug",
+						      &clkregs->sccr2, 22);
+	clks[MPC512x_CLK_MBX] = mpc512x_clk_gated("mbx", "mbx-ug",
+						  &clkregs->sccr2, 21);
+	clks[MPC512x_CLK_MBX_3D] = mpc512x_clk_gated("mbx-3d", "mbx-3d-ug",
+						     &clkregs->sccr2, 20);
+	clks[MPC512x_CLK_IIM] = mpc512x_clk_gated("iim", "csb",
+						  &clkregs->sccr2, 19);
+	clks[MPC512x_CLK_VIU] = mpc512x_clk_gated("viu", "csb",
+						  &clkregs->sccr2, 18);
+	clks[MPC512x_CLK_SDHC_2] = mpc512x_clk_gated("sdhc-2", "sdhc-ug",
+						     &clkregs->sccr2, 17);
+
+	/*
+	 * externally provided clocks (when implemented in hardware,
+	 * device tree may specify values which otherwise were unknown)
+	 */
+	freq = get_freq_from_dt("psc_mclk_in");
+	if (!freq)
+		freq = 25000000;
+	clks[MPC512x_CLK_PSC_MCLK_IN] = mpc512x_clk_fixed("psc_mclk_in", freq);
+	freq = get_freq_from_dt("spdif_tx_in");
+	clks[MPC512x_CLK_SPDIF_TX_IN] = mpc512x_clk_fixed("spdif_tx_in", freq);
+	freq = get_freq_from_dt("spdif_rx_in");
+	clks[MPC512x_CLK_SPDIF_TX_IN] = mpc512x_clk_fixed("spdif_rx_in", freq);
+
+	/* fixed frequency for AC97, always 24.567MHz */
+	clks[MPC512x_CLK_AC97] = mpc512x_clk_fixed("ac97", 24567000);
+
+	/*
+	 * pre-enable those "internal" clock items which never get
+	 * claimed by any peripheral driver, to not have the clock
+	 * subsystem disable them late at startup
+	 */
+	clk_prepare_enable(clks[MPC512x_CLK_DUMMY]);
+	clk_prepare_enable(clks[MPC512x_CLK_E300]);	/* PowerPC CPU */
+	clk_prepare_enable(clks[MPC512x_CLK_DDR]);	/* DRAM */
+	clk_prepare_enable(clks[MPC512x_CLK_MEM]);	/* SRAM */
+	clk_prepare_enable(clks[MPC512x_CLK_IPS]);	/* SoC periph */
+	clk_prepare_enable(clks[MPC512x_CLK_LPC]);	/* boot media */
+}
+
+/*
+ * registers the set of public clocks (those listed in the dt-bindings/
+ * header file) for OF lookups, keeps the intermediates private to us
+ */
+static void mpc5121_clk_register_of_provider(struct device_node *np)
+{
+	clk_data.clks = clks;
+	clk_data.clk_num = MPC512x_CLK_LAST_PUBLIC + 1;	/* _not_ ARRAY_SIZE() */
+	of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
+}
+
+/*
+ * temporary support for the period of time between introduction of CCF
+ * support and the adjustment of peripheral drivers to OF based lookups
+ */
+static void mpc5121_clk_provide_migration_support(void)
+{
+	int idx;
+	char name[32];
+
+	/*
+	 * provide "pre-CCF" alias clock names for peripheral drivers
+	 * which have not yet been adjusted to do OF based clock lookups
+	 */
+	clk_register_clkdev(clks[MPC512x_CLK_REF], "ref_clk", NULL);
+	clk_register_clkdev(clks[MPC512x_CLK_SYS], "sys_clk", NULL);
+	clk_register_clkdev(clks[MPC512x_CLK_VIU], "viu_clk", NULL);
+	clk_register_clkdev(clks[MPC512x_CLK_NFC], "nfc_clk", NULL);
+	clk_register_clkdev(clks[MPC512x_CLK_USB1], "usb1_clk", NULL);
+	clk_register_clkdev(clks[MPC512x_CLK_USB2], "usb2_clk", NULL);
+	for (idx = 0; idx < NR_PSCS; idx++) {
+		snprintf(name, sizeof(name), "psc%d_mclk", idx);
+		clk_register_clkdev(clks[MPC512x_CLK_PSC0_MCLK + idx],
+				    name, NULL);
+	}
+	for (idx = 0; idx < NR_MSCANS; idx++) {
+		snprintf(name, sizeof(name), "mscan%d_mclk", idx);
+		clk_register_clkdev(clks[MPC512x_CLK_MSCAN0_MCLK + idx],
+				    name, NULL);
+	}
+	clk_register_clkdev(clks[MPC512x_CLK_SPDIF_MCLK], "spdif_mclk", NULL);
+
+	/*
+	 * pre-enable those clock items which are not yet appropriately
+	 * acquired by their peripheral driver
+	 */
+	clk_prepare_enable(clks[MPC512x_CLK_PSC_FIFO]);
+	clk_prepare_enable(clks[MPC512x_CLK_PSC3_MCLK]);/* serial console */
+	clk_prepare_enable(clks[MPC512x_CLK_FEC]);	/* network, NFS */
+	clk_prepare_enable(clks[MPC512x_CLK_DIU]);	/* display */
+	clk_prepare_enable(clks[MPC512x_CLK_I2C]);	/* I2C */
+	for (idx = 0; idx < NR_PSCS; idx++)		/* PSC ipg */
+		clk_prepare_enable(clks[MPC512x_CLK_PSC0 + idx]);
+	clk_prepare_enable(clks[MPC512x_CLK_BDLC]);	/* MSCAN ipg */
+	for (idx = 0; idx < NR_MSCANS; idx++)		/* MSCAN mclk */
+		clk_prepare_enable(clks[MPC512x_CLK_MSCAN0_MCLK + idx]);
+	clk_prepare_enable(clks[MPC512x_CLK_PCI]);	/* PCI */
+}
+
+/*
+ * register source code provided fallback results for clock lookups,
+ * these get consulted when OF based clock lookup fails (that is in the
+ * case of not yet adjusted device tree data, where clock related specs
+ * are missing)
+ */
+static void mpc5121_clk_provide_backwards_compat(void)
+{
+	/* TODO */
+}
+
+int __init mpc5121_clk_init(void)
+{
+	struct device_node *clk_np;
+	int busfreq;
+
+	/* map the clock control registers */
+	clk_np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-clock");
+	if (!clk_np)
+		return -ENODEV;
+	clkregs = of_iomap(clk_np, 0);
+	WARN_ON(!clkregs);
+
+	/* invalidate all not yet registered clock slots */
+	mpc512x_clk_preset_data();
+
+	/*
+	 * have the device tree scanned for "fixed-clock" nodes (which
+	 * includes the oscillator node if the board's DT provides one)
+	 */
+	of_clk_init(NULL);
+
+	/*
+	 * add a dummy clock for those situations where a clock spec is
+	 * required yet no real clock is involved
+	 */
+	clks[MPC512x_CLK_DUMMY] = mpc512x_clk_fixed("dummy", 0);
+
+	/*
+	 * have all the real nodes in the clock tree populated from REF
+	 * down to all leaves, either starting from the OSC node or from
+	 * a REF root that was created from the IPS bus clock input
+	 */
+	busfreq = get_freq_from_dt("bus-frequency");
+	mpc512x_clk_setup_clock_tree(clk_np, busfreq);
+
+	/* register as an OF clock provider */
+	mpc5121_clk_register_of_provider(clk_np);
+
+	/*
+	 * unbreak not yet adjusted peripheral drivers during migration
+	 * towards fully operational common clock support, and allow
+	 * operation in the absence of clock related device tree specs
+	 */
+	mpc5121_clk_provide_migration_support();
+	mpc5121_clk_provide_backwards_compat();
+
+	return 0;
+}
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 73bdb69f0c08..a21c5878973c 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -511,6 +511,20 @@ 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);
@@ -521,5 +535,7 @@ 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 */
-- 
1.7.10.4

[PATCH v5 05/17] clk: mpc512x: add backwards compat to the CCF code

[Gerhard Sittig]

extend the recently added COMMON_CLK platform support for MPC512x such
that it works with incomplete device tree data which lacks clock specs

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>
---
 arch/powerpc/platforms/512x/clock-commonclk.c |  173 ++++++++++++++++++++++++-
 1 file changed, 172 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/512x/clock-commonclk.c b/arch/powerpc/platforms/512x/clock-commonclk.c
index ddbeaec79246..c1faf3a9ea1f 100644
--- a/arch/powerpc/platforms/512x/clock-commonclk.c
+++ b/arch/powerpc/platforms/512x/clock-commonclk.c
@@ -11,6 +11,7 @@
  * (at your option) any later version.
  */
 
+#include <linux/bitops.h>
 #include <linux/clk-provider.h>
 #include <linux/clkdev.h>
 #include <linux/device.h>
@@ -744,7 +745,177 @@ static void mpc5121_clk_provide_migration_support(void)
  */
 static void mpc5121_clk_provide_backwards_compat(void)
 {
-	/* TODO */
+	enum did_reg_flags {
+		DID_REG_PSC	= BIT(0),
+		DID_REG_PSCFIFO	= BIT(1),
+		DID_REG_NFC	= BIT(2),
+		DID_REG_CAN	= BIT(3),
+		DID_REG_I2C	= BIT(4),
+		DID_REG_DIU	= BIT(5),
+		DID_REG_VIU	= BIT(6),
+		DID_REG_FEC	= BIT(7),
+		DID_REG_USB	= BIT(8),
+		DID_REG_PATA	= BIT(9),
+	};
+
+	int did_register;
+	struct device_node *np;
+	struct resource res;
+	int idx;
+	char devname[32];
+
+	/*
+	 * those macros are not exactly pretty, but they encapsulate a lot
+	 * of copy'n'paste heavy code which is even more ugly, and reduce
+	 * the potential for inconsistencies in those many code copies
+	 */
+
+#define FOR_NODES(compatname) \
+	for_each_compatible_node(np, NULL, compatname)
+
+#define NODE_PREP do { \
+	of_address_to_resource(np, 0, &res); \
+	snprintf(devname, sizeof(devname), "%08x.%s", res.start, np->name); \
+} while (0)
+
+#define NODE_CHK(clkname, clkitem, regnode, regflag) do { \
+	struct clk *clk; \
+	clk = of_clk_get_by_name(np, clkname); \
+	if (IS_ERR(clk)) { \
+		clk = clkitem; \
+		clk_register_clkdev(clk, clkname, devname); \
+		if (regnode) \
+			clk_register_clkdev(clk, clkname, np->name); \
+		did_register |= DID_REG_ ## regflag; \
+		pr_debug("clock alias name '%s' for dev '%s' pointer %p\n", \
+			 clkname, devname, clk); \
+	} else { \
+		clk_put(clk); \
+	} \
+} while (0)
+
+	did_register = 0;
+
+	FOR_NODES(mpc512x_select_psc_compat()) {
+		NODE_PREP;
+		idx = (res.start >> 8) & 0xf;
+		NODE_CHK("ipg", clks[MPC512x_CLK_PSC0 + idx], 0, PSC);
+		NODE_CHK("mclk", clks[MPC512x_CLK_PSC0_MCLK + idx], 0, PSC);
+	}
+
+	FOR_NODES("fsl,mpc5121-psc-fifo") {
+		NODE_PREP;
+		NODE_CHK("ipg", clks[MPC512x_CLK_PSC_FIFO], 1, PSCFIFO);
+	}
+
+	FOR_NODES("fsl,mpc5121-nfc") {
+		NODE_PREP;
+		NODE_CHK("ipg", clks[MPC512x_CLK_NFC], 0, NFC);
+	}
+
+	FOR_NODES("fsl,mpc5121-mscan") {
+		NODE_PREP;
+		idx = 0;
+		idx += (res.start & 0x2000) ? 2 : 0;
+		idx += (res.start & 0x0080) ? 1 : 0;
+		NODE_CHK("ipg", clks[MPC512x_CLK_BDLC], 0, CAN);
+		NODE_CHK("mclk", clks[MPC512x_CLK_MSCAN0_MCLK + idx], 0, CAN);
+	}
+
+	/*
+	 * do register the 'ips', 'sys', and 'ref' names globally
+	 * instead of inside each individual CAN node, as there is no
+	 * potential for a name conflict (in contrast to 'ipg' and 'mclk')
+	 */
+	if (did_register & DID_REG_CAN) {
+		clk_register_clkdev(clks[MPC512x_CLK_IPS], "ips", NULL);
+		clk_register_clkdev(clks[MPC512x_CLK_SYS], "sys", NULL);
+		clk_register_clkdev(clks[MPC512x_CLK_REF], "ref", NULL);
+	}
+
+	FOR_NODES("fsl,mpc5121-i2c") {
+		NODE_PREP;
+		NODE_CHK("ipg", clks[MPC512x_CLK_I2C], 0, I2C);
+	}
+
+	/*
+	 * workaround for the fact that the I2C driver does an "anonymous"
+	 * lookup (NULL name spec, which yields the first clock spec) for
+	 * which we cannot register an alias -- a _global_ 'ipg' alias that
+	 * is not bound to any device name and returns the I2C clock item
+	 * is not a good idea
+	 *
+	 * so we have the lookup in the peripheral driver fail, which is
+	 * silent and non-fatal, and pre-enable the clock item here such
+	 * that register access is possible
+	 *
+	 * see commit b3bfce2b "i2c: mpc: cleanup clock API use" for
+	 * details, adjusting s/NULL/"ipg"/ in i2c-mpc.c would make this
+	 * workaround obsolete
+	 */
+	if (did_register & DID_REG_I2C)
+		clk_prepare_enable(clks[MPC512x_CLK_I2C]);
+
+	FOR_NODES("fsl,mpc5121-diu") {
+		NODE_PREP;
+		NODE_CHK("ipg", clks[MPC512x_CLK_DIU], 1, DIU);
+	}
+
+	FOR_NODES("fsl,mpc5121-viu") {
+		NODE_PREP;
+		NODE_CHK("ipg", clks[MPC512x_CLK_VIU], 0, VIU);
+	}
+
+	/*
+	 * note that 2771399a "fs_enet: cleanup clock API use" did use the
+	 * "per" string for the clock lookup in contrast to the "ipg" name
+	 * which most other nodes are using -- this is not a fatal thing
+	 * but just something to keep in mind when doing compatibility
+	 * registration, it's a non-issue with up-to-date device tree data
+	 */
+	FOR_NODES("fsl,mpc5121-fec") {
+		NODE_PREP;
+		NODE_CHK("per", clks[MPC512x_CLK_FEC], 0, FEC);
+	}
+	FOR_NODES("fsl,mpc5121-fec-mdio") {
+		NODE_PREP;
+		NODE_CHK("per", clks[MPC512x_CLK_FEC], 0, FEC);
+	}
+
+	FOR_NODES("fsl,mpc5121-usb2-dr") {
+		NODE_PREP;
+		idx = (res.start & 0x4000) ? 1 : 0;
+		NODE_CHK("ipg", clks[MPC512x_CLK_USB1 + idx], 0, USB);
+	}
+
+	FOR_NODES("fsl,mpc5121-pata") {
+		NODE_PREP;
+		NODE_CHK("ipg", clks[MPC512x_CLK_PATA], 0, PATA);
+	}
+
+	/*
+	 * try to collapse diagnostics into a single line of output yet
+	 * provide a full list of what is missing, to avoid noise in the
+	 * absence of up-to-date device tree data -- backwards
+	 * compatibility to old DTBs is a requirement, updates may be
+	 * desirable or preferrable but are not at all mandatory
+	 */
+	if (did_register) {
+		pr_notice("device tree lacks clock specs, adding fallbacks (0x%x,%s%s%s%s%s%s%s%s%s%s)\n",
+			  did_register,
+			  (did_register & DID_REG_PSC) ? " PSC" : "",
+			  (did_register & DID_REG_PSCFIFO) ? " PSCFIFO" : "",
+			  (did_register & DID_REG_NFC) ? " NFC" : "",
+			  (did_register & DID_REG_CAN) ? " CAN" : "",
+			  (did_register & DID_REG_I2C) ? " I2C" : "",
+			  (did_register & DID_REG_DIU) ? " DIU" : "",
+			  (did_register & DID_REG_VIU) ? " VIU" : "",
+			  (did_register & DID_REG_FEC) ? " FEC" : "",
+			  (did_register & DID_REG_USB) ? " USB" : "",
+			  (did_register & DID_REG_PATA) ? " PATA" : "");
+	} else {
+		pr_debug("device tree has clock specs, no fallbacks added\n");
+	}
 }
 
 int __init mpc5121_clk_init(void)
-- 
1.7.10.4

[PATCH v5 06/17] dts: mpc512x: add clock specs for client lookups

[Gerhard Sittig]

this addresses the client side of device tree based clock lookups

add clock specifiers to the mbx, nfc, mscan, sdhc, i2c, axe, diu, viu,
mdio, fec, usb, pata, psc, psc fifo, and pci nodes in the shared
mpc5121.dtsi include

Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: devicetree@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Reviewed-by: Mike Turquette <mturquette@linaro.org>	# for v3: w/o bdlc, PSC ipg
Signed-off-by: Gerhard Sittig <gsi@denx.de>
---
 arch/powerpc/boot/dts/mpc5121.dtsi |   95 ++++++++++++++++++++++++++++++++++++
 1 file changed, 95 insertions(+)

diff --git a/arch/powerpc/boot/dts/mpc5121.dtsi b/arch/powerpc/boot/dts/mpc5121.dtsi
index 9bfcb7558197..d8c6f967785f 100644
--- a/arch/powerpc/boot/dts/mpc5121.dtsi
+++ b/arch/powerpc/boot/dts/mpc5121.dtsi
@@ -51,6 +51,10 @@
 		compatible = "fsl,mpc5121-mbx";
 		reg = <0x20000000 0x4000>;
 		interrupts = <66 0x8>;
+		clocks = <&clks MPC512x_CLK_MBX_BUS>,
+			 <&clks MPC512x_CLK_MBX_3D>,
+			 <&clks MPC512x_CLK_MBX>;
+		clock-names = "mbx-bus", "mbx-3d", "mbx";
 	};
 
 	sram@30000000 {
@@ -64,6 +68,8 @@
 		interrupts = <6 8>;
 		#address-cells = <1>;
 		#size-cells = <1>;
+		clocks = <&clks MPC512x_CLK_NFC>;
+		clock-names = "ipg";
 	};
 
 	localbus@80000020 {
@@ -156,12 +162,24 @@
 			compatible = "fsl,mpc5121-mscan";
 			reg = <0x1300 0x80>;
 			interrupts = <12 0x8>;
+			clocks = <&clks MPC512x_CLK_BDLC>,
+				 <&clks MPC512x_CLK_IPS>,
+				 <&clks MPC512x_CLK_SYS>,
+				 <&clks MPC512x_CLK_REF>,
+				 <&clks MPC512x_CLK_MSCAN0_MCLK>;
+			clock-names = "ipg", "ips", "sys", "ref", "mclk";
 		};
 
 		can@1380 {
 			compatible = "fsl,mpc5121-mscan";
 			reg = <0x1380 0x80>;
 			interrupts = <13 0x8>;
+			clocks = <&clks MPC512x_CLK_BDLC>,
+				 <&clks MPC512x_CLK_IPS>,
+				 <&clks MPC512x_CLK_SYS>,
+				 <&clks MPC512x_CLK_REF>,
+				 <&clks MPC512x_CLK_MSCAN1_MCLK>;
+			clock-names = "ipg", "ips", "sys", "ref", "mclk";
 		};
 
 		sdhc@1500 {
@@ -170,6 +188,9 @@
 			interrupts = <8 0x8>;
 			dmas = <&dma0 30>;
 			dma-names = "rx-tx";
+			clocks = <&clks MPC512x_CLK_IPS>,
+				 <&clks MPC512x_CLK_SDHC>;
+			clock-names = "ipg", "per";
 		};
 
 		i2c@1700 {
@@ -178,6 +199,8 @@
 			compatible = "fsl,mpc5121-i2c", "fsl-i2c";
 			reg = <0x1700 0x20>;
 			interrupts = <9 0x8>;
+			clocks = <&clks MPC512x_CLK_I2C>;
+			clock-names = "ipg";
 		};
 
 		i2c@1720 {
@@ -186,6 +209,8 @@
 			compatible = "fsl,mpc5121-i2c", "fsl-i2c";
 			reg = <0x1720 0x20>;
 			interrupts = <10 0x8>;
+			clocks = <&clks MPC512x_CLK_I2C>;
+			clock-names = "ipg";
 		};
 
 		i2c@1740 {
@@ -194,6 +219,8 @@
 			compatible = "fsl,mpc5121-i2c", "fsl-i2c";
 			reg = <0x1740 0x20>;
 			interrupts = <11 0x8>;
+			clocks = <&clks MPC512x_CLK_I2C>;
+			clock-names = "ipg";
 		};
 
 		i2ccontrol@1760 {
@@ -205,30 +232,48 @@
 			compatible = "fsl,mpc5121-axe";
 			reg = <0x2000 0x100>;
 			interrupts = <42 0x8>;
+			clocks = <&clks MPC512x_CLK_AXE>;
+			clock-names = "ipg";
 		};
 
 		display@2100 {
 			compatible = "fsl,mpc5121-diu";
 			reg = <0x2100 0x100>;
 			interrupts = <64 0x8>;
+			clocks = <&clks MPC512x_CLK_DIU>;
+			clock-names = "ipg";
 		};
 
 		can@2300 {
 			compatible = "fsl,mpc5121-mscan";
 			reg = <0x2300 0x80>;
 			interrupts = <90 0x8>;
+			clocks = <&clks MPC512x_CLK_BDLC>,
+				 <&clks MPC512x_CLK_IPS>,
+				 <&clks MPC512x_CLK_SYS>,
+				 <&clks MPC512x_CLK_REF>,
+				 <&clks MPC512x_CLK_MSCAN2_MCLK>;
+			clock-names = "ipg", "ips", "sys", "ref", "mclk";
 		};
 
 		can@2380 {
 			compatible = "fsl,mpc5121-mscan";
 			reg = <0x2380 0x80>;
 			interrupts = <91 0x8>;
+			clocks = <&clks MPC512x_CLK_BDLC>,
+				 <&clks MPC512x_CLK_IPS>,
+				 <&clks MPC512x_CLK_SYS>,
+				 <&clks MPC512x_CLK_REF>,
+				 <&clks MPC512x_CLK_MSCAN3_MCLK>;
+			clock-names = "ipg", "ips", "sys", "ref", "mclk";
 		};
 
 		viu@2400 {
 			compatible = "fsl,mpc5121-viu";
 			reg = <0x2400 0x400>;
 			interrupts = <67 0x8>;
+			clocks = <&clks MPC512x_CLK_VIU>;
+			clock-names = "ipg";
 		};
 
 		mdio@2800 {
@@ -236,6 +281,8 @@
 			reg = <0x2800 0x800>;
 			#address-cells = <1>;
 			#size-cells = <0>;
+			clocks = <&clks MPC512x_CLK_FEC>;
+			clock-names = "per";
 		};
 
 		eth0: ethernet@2800 {
@@ -244,6 +291,8 @@
 			reg = <0x2800 0x800>;
 			local-mac-address = [ 00 00 00 00 00 00 ];
 			interrupts = <4 0x8>;
+			clocks = <&clks MPC512x_CLK_FEC>;
+			clock-names = "per";
 		};
 
 		/* USB1 using external ULPI PHY */
@@ -255,6 +304,8 @@
 			interrupts = <43 0x8>;
 			dr_mode = "otg";
 			phy_type = "ulpi";
+			clocks = <&clks MPC512x_CLK_USB1>;
+			clock-names = "ipg";
 		};
 
 		/* USB0 using internal UTMI PHY */
@@ -266,6 +317,8 @@
 			interrupts = <44 0x8>;
 			dr_mode = "otg";
 			phy_type = "utmi_wide";
+			clocks = <&clks MPC512x_CLK_USB2>;
+			clock-names = "ipg";
 		};
 
 		/* IO control */
@@ -284,6 +337,8 @@
 			compatible = "fsl,mpc5121-pata";
 			reg = <0x10200 0x100>;
 			interrupts = <5 0x8>;
+			clocks = <&clks MPC512x_CLK_PATA>;
+			clock-names = "ipg";
 		};
 
 		/* 512x PSCs are not 52xx PSC compatible */
@@ -295,6 +350,9 @@
 			interrupts = <40 0x8>;
 			fsl,rx-fifo-size = <16>;
 			fsl,tx-fifo-size = <16>;
+			clocks = <&clks MPC512x_CLK_PSC0>,
+				 <&clks MPC512x_CLK_PSC0_MCLK>;
+			clock-names = "ipg", "mclk";
 		};
 
 		/* PSC1 */
@@ -304,6 +362,9 @@
 			interrupts = <40 0x8>;
 			fsl,rx-fifo-size = <16>;
 			fsl,tx-fifo-size = <16>;
+			clocks = <&clks MPC512x_CLK_PSC1>,
+				 <&clks MPC512x_CLK_PSC1_MCLK>;
+			clock-names = "ipg", "mclk";
 		};
 
 		/* PSC2 */
@@ -313,6 +374,9 @@
 			interrupts = <40 0x8>;
 			fsl,rx-fifo-size = <16>;
 			fsl,tx-fifo-size = <16>;
+			clocks = <&clks MPC512x_CLK_PSC2>,
+				 <&clks MPC512x_CLK_PSC2_MCLK>;
+			clock-names = "ipg", "mclk";
 		};
 
 		/* PSC3 */
@@ -322,6 +386,9 @@
 			interrupts = <40 0x8>;
 			fsl,rx-fifo-size = <16>;
 			fsl,tx-fifo-size = <16>;
+			clocks = <&clks MPC512x_CLK_PSC3>,
+				 <&clks MPC512x_CLK_PSC3_MCLK>;
+			clock-names = "ipg", "mclk";
 		};
 
 		/* PSC4 */
@@ -331,6 +398,9 @@
 			interrupts = <40 0x8>;
 			fsl,rx-fifo-size = <16>;
 			fsl,tx-fifo-size = <16>;
+			clocks = <&clks MPC512x_CLK_PSC4>,
+				 <&clks MPC512x_CLK_PSC4_MCLK>;
+			clock-names = "ipg", "mclk";
 		};
 
 		/* PSC5 */
@@ -340,6 +410,9 @@
 			interrupts = <40 0x8>;
 			fsl,rx-fifo-size = <16>;
 			fsl,tx-fifo-size = <16>;
+			clocks = <&clks MPC512x_CLK_PSC5>,
+				 <&clks MPC512x_CLK_PSC5_MCLK>;
+			clock-names = "ipg", "mclk";
 		};
 
 		/* PSC6 */
@@ -349,6 +422,9 @@
 			interrupts = <40 0x8>;
 			fsl,rx-fifo-size = <16>;
 			fsl,tx-fifo-size = <16>;
+			clocks = <&clks MPC512x_CLK_PSC6>,
+				 <&clks MPC512x_CLK_PSC6_MCLK>;
+			clock-names = "ipg", "mclk";
 		};
 
 		/* PSC7 */
@@ -358,6 +434,9 @@
 			interrupts = <40 0x8>;
 			fsl,rx-fifo-size = <16>;
 			fsl,tx-fifo-size = <16>;
+			clocks = <&clks MPC512x_CLK_PSC7>,
+				 <&clks MPC512x_CLK_PSC7_MCLK>;
+			clock-names = "ipg", "mclk";
 		};
 
 		/* PSC8 */
@@ -367,6 +446,9 @@
 			interrupts = <40 0x8>;
 			fsl,rx-fifo-size = <16>;
 			fsl,tx-fifo-size = <16>;
+			clocks = <&clks MPC512x_CLK_PSC8>,
+				 <&clks MPC512x_CLK_PSC8_MCLK>;
+			clock-names = "ipg", "mclk";
 		};
 
 		/* PSC9 */
@@ -376,6 +458,9 @@
 			interrupts = <40 0x8>;
 			fsl,rx-fifo-size = <16>;
 			fsl,tx-fifo-size = <16>;
+			clocks = <&clks MPC512x_CLK_PSC9>,
+				 <&clks MPC512x_CLK_PSC9_MCLK>;
+			clock-names = "ipg", "mclk";
 		};
 
 		/* PSC10 */
@@ -385,6 +470,9 @@
 			interrupts = <40 0x8>;
 			fsl,rx-fifo-size = <16>;
 			fsl,tx-fifo-size = <16>;
+			clocks = <&clks MPC512x_CLK_PSC10>,
+				 <&clks MPC512x_CLK_PSC10_MCLK>;
+			clock-names = "ipg", "mclk";
 		};
 
 		/* PSC11 */
@@ -394,12 +482,17 @@
 			interrupts = <40 0x8>;
 			fsl,rx-fifo-size = <16>;
 			fsl,tx-fifo-size = <16>;
+			clocks = <&clks MPC512x_CLK_PSC11>,
+				 <&clks MPC512x_CLK_PSC11_MCLK>;
+			clock-names = "ipg", "mclk";
 		};
 
 		pscfifo@11f00 {
 			compatible = "fsl,mpc5121-psc-fifo";
 			reg = <0x11f00 0x100>;
 			interrupts = <40 0x8>;
+			clocks = <&clks MPC512x_CLK_PSC_FIFO>;
+			clock-names = "ipg";
 		};
 
 		dma0: dma@14000 {
@@ -417,6 +510,8 @@
 		#address-cells = <3>;
 		#size-cells = <2>;
 		#interrupt-cells = <1>;
+		clocks = <&clks MPC512x_CLK_PCI>;
+		clock-names = "ipg";
 
 		reg = <0x80008500 0x100	/* internal registers */
 		       0x80008300 0x8>;	/* config space access registers */
-- 
1.7.10.4

[PATCH v5 07/17] clk: mpc5xxx: switch to COMMON_CLK, retire PPC_CLOCK

[Gerhard Sittig]

the setup before the change was
- arch/powerpc/Kconfig had the PPC_CLOCK option, off by default
- depending on the PPC_CLOCK option the arch/powerpc/kernel/clock.c file
  was built, which implements the clk.h API but always returns -ENOSYS
  unless a platform registers specific callbacks
- the MPC52xx platform selected PPC_CLOCK but did not register any
  callbacks, thus all clk.h API calls keep resulting in -ENOSYS errors
  (which is OK, all peripheral drivers deal with the situation)
- the MPC512x platform selected PPC_CLOCK and registered specific
  callbacks implemented in arch/powerpc/platforms/512x/clock.c, thus
  provided real support for the clock API
- no other powerpc platform did select PPC_CLOCK

the situation after the change is
- the MPC512x platform implements the COMMON_CLK interface, and thus the
  PPC_CLOCK approach in arch/powerpc/platforms/512x/clock.c has become
  obsolete
- the MPC52xx platform still lacks genuine support for the clk.h API
  while this is not a change against the previous situation (the error
  code returned from COMMON_CLK stubs differs but every call still
  results in an error)
- with all references gone, the arch/powerpc/kernel/clock.c wrapper and
  the PPC_CLOCK option have become obsolete

the switch from PPC_CLOCK to COMMON_CLK is done for all platforms within
the same commit such that multiplatform kernels (the combination of 512x
and 52xx within one executable) keep working

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>
---
 arch/powerpc/Kconfig                 |    5 -
 arch/powerpc/kernel/Makefile         |    1 -
 arch/powerpc/kernel/clock.c          |   82 ----
 arch/powerpc/platforms/512x/Kconfig  |    2 +-
 arch/powerpc/platforms/512x/Makefile |    1 -
 arch/powerpc/platforms/512x/clock.c  |  753 ----------------------------------
 arch/powerpc/platforms/52xx/Kconfig  |    2 +-
 7 files changed, 2 insertions(+), 844 deletions(-)
 delete mode 100644 arch/powerpc/kernel/clock.c
 delete mode 100644 arch/powerpc/platforms/512x/clock.c

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 38f3b7e47ec5..ccf5132e61e7 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -1030,11 +1030,6 @@ config KEYS_COMPAT
 
 source "crypto/Kconfig"
 
-config PPC_CLOCK
-	bool
-	default n
-	select HAVE_CLK
-
 config PPC_LIB_RHEAP
 	bool
 
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 445cb6e39d5b..f460a3b769dc 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -47,7 +47,6 @@ obj-$(CONFIG_ALTIVEC)		+= vecemu.o
 obj-$(CONFIG_PPC_970_NAP)	+= idle_power4.o
 obj-$(CONFIG_PPC_P7_NAP)	+= idle_power7.o
 obj-$(CONFIG_PPC_OF)		+= of_platform.o prom_parse.o
-obj-$(CONFIG_PPC_CLOCK)		+= clock.o
 procfs-y			:= proc_powerpc.o
 obj-$(CONFIG_PROC_FS)		+= $(procfs-y)
 rtaspci-$(CONFIG_PPC64)-$(CONFIG_PCI)	:= rtas_pci.o
diff --git a/arch/powerpc/kernel/clock.c b/arch/powerpc/kernel/clock.c
deleted file mode 100644
index a764b47791e8..000000000000
--- a/arch/powerpc/kernel/clock.c
+++ /dev/null
@@ -1,82 +0,0 @@
-/*
- * Dummy clk implementations for powerpc.
- * These need to be overridden in platform code.
- */
-
-#include <linux/clk.h>
-#include <linux/err.h>
-#include <linux/errno.h>
-#include <linux/export.h>
-#include <asm/clk_interface.h>
-
-struct clk_interface clk_functions;
-
-struct clk *clk_get(struct device *dev, const char *id)
-{
-	if (clk_functions.clk_get)
-		return clk_functions.clk_get(dev, id);
-	return ERR_PTR(-ENOSYS);
-}
-EXPORT_SYMBOL(clk_get);
-
-void clk_put(struct clk *clk)
-{
-	if (clk_functions.clk_put)
-		clk_functions.clk_put(clk);
-}
-EXPORT_SYMBOL(clk_put);
-
-int clk_enable(struct clk *clk)
-{
-	if (clk_functions.clk_enable)
-		return clk_functions.clk_enable(clk);
-	return -ENOSYS;
-}
-EXPORT_SYMBOL(clk_enable);
-
-void clk_disable(struct clk *clk)
-{
-	if (clk_functions.clk_disable)
-		clk_functions.clk_disable(clk);
-}
-EXPORT_SYMBOL(clk_disable);
-
-unsigned long clk_get_rate(struct clk *clk)
-{
-	if (clk_functions.clk_get_rate)
-		return clk_functions.clk_get_rate(clk);
-	return 0;
-}
-EXPORT_SYMBOL(clk_get_rate);
-
-long clk_round_rate(struct clk *clk, unsigned long rate)
-{
-	if (clk_functions.clk_round_rate)
-		return clk_functions.clk_round_rate(clk, rate);
-	return -ENOSYS;
-}
-EXPORT_SYMBOL(clk_round_rate);
-
-int clk_set_rate(struct clk *clk, unsigned long rate)
-{
-	if (clk_functions.clk_set_rate)
-		return clk_functions.clk_set_rate(clk, rate);
-	return -ENOSYS;
-}
-EXPORT_SYMBOL(clk_set_rate);
-
-struct clk *clk_get_parent(struct clk *clk)
-{
-	if (clk_functions.clk_get_parent)
-		return clk_functions.clk_get_parent(clk);
-	return ERR_PTR(-ENOSYS);
-}
-EXPORT_SYMBOL(clk_get_parent);
-
-int clk_set_parent(struct clk *clk, struct clk *parent)
-{
-	if (clk_functions.clk_set_parent)
-		return clk_functions.clk_set_parent(clk, parent);
-	return -ENOSYS;
-}
-EXPORT_SYMBOL(clk_set_parent);
diff --git a/arch/powerpc/platforms/512x/Kconfig b/arch/powerpc/platforms/512x/Kconfig
index fc9c1cbfcb1d..5aa3f4b5332c 100644
--- a/arch/powerpc/platforms/512x/Kconfig
+++ b/arch/powerpc/platforms/512x/Kconfig
@@ -1,9 +1,9 @@
 config PPC_MPC512x
 	bool "512x-based boards"
 	depends on 6xx
+	select COMMON_CLK
 	select FSL_SOC
 	select IPIC
-	select PPC_CLOCK
 	select PPC_PCI_CHOICE
 	select FSL_PCI if PCI
 	select ARCH_WANT_OPTIONAL_GPIOLIB
diff --git a/arch/powerpc/platforms/512x/Makefile b/arch/powerpc/platforms/512x/Makefile
index 1e05f9def8a4..01693121a2b1 100644
--- a/arch/powerpc/platforms/512x/Makefile
+++ b/arch/powerpc/platforms/512x/Makefile
@@ -1,7 +1,6 @@
 #
 # Makefile for the Freescale PowerPC 512x linux kernel.
 #
-obj-$(CONFIG_PPC_CLOCK)		+= clock.o
 obj-$(CONFIG_COMMON_CLK)	+= clock-commonclk.o
 obj-y				+= mpc512x_shared.o
 obj-$(CONFIG_MPC5121_ADS)	+= mpc5121_ads.o mpc5121_ads_cpld.o
diff --git a/arch/powerpc/platforms/512x/clock.c b/arch/powerpc/platforms/512x/clock.c
deleted file mode 100644
index e504166e089a..000000000000
--- a/arch/powerpc/platforms/512x/clock.c
+++ /dev/null
@@ -1,753 +0,0 @@
-/*
- * Copyright (C) 2007,2008 Freescale Semiconductor, Inc. All rights reserved.
- *
- * Author: John Rigby <jrigby@freescale.com>
- *
- * Implements the clk api defined in include/linux/clk.h
- *
- *    Original based on linux/arch/arm/mach-integrator/clock.c
- *
- *    Copyright (C) 2004 ARM Limited.
- *    Written by Deep Blue Solutions Limited.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-#include <linux/kernel.h>
-#include <linux/list.h>
-#include <linux/errno.h>
-#include <linux/err.h>
-#include <linux/module.h>
-#include <linux/string.h>
-#include <linux/clk.h>
-#include <linux/mutex.h>
-#include <linux/io.h>
-
-#include <linux/of_platform.h>
-#include <asm/mpc5xxx.h>
-#include <asm/mpc5121.h>
-#include <asm/clk_interface.h>
-
-#include "mpc512x.h"
-
-#undef CLK_DEBUG
-
-static int clocks_initialized;
-
-#define CLK_HAS_RATE	0x1	/* has rate in MHz */
-#define CLK_HAS_CTRL	0x2	/* has control reg and bit */
-
-struct clk {
-	struct list_head node;
-	char name[32];
-	int flags;
-	struct device *dev;
-	unsigned long rate;
-	struct module *owner;
-	void (*calc) (struct clk *);
-	struct clk *parent;
-	int reg, bit;		/* CLK_HAS_CTRL */
-	int div_shift;		/* only used by generic_div_clk_calc */
-};
-
-static LIST_HEAD(clocks);
-static DEFINE_MUTEX(clocks_mutex);
-
-static struct clk *mpc5121_clk_get(struct device *dev, const char *id)
-{
-	struct clk *p, *clk = ERR_PTR(-ENOENT);
-	int dev_match;
-	int id_match;
-
-	if (dev == NULL || id == NULL)
-		return clk;
-
-	mutex_lock(&clocks_mutex);
-	list_for_each_entry(p, &clocks, node) {
-		dev_match = id_match = 0;
-
-		if (dev == p->dev)
-			dev_match++;
-		if (strcmp(id, p->name) == 0)
-			id_match++;
-		if ((dev_match || id_match) && try_module_get(p->owner)) {
-			clk = p;
-			break;
-		}
-	}
-	mutex_unlock(&clocks_mutex);
-
-	return clk;
-}
-
-#ifdef CLK_DEBUG
-static void dump_clocks(void)
-{
-	struct clk *p;
-
-	mutex_lock(&clocks_mutex);
-	printk(KERN_INFO "CLOCKS:\n");
-	list_for_each_entry(p, &clocks, node) {
-		pr_info("  %s=%ld", p->name, p->rate);
-		if (p->parent)
-			pr_cont(" %s=%ld", p->parent->name,
-			       p->parent->rate);
-		if (p->flags & CLK_HAS_CTRL)
-			pr_cont(" reg/bit=%d/%d", p->reg, p->bit);
-		pr_cont("\n");
-	}
-	mutex_unlock(&clocks_mutex);
-}
-#define	DEBUG_CLK_DUMP() dump_clocks()
-#else
-#define	DEBUG_CLK_DUMP()
-#endif
-
-
-static void mpc5121_clk_put(struct clk *clk)
-{
-	module_put(clk->owner);
-}
-
-#define NRPSC 12
-
-struct mpc512x_clockctl {
-	u32 spmr;		/* System PLL Mode Reg */
-	u32 sccr[2];		/* System Clk Ctrl Reg 1 & 2 */
-	u32 scfr1;		/* System Clk Freq Reg 1 */
-	u32 scfr2;		/* System Clk Freq Reg 2 */
-	u32 reserved;
-	u32 bcr;		/* Bread Crumb Reg */
-	u32 pccr[NRPSC];	/* PSC Clk Ctrl Reg 0-11 */
-	u32 spccr;		/* SPDIF Clk Ctrl Reg */
-	u32 cccr;		/* CFM Clk Ctrl Reg */
-	u32 dccr;		/* DIU Clk Cnfg Reg */
-};
-
-static struct mpc512x_clockctl __iomem *clockctl;
-
-static int mpc5121_clk_enable(struct clk *clk)
-{
-	unsigned int mask;
-
-	if (clk->flags & CLK_HAS_CTRL) {
-		mask = in_be32(&clockctl->sccr[clk->reg]);
-		mask |= 1 << clk->bit;
-		out_be32(&clockctl->sccr[clk->reg], mask);
-	}
-	return 0;
-}
-
-static void mpc5121_clk_disable(struct clk *clk)
-{
-	unsigned int mask;
-
-	if (clk->flags & CLK_HAS_CTRL) {
-		mask = in_be32(&clockctl->sccr[clk->reg]);
-		mask &= ~(1 << clk->bit);
-		out_be32(&clockctl->sccr[clk->reg], mask);
-	}
-}
-
-static unsigned long mpc5121_clk_get_rate(struct clk *clk)
-{
-	if (clk->flags & CLK_HAS_RATE)
-		return clk->rate;
-	else
-		return 0;
-}
-
-static long mpc5121_clk_round_rate(struct clk *clk, unsigned long rate)
-{
-	return rate;
-}
-
-static int mpc5121_clk_set_rate(struct clk *clk, unsigned long rate)
-{
-	return 0;
-}
-
-static int clk_register(struct clk *clk)
-{
-	mutex_lock(&clocks_mutex);
-	list_add(&clk->node, &clocks);
-	mutex_unlock(&clocks_mutex);
-	return 0;
-}
-
-static unsigned long spmf_mult(void)
-{
-	/*
-	 * Convert spmf to multiplier
-	 */
-	static int spmf_to_mult[] = {
-		68, 1, 12, 16,
-		20, 24, 28, 32,
-		36, 40, 44, 48,
-		52, 56, 60, 64
-	};
-	int spmf = (in_be32(&clockctl->spmr) >> 24) & 0xf;
-	return spmf_to_mult[spmf];
-}
-
-static unsigned long sysdiv_div_x_2(void)
-{
-	/*
-	 * Convert sysdiv to divisor x 2
-	 * Some divisors have fractional parts so
-	 * multiply by 2 then divide by this value
-	 */
-	static int sysdiv_to_div_x_2[] = {
-		4, 5, 6, 7,
-		8, 9, 10, 14,
-		12, 16, 18, 22,
-		20, 24, 26, 30,
-		28, 32, 34, 38,
-		36, 40, 42, 46,
-		44, 48, 50, 54,
-		52, 56, 58, 62,
-		60, 64, 66,
-	};
-	int sysdiv = (in_be32(&clockctl->scfr2) >> 26) & 0x3f;
-	return sysdiv_to_div_x_2[sysdiv];
-}
-
-static unsigned long ref_to_sys(unsigned long rate)
-{
-	rate *= spmf_mult();
-	rate *= 2;
-	rate /= sysdiv_div_x_2();
-
-	return rate;
-}
-
-static unsigned long sys_to_ref(unsigned long rate)
-{
-	rate *= sysdiv_div_x_2();
-	rate /= 2;
-	rate /= spmf_mult();
-
-	return rate;
-}
-
-static long ips_to_ref(unsigned long rate)
-{
-	int ips_div = (in_be32(&clockctl->scfr1) >> 23) & 0x7;
-
-	rate *= ips_div;	/* csb_clk = ips_clk * ips_div */
-	rate *= 2;		/* sys_clk = csb_clk * 2 */
-	return sys_to_ref(rate);
-}
-
-static unsigned long devtree_getfreq(char *clockname)
-{
-	struct device_node *np;
-	const unsigned int *prop;
-	unsigned int val = 0;
-
-	np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-immr");
-	if (np) {
-		prop = of_get_property(np, clockname, NULL);
-		if (prop)
-			val = *prop;
-	    of_node_put(np);
-	}
-	return val;
-}
-
-static void ref_clk_calc(struct clk *clk)
-{
-	unsigned long rate;
-
-	rate = devtree_getfreq("bus-frequency");
-	if (rate == 0) {
-		printk(KERN_ERR "No bus-frequency in dev tree\n");
-		clk->rate = 0;
-		return;
-	}
-	clk->rate = ips_to_ref(rate);
-}
-
-static struct clk ref_clk = {
-	.name = "ref_clk",
-	.calc = ref_clk_calc,
-};
-
-
-static void sys_clk_calc(struct clk *clk)
-{
-	clk->rate = ref_to_sys(ref_clk.rate);
-}
-
-static struct clk sys_clk = {
-	.name = "sys_clk",
-	.calc = sys_clk_calc,
-};
-
-static void diu_clk_calc(struct clk *clk)
-{
-	int diudiv_x_2 = in_be32(&clockctl->scfr1) & 0xff;
-	unsigned long rate;
-
-	rate = sys_clk.rate;
-
-	rate *= 2;
-	rate /= diudiv_x_2;
-
-	clk->rate = rate;
-}
-
-static void viu_clk_calc(struct clk *clk)
-{
-	unsigned long rate;
-
-	rate = sys_clk.rate;
-	rate /= 2;
-	clk->rate = rate;
-}
-
-static void half_clk_calc(struct clk *clk)
-{
-	clk->rate = clk->parent->rate / 2;
-}
-
-static void generic_div_clk_calc(struct clk *clk)
-{
-	int div = (in_be32(&clockctl->scfr1) >> clk->div_shift) & 0x7;
-
-	clk->rate = clk->parent->rate / div;
-}
-
-static void unity_clk_calc(struct clk *clk)
-{
-	clk->rate = clk->parent->rate;
-}
-
-static struct clk csb_clk = {
-	.name = "csb_clk",
-	.calc = half_clk_calc,
-	.parent = &sys_clk,
-};
-
-static void e300_clk_calc(struct clk *clk)
-{
-	int spmf = (in_be32(&clockctl->spmr) >> 16) & 0xf;
-	int ratex2 = clk->parent->rate * spmf;
-
-	clk->rate = ratex2 / 2;
-}
-
-static struct clk e300_clk = {
-	.name = "e300_clk",
-	.calc = e300_clk_calc,
-	.parent = &csb_clk,
-};
-
-static struct clk ips_clk = {
-	.name = "ips_clk",
-	.calc = generic_div_clk_calc,
-	.parent = &csb_clk,
-	.div_shift = 23,
-};
-
-/*
- * Clocks controlled by SCCR1 (.reg = 0)
- */
-static struct clk lpc_clk = {
-	.name = "lpc_clk",
-	.flags = CLK_HAS_CTRL,
-	.reg = 0,
-	.bit = 30,
-	.calc = generic_div_clk_calc,
-	.parent = &ips_clk,
-	.div_shift = 11,
-};
-
-static struct clk nfc_clk = {
-	.name = "nfc_clk",
-	.flags = CLK_HAS_CTRL,
-	.reg = 0,
-	.bit = 29,
-	.calc = generic_div_clk_calc,
-	.parent = &ips_clk,
-	.div_shift = 8,
-};
-
-static struct clk pata_clk = {
-	.name = "pata_clk",
-	.flags = CLK_HAS_CTRL,
-	.reg = 0,
-	.bit = 28,
-	.calc = unity_clk_calc,
-	.parent = &ips_clk,
-};
-
-/*
- * PSC clocks (bits 27 - 16)
- * are setup elsewhere
- */
-
-static struct clk sata_clk = {
-	.name = "sata_clk",
-	.flags = CLK_HAS_CTRL,
-	.reg = 0,
-	.bit = 14,
-	.calc = unity_clk_calc,
-	.parent = &ips_clk,
-};
-
-static struct clk fec_clk = {
-	.name = "fec_clk",
-	.flags = CLK_HAS_CTRL,
-	.reg = 0,
-	.bit = 13,
-	.calc = unity_clk_calc,
-	.parent = &ips_clk,
-};
-
-static struct clk pci_clk = {
-	.name = "pci_clk",
-	.flags = CLK_HAS_CTRL,
-	.reg = 0,
-	.bit = 11,
-	.calc = generic_div_clk_calc,
-	.parent = &csb_clk,
-	.div_shift = 20,
-};
-
-/*
- * Clocks controlled by SCCR2 (.reg = 1)
- */
-static struct clk diu_clk = {
-	.name = "diu_clk",
-	.flags = CLK_HAS_CTRL,
-	.reg = 1,
-	.bit = 31,
-	.calc = diu_clk_calc,
-};
-
-static struct clk viu_clk = {
-	.name = "viu_clk",
-	.flags = CLK_HAS_CTRL,
-	.reg = 1,
-	.bit = 18,
-	.calc = viu_clk_calc,
-};
-
-static struct clk axe_clk = {
-	.name = "axe_clk",
-	.flags = CLK_HAS_CTRL,
-	.reg = 1,
-	.bit = 30,
-	.calc = unity_clk_calc,
-	.parent = &csb_clk,
-};
-
-static struct clk usb1_clk = {
-	.name = "usb1_clk",
-	.flags = CLK_HAS_CTRL,
-	.reg = 1,
-	.bit = 28,
-	.calc = unity_clk_calc,
-	.parent = &csb_clk,
-};
-
-static struct clk usb2_clk = {
-	.name = "usb2_clk",
-	.flags = CLK_HAS_CTRL,
-	.reg = 1,
-	.bit = 27,
-	.calc = unity_clk_calc,
-	.parent = &csb_clk,
-};
-
-static struct clk i2c_clk = {
-	.name = "i2c_clk",
-	.flags = CLK_HAS_CTRL,
-	.reg = 1,
-	.bit = 26,
-	.calc = unity_clk_calc,
-	.parent = &ips_clk,
-};
-
-static struct clk mscan_clk = {
-	.name = "mscan_clk",
-	.flags = CLK_HAS_CTRL,
-	.reg = 1,
-	.bit = 25,
-	.calc = unity_clk_calc,
-	.parent = &ips_clk,
-};
-
-static struct clk sdhc_clk = {
-	.name = "sdhc_clk",
-	.flags = CLK_HAS_CTRL,
-	.reg = 1,
-	.bit = 24,
-	.calc = unity_clk_calc,
-	.parent = &ips_clk,
-};
-
-static struct clk mbx_bus_clk = {
-	.name = "mbx_bus_clk",
-	.flags = CLK_HAS_CTRL,
-	.reg = 1,
-	.bit = 22,
-	.calc = half_clk_calc,
-	.parent = &csb_clk,
-};
-
-static struct clk mbx_clk = {
-	.name = "mbx_clk",
-	.flags = CLK_HAS_CTRL,
-	.reg = 1,
-	.bit = 21,
-	.calc = unity_clk_calc,
-	.parent = &csb_clk,
-};
-
-static struct clk mbx_3d_clk = {
-	.name = "mbx_3d_clk",
-	.flags = CLK_HAS_CTRL,
-	.reg = 1,
-	.bit = 20,
-	.calc = generic_div_clk_calc,
-	.parent = &mbx_bus_clk,
-	.div_shift = 14,
-};
-
-static void psc_mclk_in_calc(struct clk *clk)
-{
-	clk->rate = devtree_getfreq("psc_mclk_in");
-	if (!clk->rate)
-		clk->rate = 25000000;
-}
-
-static struct clk psc_mclk_in = {
-	.name = "psc_mclk_in",
-	.calc = psc_mclk_in_calc,
-};
-
-static struct clk spdif_txclk = {
-	.name = "spdif_txclk",
-	.flags = CLK_HAS_CTRL,
-	.reg = 1,
-	.bit = 23,
-};
-
-static struct clk spdif_rxclk = {
-	.name = "spdif_rxclk",
-	.flags = CLK_HAS_CTRL,
-	.reg = 1,
-	.bit = 23,
-};
-
-static void ac97_clk_calc(struct clk *clk)
-{
-	/* ac97 bit clock is always 24.567 MHz */
-	clk->rate = 24567000;
-}
-
-static struct clk ac97_clk = {
-	.name = "ac97_clk_in",
-	.calc = ac97_clk_calc,
-};
-
-static struct clk *rate_clks[] = {
-	&ref_clk,
-	&sys_clk,
-	&diu_clk,
-	&viu_clk,
-	&csb_clk,
-	&e300_clk,
-	&ips_clk,
-	&fec_clk,
-	&sata_clk,
-	&pata_clk,
-	&nfc_clk,
-	&lpc_clk,
-	&mbx_bus_clk,
-	&mbx_clk,
-	&mbx_3d_clk,
-	&axe_clk,
-	&usb1_clk,
-	&usb2_clk,
-	&i2c_clk,
-	&mscan_clk,
-	&sdhc_clk,
-	&pci_clk,
-	&psc_mclk_in,
-	&spdif_txclk,
-	&spdif_rxclk,
-	&ac97_clk,
-	NULL
-};
-
-static void rate_clk_init(struct clk *clk)
-{
-	if (clk->calc) {
-		clk->calc(clk);
-		clk->flags |= CLK_HAS_RATE;
-		clk_register(clk);
-	} else {
-		printk(KERN_WARNING
-		       "Could not initialize clk %s without a calc routine\n",
-		       clk->name);
-	}
-}
-
-static void rate_clks_init(void)
-{
-	struct clk **cpp, *clk;
-
-	cpp = rate_clks;
-	while ((clk = *cpp++))
-		rate_clk_init(clk);
-}
-
-/*
- * There are two clk enable registers with 32 enable bits each
- * psc clocks and device clocks are all stored in dev_clks
- */
-static struct clk dev_clks[2][32];
-
-/*
- * Given a psc number return the dev_clk
- * associated with it
- */
-static struct clk *psc_dev_clk(int pscnum)
-{
-	int reg, bit;
-	struct clk *clk;
-
-	reg = 0;
-	bit = 27 - pscnum;
-
-	clk = &dev_clks[reg][bit];
-	clk->reg = 0;
-	clk->bit = bit;
-	return clk;
-}
-
-/*
- * PSC clock rate calculation
- */
-static void psc_calc_rate(struct clk *clk, int pscnum, struct device_node *np)
-{
-	unsigned long mclk_src = sys_clk.rate;
-	unsigned long mclk_div;
-
-	/*
-	 * Can only change value of mclk divider
-	 * when the divider is disabled.
-	 *
-	 * Zero is not a valid divider so minimum
-	 * divider is 1
-	 *
-	 * disable/set divider/enable
-	 */
-	out_be32(&clockctl->pccr[pscnum], 0);
-	out_be32(&clockctl->pccr[pscnum], 0x00020000);
-	out_be32(&clockctl->pccr[pscnum], 0x00030000);
-
-	if (in_be32(&clockctl->pccr[pscnum]) & 0x80) {
-		clk->rate = spdif_rxclk.rate;
-		return;
-	}
-
-	switch ((in_be32(&clockctl->pccr[pscnum]) >> 14) & 0x3) {
-	case 0:
-		mclk_src = sys_clk.rate;
-		break;
-	case 1:
-		mclk_src = ref_clk.rate;
-		break;
-	case 2:
-		mclk_src = psc_mclk_in.rate;
-		break;
-	case 3:
-		mclk_src = spdif_txclk.rate;
-		break;
-	}
-
-	mclk_div = ((in_be32(&clockctl->pccr[pscnum]) >> 17) & 0x7fff) + 1;
-	clk->rate = mclk_src / mclk_div;
-}
-
-/*
- * Find all psc nodes in device tree and assign a clock
- * with name "psc%d_mclk" and dev pointing at the device
- * returned from of_find_device_by_node
- */
-static void psc_clks_init(void)
-{
-	struct device_node *np;
-	struct platform_device *ofdev;
-	u32 reg;
-	const char *psc_compat;
-
-	psc_compat = mpc512x_select_psc_compat();
-	if (!psc_compat)
-		return;
-
-	for_each_compatible_node(np, NULL, psc_compat) {
-		if (!of_property_read_u32(np, "reg", &reg)) {
-			int pscnum = (reg & 0xf00) >> 8;
-			struct clk *clk = psc_dev_clk(pscnum);
-
-			clk->flags = CLK_HAS_RATE | CLK_HAS_CTRL;
-			ofdev = of_find_device_by_node(np);
-			clk->dev = &ofdev->dev;
-			/*
-			 * AC97 is special rate clock does
-			 * not go through normal path
-			 */
-			if (of_device_is_compatible(np, "fsl,mpc5121-psc-ac97"))
-				clk->rate = ac97_clk.rate;
-			else
-				psc_calc_rate(clk, pscnum, np);
-			sprintf(clk->name, "psc%d_mclk", pscnum);
-			clk_register(clk);
-			clk_enable(clk);
-		}
-	}
-}
-
-static struct clk_interface mpc5121_clk_functions = {
-	.clk_get		= mpc5121_clk_get,
-	.clk_enable		= mpc5121_clk_enable,
-	.clk_disable		= mpc5121_clk_disable,
-	.clk_get_rate		= mpc5121_clk_get_rate,
-	.clk_put		= mpc5121_clk_put,
-	.clk_round_rate		= mpc5121_clk_round_rate,
-	.clk_set_rate		= mpc5121_clk_set_rate,
-	.clk_set_parent		= NULL,
-	.clk_get_parent		= NULL,
-};
-
-int __init mpc5121_clk_init(void)
-{
-	struct device_node *np;
-
-	np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-clock");
-	if (np) {
-		clockctl = of_iomap(np, 0);
-		of_node_put(np);
-	}
-
-	if (!clockctl) {
-		printk(KERN_ERR "Could not map clock control registers\n");
-		return 0;
-	}
-
-	rate_clks_init();
-	psc_clks_init();
-
-	/* leave clockctl mapped forever */
-	/*iounmap(clockctl); */
-	DEBUG_CLK_DUMP();
-	clocks_initialized++;
-	clk_functions = mpc5121_clk_functions;
-	return 0;
-}
diff --git a/arch/powerpc/platforms/52xx/Kconfig b/arch/powerpc/platforms/52xx/Kconfig
index 90f4496017e4..ac915bb14f3b 100644
--- a/arch/powerpc/platforms/52xx/Kconfig
+++ b/arch/powerpc/platforms/52xx/Kconfig
@@ -1,7 +1,7 @@
 config PPC_MPC52xx
 	bool "52xx-based boards"
 	depends on 6xx
-	select PPC_CLOCK
+	select COMMON_CLK
 	select PPC_PCI_CHOICE
 
 config PPC_MPC5200_SIMPLE
-- 
1.7.10.4

[PATCH v5 08/17] spi: mpc512x: adjust to OF based clock lookup

[Gerhard Sittig]

after device tree based clock lookup became available, the peripheral
driver need no longer construct clock names which include the PSC index,
remove the "psc%d_mclk" template and unconditionally use 'mclk'

acquire and release the 'ipg' clock item for register access as well

Cc: Mark Brown <broonie@kernel.org>
Cc: linux-spi@vger.kernel.org
Signed-off-by: Gerhard Sittig <gsi@denx.de>
---
 drivers/spi/spi-mpc512x-psc.c |   26 ++++++++++++++++++--------
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/drivers/spi/spi-mpc512x-psc.c b/drivers/spi/spi-mpc512x-psc.c
index 6adf4e35816d..5beb30c61a39 100644
--- a/drivers/spi/spi-mpc512x-psc.c
+++ b/drivers/spi/spi-mpc512x-psc.c
@@ -39,6 +39,7 @@ struct mpc512x_psc_spi {
 	unsigned int irq;
 	u8 bits_per_word;
 	struct clk *clk_mclk;
+	struct clk *clk_ipg;
 	u32 mclk_rate;
 
 	struct completion txisrdone;
@@ -474,8 +475,6 @@ static int mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr,
 	struct spi_master *master;
 	int ret;
 	void *tempp;
-	int psc_num;
-	char clk_name[16];
 	struct clk *clk;
 
 	master = spi_alloc_master(dev, sizeof *mps);
@@ -519,9 +518,7 @@ static int mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr,
 		goto free_master;
 	init_completion(&mps->txisrdone);
 
-	psc_num = master->bus_num;
-	snprintf(clk_name, sizeof(clk_name), "psc%d_mclk", psc_num);
-	clk = devm_clk_get(dev, clk_name);
+	clk = devm_clk_get(dev, "mclk");
 	if (IS_ERR(clk)) {
 		ret = PTR_ERR(clk);
 		goto free_irq;
@@ -532,17 +529,29 @@ static int mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr,
 	mps->clk_mclk = clk;
 	mps->mclk_rate = clk_get_rate(clk);
 
+	clk = devm_clk_get(dev, "ipg");
+	if (IS_ERR(clk)) {
+		ret = PTR_ERR(clk);
+		goto free_mclk_clock;
+	}
+	ret = clk_prepare_enable(clk);
+	if (ret)
+		goto free_mclk_clock;
+	mps->clk_ipg = clk;
+
 	ret = mpc512x_psc_spi_port_config(master, mps);
 	if (ret < 0)
-		goto free_clock;
+		goto free_ipg_clock;
 
 	ret = spi_register_master(master);
 	if (ret < 0)
-		goto free_clock;
+		goto free_ipg_clock;
 
 	return ret;
 
-free_clock:
+free_ipg_clock:
+	clk_disable_unprepare(mps->clk_ipg);
+free_mclk_clock:
 	clk_disable_unprepare(mps->clk_mclk);
 free_irq:
 	free_irq(mps->irq, mps);
@@ -561,6 +570,7 @@ static int mpc512x_psc_spi_do_remove(struct device *dev)
 
 	spi_unregister_master(master);
 	clk_disable_unprepare(mps->clk_mclk);
+	clk_disable_unprepare(mps->clk_ipg);
 	free_irq(mps->irq, mps);
 	if (mps->psc)
 		iounmap(mps->psc);
-- 
1.7.10.4

[PATCH v5 09/17] serial: mpc512x: adjust for OF based clock lookup

[Gerhard Sittig]

after device tree based clock lookup became available, the peripheral
driver need no longer construct clock names which include the PSC index,
remove the "psc%d_mclk" template and unconditionally use 'mclk'

acquire and release the "ipg" clock item for register access as well

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> # for v4
Signed-off-by: Gerhard Sittig <gsi@denx.de>
---
Greg, the difference between v4 and v5 of this patch is that v4
took the 'mclk' and 'ipg' clock items in reverse order, and thus
potentially obfuscated the adjusted name for 'mclk' -- v5 of the
patch is identical in content but cleaner diff-wise

---
 drivers/tty/serial/mpc52xx_uart.c |   40 ++++++++++++++++++++++++++++++++-----
 1 file changed, 35 insertions(+), 5 deletions(-)

diff --git a/drivers/tty/serial/mpc52xx_uart.c b/drivers/tty/serial/mpc52xx_uart.c
index 5be1df39f9f5..1d1dbe9d5af2 100644
--- a/drivers/tty/serial/mpc52xx_uart.c
+++ b/drivers/tty/serial/mpc52xx_uart.c
@@ -619,29 +619,55 @@ static irqreturn_t mpc512x_psc_handle_irq(struct uart_port *port)
 }
 
 static struct clk *psc_mclk_clk[MPC52xx_PSC_MAXNUM];
+static struct clk *psc_ipg_clk[MPC52xx_PSC_MAXNUM];
 
 /* called from within the .request_port() callback (allocation) */
 static int mpc512x_psc_alloc_clock(struct uart_port *port)
 {
 	int psc_num;
-	char clk_name[16];
 	struct clk *clk;
 	int err;
 
 	psc_num = (port->mapbase & 0xf00) >> 8;
-	snprintf(clk_name, sizeof(clk_name), "psc%d_mclk", psc_num);
-	clk = devm_clk_get(port->dev, clk_name);
+
+	clk = devm_clk_get(port->dev, "mclk");
 	if (IS_ERR(clk)) {
 		dev_err(port->dev, "Failed to get MCLK!\n");
-		return PTR_ERR(clk);
+		err = PTR_ERR(clk);
+		goto out_err;
 	}
 	err = clk_prepare_enable(clk);
 	if (err) {
 		dev_err(port->dev, "Failed to enable MCLK!\n");
-		return err;
+		goto out_err;
 	}
 	psc_mclk_clk[psc_num] = clk;
+
+	clk = devm_clk_get(port->dev, "ipg");
+	if (IS_ERR(clk)) {
+		dev_err(port->dev, "Failed to get IPG clock!\n");
+		err = PTR_ERR(clk);
+		goto out_err;
+	}
+	err = clk_prepare_enable(clk);
+	if (err) {
+		dev_err(port->dev, "Failed to enable IPG clock!\n");
+		goto out_err;
+	}
+	psc_ipg_clk[psc_num] = clk;
+
 	return 0;
+
+out_err:
+	if (psc_mclk_clk[psc_num]) {
+		clk_disable_unprepare(psc_mclk_clk[psc_num]);
+		psc_mclk_clk[psc_num] = NULL;
+	}
+	if (psc_ipg_clk[psc_num]) {
+		clk_disable_unprepare(psc_ipg_clk[psc_num]);
+		psc_ipg_clk[psc_num] = NULL;
+	}
+	return err;
 }
 
 /* called from within the .release_port() callback (release) */
@@ -656,6 +682,10 @@ static void mpc512x_psc_relse_clock(struct uart_port *port)
 		clk_disable_unprepare(clk);
 		psc_mclk_clk[psc_num] = NULL;
 	}
+	if (psc_ipg_clk[psc_num]) {
+		clk_disable_unprepare(psc_ipg_clk[psc_num]);
+		psc_ipg_clk[psc_num] = NULL;
+	}
 }
 
 /* implementation of the .clock() callback (enable/disable) */
-- 
1.7.10.4

[PATCH v5 10/17] serial: mpc512x: setup the PSC FIFO clock as well

[Gerhard Sittig]

prepare and enable the FIFO clock upon PSC FIFO initialization,
check for and propagage errors when enabling the PSC FIFO clock,
disable and unprepare the FIFO clock upon PSC FIFO uninitialization

devm_{get,put}_clk() doesn't apply here, as the SoC provides a
single FIFO component which is shared among several PSC components,
thus the FIFO isn't associated with a device (while the PSCs are)

provide a fallback clock lookup approach in case the OF based clock
lookup for the PSC FIFO fails, this allows for successful operation in
the presence of an outdated device tree which lacks clock specs

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> # for v4
Signed-off-by: Gerhard Sittig <gsi@denx.de>
---
Greg, the addition since v4 is the clk_get_sys() call for the 'ipg'
clock item (backwards compat for device trees w/o clock specs)

---
 drivers/tty/serial/mpc52xx_uart.c |   50 ++++++++++++++++++++++++++++++++-----
 1 file changed, 44 insertions(+), 6 deletions(-)

diff --git a/drivers/tty/serial/mpc52xx_uart.c b/drivers/tty/serial/mpc52xx_uart.c
index 1d1dbe9d5af2..78c8cbadc776 100644
--- a/drivers/tty/serial/mpc52xx_uart.c
+++ b/drivers/tty/serial/mpc52xx_uart.c
@@ -421,6 +421,7 @@ struct psc_fifoc {
 
 static struct psc_fifoc __iomem *psc_fifoc;
 static unsigned int psc_fifoc_irq;
+static struct clk *psc_fifoc_clk;
 
 static void mpc512x_psc_fifo_init(struct uart_port *port)
 {
@@ -568,36 +569,73 @@ static unsigned int mpc512x_psc_set_baudrate(struct uart_port *port,
 /* Init PSC FIFO Controller */
 static int __init mpc512x_psc_fifoc_init(void)
 {
+	int err;
 	struct device_node *np;
+	struct clk *clk;
+
+	/* default error code, potentially overwritten by clock calls */
+	err = -ENODEV;
 
 	np = of_find_compatible_node(NULL, NULL,
 				     "fsl,mpc5121-psc-fifo");
 	if (!np) {
 		pr_err("%s: Can't find FIFOC node\n", __func__);
-		return -ENODEV;
+		goto out_err;
+	}
+
+	clk = of_clk_get(np, 0);
+	if (IS_ERR(clk)) {
+		/* backwards compat with device trees that lack clock specs */
+		clk = clk_get_sys(np->name, "ipg");
+	}
+	if (IS_ERR(clk)) {
+		pr_err("%s: Can't lookup FIFO clock\n", __func__);
+		err = PTR_ERR(clk);
+		goto out_ofnode_put;
+	}
+	if (clk_prepare_enable(clk)) {
+		pr_err("%s: Can't enable FIFO clock\n", __func__);
+		clk_put(clk);
+		goto out_ofnode_put;
 	}
+	psc_fifoc_clk = clk;
 
 	psc_fifoc = of_iomap(np, 0);
 	if (!psc_fifoc) {
 		pr_err("%s: Can't map FIFOC\n", __func__);
-		of_node_put(np);
-		return -ENODEV;
+		goto out_clk_disable;
 	}
 
 	psc_fifoc_irq = irq_of_parse_and_map(np, 0);
-	of_node_put(np);
 	if (psc_fifoc_irq == 0) {
 		pr_err("%s: Can't get FIFOC irq\n", __func__);
-		iounmap(psc_fifoc);
-		return -ENODEV;
+		goto out_unmap;
 	}
 
+	of_node_put(np);
 	return 0;
+
+out_unmap:
+	iounmap(psc_fifoc);
+out_clk_disable:
+	clk_disable_unprepare(psc_fifoc_clk);
+	clk_put(psc_fifoc_clk);
+out_ofnode_put:
+	of_node_put(np);
+out_err:
+	return err;
 }
 
 static void __exit mpc512x_psc_fifoc_uninit(void)
 {
 	iounmap(psc_fifoc);
+
+	/* disable the clock, errors are not fatal */
+	if (psc_fifoc_clk) {
+		clk_disable_unprepare(psc_fifoc_clk);
+		clk_put(psc_fifoc_clk);
+		psc_fifoc_clk = NULL;
+	}
 }
 
 /* 512x specific interrupt handler. The caller holds the port lock */
-- 
1.7.10.4

[PATCH v5 11/17] USB: fsl-mph-dr-of: adjust for OF based clock lookup

[Gerhard Sittig]

after device tree based clock lookup became available, the peripheral
driver need no longer construct clock names which include the component
index -- remove the "usb%d_clk" template, always use "ipg" instead

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org
Signed-off-by: Gerhard Sittig <gsi@denx.de>
---
 drivers/usb/host/fsl-mph-dr-of.c |   13 +------------
 1 file changed, 1 insertion(+), 12 deletions(-)

diff --git a/drivers/usb/host/fsl-mph-dr-of.c b/drivers/usb/host/fsl-mph-dr-of.c
index abd5050a4899..9162d1b6c0a3 100644
--- a/drivers/usb/host/fsl-mph-dr-of.c
+++ b/drivers/usb/host/fsl-mph-dr-of.c
@@ -261,19 +261,8 @@ int fsl_usb2_mpc5121_init(struct platform_device *pdev)
 	struct fsl_usb2_platform_data *pdata = dev_get_platdata(&pdev->dev);
 	struct clk *clk;
 	int err;
-	char clk_name[10];
-	int base, clk_num;
-
-	base = pdev->resource->start & 0xf000;
-	if (base == 0x3000)
-		clk_num = 1;
-	else if (base == 0x4000)
-		clk_num = 2;
-	else
-		return -ENODEV;
 
-	snprintf(clk_name, sizeof(clk_name), "usb%d_clk", clk_num);
-	clk = devm_clk_get(pdev->dev.parent, clk_name);
+	clk = devm_clk_get(pdev->dev.parent, "ipg");
 	if (IS_ERR(clk)) {
 		dev_err(&pdev->dev, "failed to get clk\n");
 		return PTR_ERR(clk);
-- 
1.7.10.4

[PATCH v5 12/17] mtd: mpc5121_nfc: adjust for OF based clock lookup

[Gerhard Sittig]

after device tree based clock lookup became available, the NAND
flash driver need no longer use the previous global "nfc_clk" name,
but should use the "ipg" clock name specific to the OF node

Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: linux-mtd@lists.infradead.org
Signed-off-by: Gerhard Sittig <gsi@denx.de>
---
 drivers/mtd/nand/mpc5121_nfc.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/mpc5121_nfc.c b/drivers/mtd/nand/mpc5121_nfc.c
index 3c60a000b426..35a51a5aa537 100644
--- a/drivers/mtd/nand/mpc5121_nfc.c
+++ b/drivers/mtd/nand/mpc5121_nfc.c
@@ -729,7 +729,7 @@ static int mpc5121_nfc_probe(struct platform_device *op)
 	of_node_put(rootnode);
 
 	/* Enable NFC clock */
-	clk = devm_clk_get(dev, "nfc_clk");
+	clk = devm_clk_get(dev, "ipg");
 	if (IS_ERR(clk)) {
 		dev_err(dev, "Unable to acquire NFC clock!\n");
 		retval = PTR_ERR(clk);
-- 
1.7.10.4

[PATCH v5 13/17] [media] fsl-viu: adjust for OF based clock lookup

[Gerhard Sittig]

after device tree based clock lookup became available, the VIU driver
need no longer use the previous global "viu_clk" name, but should use
the "ipg" clock name specific to the OF node

Cc: Mauro Carvalho Chehab <m.chehab@samsung.com>
Cc: linux-media@vger.kernel.org
Signed-off-by: Gerhard Sittig <gsi@denx.de>
---
 drivers/media/platform/fsl-viu.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/platform/fsl-viu.c b/drivers/media/platform/fsl-viu.c
index fe9898ca3c84..c1e84aeb2e25 100644
--- a/drivers/media/platform/fsl-viu.c
+++ b/drivers/media/platform/fsl-viu.c
@@ -1578,7 +1578,7 @@ static int viu_of_probe(struct platform_device *op)
 	}
 
 	/* enable VIU clock */
-	clk = devm_clk_get(&op->dev, "viu_clk");
+	clk = devm_clk_get(&op->dev, "ipg");
 	if (IS_ERR(clk)) {
 		dev_err(&op->dev, "failed to lookup the clock!\n");
 		ret = PTR_ERR(clk);
-- 
1.7.10.4

[PATCH v5 14/17] net: can: mscan: adjust to common clock support for mpc512x

[Gerhard Sittig]

implement a .get_clock() callback for the MPC512x platform which uses
the common clock infrastructure (eliminating direct access to the clock
control registers from within the CAN network driver), and provide the
corresponding .put_clock() callback to release resources after use

acquire both the clock items for register access ("ipg") as well as for
wire communication ("can")

keep the previous implementation of MPC512x support in place during
migration, this results in a readable diff of the change

this change is neutral to the MPC5200 platform

Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: linux-can@vger.kernel.org
Signed-off-by: Gerhard Sittig <gsi@denx.de>
---
 drivers/net/can/mscan/mpc5xxx_can.c |  179 +++++++++++++++++++++++++++++++++++
 1 file changed, 179 insertions(+)

diff --git a/drivers/net/can/mscan/mpc5xxx_can.c b/drivers/net/can/mscan/mpc5xxx_can.c
index e59b3a392af6..f48f1297ff30 100644
--- a/drivers/net/can/mscan/mpc5xxx_can.c
+++ b/drivers/net/can/mscan/mpc5xxx_can.c
@@ -109,6 +109,177 @@ static u32 mpc52xx_can_get_clock(struct platform_device *ofdev,
 #endif /* CONFIG_PPC_MPC52xx */
 
 #ifdef CONFIG_PPC_MPC512x
+
+#if IS_ENABLED(CONFIG_COMMON_CLK)
+
+static u32 mpc512x_can_get_clock(struct platform_device *ofdev,
+				 const char *clock_source, int *mscan_clksrc)
+{
+	struct device_node *np;
+	u32 clockdiv;
+	enum {
+		CLK_FROM_AUTO,
+		CLK_FROM_IPS,
+		CLK_FROM_SYS,
+		CLK_FROM_REF,
+	} clk_from;
+	struct clk *clk_in, *clk_can;
+	unsigned long freq_calc;
+	struct mscan_priv *priv;
+	struct clk *clk_ipg;
+
+	/* the caller passed in the clock source spec that was read from
+	 * the device tree, get the optional clock divider as well
+	 */
+	np = ofdev->dev.of_node;
+	clockdiv = 1;
+	of_property_read_u32(np, "fsl,mscan-clock-divider", &clockdiv);
+	dev_dbg(&ofdev->dev, "device tree specs: clk src[%s] div[%d]\n",
+		clock_source ? clock_source : "<NULL>", clockdiv);
+
+	/* when clock-source is 'ip', the CANCTL1[CLKSRC] bit needs to
+	 * get set, and the 'ips' clock is the input to the MSCAN
+	 * component
+	 *
+	 * for clock-source values of 'ref' or 'sys' the CANCTL1[CLKSRC]
+	 * bit needs to get cleared, an optional clock-divider may have
+	 * been specified (the default value is 1), the appropriate
+	 * MSCAN related MCLK is the input to the MSCAN component
+	 *
+	 * in the absence of a clock-source spec, first an optimal clock
+	 * gets determined based on the 'sys' clock, if that fails the
+	 * 'ref' clock is used
+	 */
+	clk_from = CLK_FROM_AUTO;
+	if (clock_source) {
+		/* interpret the device tree's spec for the clock source */
+		if (!strcmp(clock_source, "ip"))
+			clk_from = CLK_FROM_IPS;
+		else if (!strcmp(clock_source, "sys"))
+			clk_from = CLK_FROM_SYS;
+		else if (!strcmp(clock_source, "ref"))
+			clk_from = CLK_FROM_REF;
+		else
+			goto err_invalid;
+		dev_dbg(&ofdev->dev, "got a clk source spec[%d]\n", clk_from);
+	}
+	if (clk_from == CLK_FROM_AUTO) {
+		/* no spec so far, try the 'sys' clock; round to the
+		 * next MHz and see if we can get a multiple of 16MHz
+		 */
+		dev_dbg(&ofdev->dev, "no clk source spec, trying SYS\n");
+		clk_in = devm_clk_get(&ofdev->dev, "sys");
+		if (IS_ERR(clk_in))
+			goto err_notavail;
+		freq_calc = clk_get_rate(clk_in);
+		freq_calc +=  499999;
+		freq_calc /= 1000000;
+		freq_calc *= 1000000;
+		if ((freq_calc % 16000000) == 0) {
+			clk_from = CLK_FROM_SYS;
+			clockdiv = freq_calc / 16000000;
+			dev_dbg(&ofdev->dev,
+				"clk fit, sys[%lu] div[%d] freq[%lu]\n",
+				freq_calc, clockdiv, freq_calc / clockdiv);
+		}
+	}
+	if (clk_from == CLK_FROM_AUTO) {
+		/* no spec so far, use the 'ref' clock */
+		dev_dbg(&ofdev->dev, "no clk source spec, trying REF\n");
+		clk_in = devm_clk_get(&ofdev->dev, "ref");
+		if (IS_ERR(clk_in))
+			goto err_notavail;
+		clk_from = CLK_FROM_REF;
+		freq_calc = clk_get_rate(clk_in);
+		dev_dbg(&ofdev->dev,
+			"clk fit, ref[%lu] (no div) freq[%lu]\n",
+			freq_calc, freq_calc);
+	}
+
+	/* select IPS or MCLK as the MSCAN input (returned to the caller),
+	 * setup the MCLK mux source and rate if applicable, apply the
+	 * optionally specified or derived above divider, and determine
+	 * the actual resulting clock rate to return to the caller
+	 */
+	switch (clk_from) {
+	case CLK_FROM_IPS:
+		clk_can = devm_clk_get(&ofdev->dev, "ips");
+		if (IS_ERR(clk_can))
+			goto err_notavail;
+		priv = netdev_priv(dev_get_drvdata(&ofdev->dev));
+		priv->clk_can = clk_can;
+		freq_calc = clk_get_rate(clk_can);
+		*mscan_clksrc = MSCAN_CLKSRC_IPS;
+		dev_dbg(&ofdev->dev, "clk from IPS, clksrc[%d] freq[%lu]\n",
+			*mscan_clksrc, freq_calc);
+		break;
+	case CLK_FROM_SYS:
+	case CLK_FROM_REF:
+		clk_can = devm_clk_get(&ofdev->dev, "mclk");
+		if (IS_ERR(clk_can))
+			goto err_notavail;
+		priv = netdev_priv(dev_get_drvdata(&ofdev->dev));
+		priv->clk_can = clk_can;
+		if (clk_from == CLK_FROM_SYS)
+			clk_in = devm_clk_get(&ofdev->dev, "sys");
+		if (clk_from == CLK_FROM_REF)
+			clk_in = devm_clk_get(&ofdev->dev, "ref");
+		if (IS_ERR(clk_in))
+			goto err_notavail;
+		clk_set_parent(clk_can, clk_in);
+		freq_calc = clk_get_rate(clk_in);
+		freq_calc /= clockdiv;
+		clk_set_rate(clk_can, freq_calc);
+		freq_calc = clk_get_rate(clk_can);
+		*mscan_clksrc = MSCAN_CLKSRC_BUS;
+		dev_dbg(&ofdev->dev, "clk from MCLK, clksrc[%d] freq[%lu]\n",
+			*mscan_clksrc, freq_calc);
+		break;
+	default:
+		goto err_invalid;
+	}
+
+	/* the above clk_can item is used for the bitrate, access to
+	 * the peripheral's register set needs the clk_ipg item
+	 */
+	clk_ipg = devm_clk_get(&ofdev->dev, "ipg");
+	if (IS_ERR(clk_ipg))
+		goto err_notavail_ipg;
+	if (clk_prepare_enable(clk_ipg))
+		goto err_notavail_ipg;
+	priv = netdev_priv(dev_get_drvdata(&ofdev->dev));
+	priv->clk_ipg = clk_ipg;
+
+	/* return the determined clock source rate */
+	return freq_calc;
+
+err_invalid:
+	dev_err(&ofdev->dev, "invalid clock source specification\n");
+	/* clock source rate could not get determined */
+	return 0;
+
+err_notavail:
+	dev_err(&ofdev->dev, "cannot acquire or setup bitrate clock source\n");
+	/* clock source rate could not get determined */
+	return 0;
+
+err_notavail_ipg:
+	dev_err(&ofdev->dev, "cannot acquire or setup register clock\n");
+	/* clock source rate could not get determined */
+	return 0;
+}
+
+static void mpc512x_can_put_clock(struct platform_device *ofdev)
+{
+	struct mscan_priv *priv;
+
+	priv = netdev_priv(dev_get_drvdata(&ofdev->dev));
+	if (priv->clk_ipg)
+		clk_disable_unprepare(priv->clk_ipg);
+}
+
+#else	/* COMMON_CLK */
+
 struct mpc512x_clockctl {
 	u32 spmr;		/* System PLL Mode Reg */
 	u32 sccr[2];		/* System Clk Ctrl Reg 1 & 2 */
@@ -239,12 +410,18 @@ exit_put:
 	of_node_put(np_clock);
 	return freq;
 }
+
+#define mpc512x_can_put_clock NULL
+
+#endif	/* COMMON_CLK */
+
 #else /* !CONFIG_PPC_MPC512x */
 static u32 mpc512x_can_get_clock(struct platform_device *ofdev,
 				 const char *clock_name, int *mscan_clksrc)
 {
 	return 0;
 }
+#define mpc512x_can_put_clock NULL
 #endif /* CONFIG_PPC_MPC512x */
 
 static const struct of_device_id mpc5xxx_can_table[];
@@ -386,11 +563,13 @@ static int mpc5xxx_can_resume(struct platform_device *ofdev)
 static const struct mpc5xxx_can_data mpc5200_can_data = {
 	.type = MSCAN_TYPE_MPC5200,
 	.get_clock = mpc52xx_can_get_clock,
+	/* .put_clock not applicable */
 };
 
 static const struct mpc5xxx_can_data mpc5121_can_data = {
 	.type = MSCAN_TYPE_MPC5121,
 	.get_clock = mpc512x_can_get_clock,
+	.put_clock = mpc512x_can_put_clock,
 };
 
 static const struct of_device_id mpc5xxx_can_table[] = {
-- 
1.7.10.4

[PATCH v5 15/17] net: can: mscan: remove non-CCF code for MPC512x

[Gerhard Sittig]

transition to the common clock framework has completed and the PPC_CLOCK
is no longer available for the MPC512x platform, remove the now obsolete
code path of the mpc5xxx mscan driver which accessed clock control module
registers directly

Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: linux-can@vger.kernel.org
Signed-off-by: Gerhard Sittig <gsi@denx.de>
---
 drivers/net/can/mscan/mpc5xxx_can.c |  141 -----------------------------------
 1 file changed, 141 deletions(-)

diff --git a/drivers/net/can/mscan/mpc5xxx_can.c b/drivers/net/can/mscan/mpc5xxx_can.c
index f48f1297ff30..6b0c9958d824 100644
--- a/drivers/net/can/mscan/mpc5xxx_can.c
+++ b/drivers/net/can/mscan/mpc5xxx_can.c
@@ -109,9 +109,6 @@ static u32 mpc52xx_can_get_clock(struct platform_device *ofdev,
 #endif /* CONFIG_PPC_MPC52xx */
 
 #ifdef CONFIG_PPC_MPC512x
-
-#if IS_ENABLED(CONFIG_COMMON_CLK)
-
 static u32 mpc512x_can_get_clock(struct platform_device *ofdev,
 				 const char *clock_source, int *mscan_clksrc)
 {
@@ -277,144 +274,6 @@ static void mpc512x_can_put_clock(struct platform_device *ofdev)
 	if (priv->clk_ipg)
 		clk_disable_unprepare(priv->clk_ipg);
 }
-
-#else	/* COMMON_CLK */
-
-struct mpc512x_clockctl {
-	u32 spmr;		/* System PLL Mode Reg */
-	u32 sccr[2];		/* System Clk Ctrl Reg 1 & 2 */
-	u32 scfr1;		/* System Clk Freq Reg 1 */
-	u32 scfr2;		/* System Clk Freq Reg 2 */
-	u32 reserved;
-	u32 bcr;		/* Bread Crumb Reg */
-	u32 pccr[12];		/* PSC Clk Ctrl Reg 0-11 */
-	u32 spccr;		/* SPDIF Clk Ctrl Reg */
-	u32 cccr;		/* CFM Clk Ctrl Reg */
-	u32 dccr;		/* DIU Clk Cnfg Reg */
-	u32 mccr[4];		/* MSCAN Clk Ctrl Reg 1-3 */
-};
-
-static struct of_device_id mpc512x_clock_ids[] = {
-	{ .compatible = "fsl,mpc5121-clock", },
-	{}
-};
-
-static u32 mpc512x_can_get_clock(struct platform_device *ofdev,
-				 const char *clock_name, int *mscan_clksrc)
-{
-	struct mpc512x_clockctl __iomem *clockctl;
-	struct device_node *np_clock;
-	struct clk *sys_clk, *ref_clk;
-	int plen, clockidx, clocksrc = -1;
-	u32 sys_freq, val, clockdiv = 1, freq = 0;
-	const u32 *pval;
-
-	np_clock = of_find_matching_node(NULL, mpc512x_clock_ids);
-	if (!np_clock) {
-		dev_err(&ofdev->dev, "couldn't find clock node\n");
-		return 0;
-	}
-	clockctl = of_iomap(np_clock, 0);
-	if (!clockctl) {
-		dev_err(&ofdev->dev, "couldn't map clock registers\n");
-		goto exit_put;
-	}
-
-	/* Determine the MSCAN device index from the peripheral's
-	 * physical address. Register address offsets against the
-	 * IMMR base are:  0x1300, 0x1380, 0x2300, 0x2380
-	 */
-	pval = of_get_property(ofdev->dev.of_node, "reg", &plen);
-	BUG_ON(!pval || plen < sizeof(*pval));
-	clockidx = (*pval & 0x80) ? 1 : 0;
-	if (*pval & 0x2000)
-		clockidx += 2;
-
-	/*
-	 * Clock source and divider selection: 3 different clock sources
-	 * can be selected: "ip", "ref" or "sys". For the latter two, a
-	 * clock divider can be defined as well. If the clock source is
-	 * not specified by the device tree, we first try to find an
-	 * optimal CAN source clock based on the system clock. If that
-	 * is not posslible, the reference clock will be used.
-	 */
-	if (clock_name && !strcmp(clock_name, "ip")) {
-		*mscan_clksrc = MSCAN_CLKSRC_IPS;
-		freq = mpc5xxx_get_bus_frequency(ofdev->dev.of_node);
-	} else {
-		*mscan_clksrc = MSCAN_CLKSRC_BUS;
-
-		pval = of_get_property(ofdev->dev.of_node,
-				       "fsl,mscan-clock-divider", &plen);
-		if (pval && plen == sizeof(*pval))
-			clockdiv = *pval;
-		if (!clockdiv)
-			clockdiv = 1;
-
-		if (!clock_name || !strcmp(clock_name, "sys")) {
-			sys_clk = devm_clk_get(&ofdev->dev, "sys_clk");
-			if (IS_ERR(sys_clk)) {
-				dev_err(&ofdev->dev, "couldn't get sys_clk\n");
-				goto exit_unmap;
-			}
-			/* Get and round up/down sys clock rate */
-			sys_freq = 1000000 *
-				((clk_get_rate(sys_clk) + 499999) / 1000000);
-
-			if (!clock_name) {
-				/* A multiple of 16 MHz would be optimal */
-				if ((sys_freq % 16000000) == 0) {
-					clocksrc = 0;
-					clockdiv = sys_freq / 16000000;
-					freq = sys_freq / clockdiv;
-				}
-			} else {
-				clocksrc = 0;
-				freq = sys_freq / clockdiv;
-			}
-		}
-
-		if (clocksrc < 0) {
-			ref_clk = devm_clk_get(&ofdev->dev, "ref_clk");
-			if (IS_ERR(ref_clk)) {
-				dev_err(&ofdev->dev, "couldn't get ref_clk\n");
-				goto exit_unmap;
-			}
-			clocksrc = 1;
-			freq = clk_get_rate(ref_clk) / clockdiv;
-		}
-	}
-
-	/* Disable clock */
-	out_be32(&clockctl->mccr[clockidx], 0x0);
-	if (clocksrc >= 0) {
-		/* Set source and divider */
-		val = (clocksrc << 14) | ((clockdiv - 1) << 17);
-		out_be32(&clockctl->mccr[clockidx], val);
-		/* Enable clock */
-		out_be32(&clockctl->mccr[clockidx], val | 0x10000);
-	}
-
-	/* Enable MSCAN clock domain */
-	val = in_be32(&clockctl->sccr[1]);
-	if (!(val & (1 << 25)))
-		out_be32(&clockctl->sccr[1], val | (1 << 25));
-
-	dev_dbg(&ofdev->dev, "using '%s' with frequency divider %d\n",
-		*mscan_clksrc == MSCAN_CLKSRC_IPS ? "ips_clk" :
-		clocksrc == 1 ? "ref_clk" : "sys_clk", clockdiv);
-
-exit_unmap:
-	iounmap(clockctl);
-exit_put:
-	of_node_put(np_clock);
-	return freq;
-}
-
-#define mpc512x_can_put_clock NULL
-
-#endif	/* COMMON_CLK */
-
 #else /* !CONFIG_PPC_MPC512x */
 static u32 mpc512x_can_get_clock(struct platform_device *ofdev,
 				 const char *clock_name, int *mscan_clksrc)
-- 
1.7.10.4

[PATCH v5 16/17] powerpc/mpc512x: improve DIU related clock setup

[Gerhard Sittig]

adapt the DIU clock initialization to the COMMON_CLK approach:
device tree based clock lookup, prepare and unprepare for clocks,
work with frequencies not dividers, call the appropriate clk_*()
routines and don't access CCM registers

the "best clock" determination now completely relies on the
platform's clock driver to pick a frequency close to what the
caller requests, and merely checks whether the desired frequency
was met (fits the tolerance of the monitor)

this approach shall succeed upon first try in the usual case,
will test a few less desirable yet acceptable frequencies in
edge cases, and will fallback to "best effort" if none of the
previously tried frequencies pass the test

provide a fallback clock lookup approach in case the OF based clock
lookup for the DIU fails, this allows for successful operation in
the presence of an outdated device tree which lacks clock specs

Cc: Anatolij Gustschin <agust@denx.de>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Gerhard Sittig <gsi@denx.de>
---
 arch/powerpc/platforms/512x/mpc512x_shared.c |  169 ++++++++++++++------------
 1 file changed, 92 insertions(+), 77 deletions(-)

diff --git a/arch/powerpc/platforms/512x/mpc512x_shared.c b/arch/powerpc/platforms/512x/mpc512x_shared.c
index a82a41b4fd91..d8f172b710a8 100644
--- a/arch/powerpc/platforms/512x/mpc512x_shared.c
+++ b/arch/powerpc/platforms/512x/mpc512x_shared.c
@@ -12,6 +12,7 @@
  * (at your option) any later version.
  */
 
+#include <linux/clk.h>
 #include <linux/kernel.h>
 #include <linux/io.h>
 #include <linux/irq.h>
@@ -70,98 +71,112 @@ struct fsl_diu_shared_fb {
 	bool		in_use;
 };
 
-#define DIU_DIV_MASK	0x000000ff
+/* receives a pixel clock spec in pico seconds, adjusts the DIU clock rate */
 void mpc512x_set_pixel_clock(unsigned int pixclock)
 {
-	unsigned long bestval, bestfreq, speed, busfreq;
-	unsigned long minpixclock, maxpixclock, pixval;
-	struct mpc512x_ccm __iomem *ccm;
 	struct device_node *np;
-	u32 temp;
-	long err;
-	int i;
+	struct clk *clk_diu;
+	unsigned long epsilon, minpixclock, maxpixclock;
+	unsigned long offset, want, got, delta;
 
-	np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-clock");
+	/* lookup and enable the DIU clock */
+	np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-diu");
 	if (!np) {
-		pr_err("Can't find clock control module.\n");
+		pr_err("Could not find DIU device tree node.\n");
 		return;
 	}
-
-	ccm = of_iomap(np, 0);
+	clk_diu = of_clk_get(np, 0);
+	if (IS_ERR(clk_diu)) {
+		/* backwards compat with device trees that lack clock specs */
+		clk_diu = clk_get_sys(np->name, "ipg");
+	}
 	of_node_put(np);
-	if (!ccm) {
-		pr_err("Can't map clock control module reg.\n");
+	if (IS_ERR(clk_diu)) {
+		pr_err("Could not lookup DIU clock.\n");
 		return;
 	}
-
-	np = of_find_node_by_type(NULL, "cpu");
-	if (np) {
-		const unsigned int *prop =
-			of_get_property(np, "bus-frequency", NULL);
-
-		of_node_put(np);
-		if (prop) {
-			busfreq = *prop;
-		} else {
-			pr_err("Can't get bus-frequency property\n");
-			return;
-		}
-	} else {
-		pr_err("Can't find 'cpu' node.\n");
+	if (clk_prepare_enable(clk_diu)) {
+		pr_err("Could not enable DIU clock.\n");
 		return;
 	}
 
-	/* Pixel Clock configuration */
-	pr_debug("DIU: Bus Frequency = %lu\n", busfreq);
-	speed = busfreq * 4; /* DIU_DIV ratio is 4 * CSB_CLK / DIU_CLK */
-
-	/* Calculate the pixel clock with the smallest error */
-	/* calculate the following in steps to avoid overflow */
-	pr_debug("DIU pixclock in ps - %d\n", pixclock);
-	temp = (1000000000 / pixclock) * 1000;
-	pixclock = temp;
-	pr_debug("DIU pixclock freq - %u\n", pixclock);
-
-	temp = temp / 20; /* pixclock * 0.05 */
-	pr_debug("deviation = %d\n", temp);
-	minpixclock = pixclock - temp;
-	maxpixclock = pixclock + temp;
-	pr_debug("DIU minpixclock - %lu\n", minpixclock);
-	pr_debug("DIU maxpixclock - %lu\n", maxpixclock);
-	pixval = speed/pixclock;
-	pr_debug("DIU pixval = %lu\n", pixval);
-
-	err = LONG_MAX;
-	bestval = pixval;
-	pr_debug("DIU bestval = %lu\n", bestval);
-
-	bestfreq = 0;
-	for (i = -1; i <= 1; i++) {
-		temp = speed / (pixval+i);
-		pr_debug("DIU test pixval i=%d, pixval=%lu, temp freq. = %u\n",
-			i, pixval, temp);
-		if ((temp < minpixclock) || (temp > maxpixclock))
-			pr_debug("DIU exceeds monitor range (%lu to %lu)\n",
-				minpixclock, maxpixclock);
-		else if (abs(temp - pixclock) < err) {
-			pr_debug("Entered the else if block %d\n", i);
-			err = abs(temp - pixclock);
-			bestval = pixval + i;
-			bestfreq = temp;
-		}
+	/*
+	 * convert the picoseconds spec into the desired clock rate,
+	 * determine the acceptable clock range for the monitor (+/- 5%),
+	 * do the calculation in steps to avoid integer overflow
+	 */
+	pr_debug("DIU pixclock in ps - %u\n", pixclock);
+	pixclock = (1000000000 / pixclock) * 1000;
+	pr_debug("DIU pixclock freq  - %u\n", pixclock);
+	epsilon = pixclock / 20; /* pixclock * 0.05 */
+	pr_debug("DIU deviation      - %lu\n", epsilon);
+	minpixclock = pixclock - epsilon;
+	maxpixclock = pixclock + epsilon;
+	pr_debug("DIU minpixclock    - %lu\n", minpixclock);
+	pr_debug("DIU maxpixclock    - %lu\n", maxpixclock);
+
+	/*
+	 * check whether the DIU supports the desired pixel clock
+	 *
+	 * - simply request the desired clock and see what the
+	 *   platform's clock driver will make of it, assuming that it
+	 *   will setup the best approximation of the requested value
+	 * - try other candidate frequencies in the order of decreasing
+	 *   preference (i.e. with increasing distance from the desired
+	 *   pixel clock, and checking the lower frequency before the
+	 *   higher frequency to not overload the hardware) until the
+	 *   first match is found -- any potential subsequent match
+	 *   would only be as good as the former match or typically
+	 *   would be less preferrable
+	 *
+	 * the offset increment of pixelclock divided by 64 is an
+	 * arbitrary choice -- it's simple to calculate, in the typical
+	 * case we expect the first check to succeed already, in the
+	 * worst case seven frequencies get tested (the exact center and
+	 * three more values each to the left and to the right) before
+	 * the 5% tolerance window is exceeded, resulting in fast enough
+	 * execution yet high enough probability of finding a suitable
+	 * value, while the error rate will be in the order of single
+	 * percents
+	 */
+	for (offset = 0; offset <= epsilon; offset += pixclock / 64) {
+		want = pixclock - offset;
+		pr_debug("DIU checking clock - %lu\n", want);
+		clk_set_rate(clk_diu, want);
+		got = clk_get_rate(clk_diu);
+		delta = abs(pixclock - got);
+		if (delta < epsilon)
+			break;
+		if (!offset)
+			continue;
+		want = pixclock + offset;
+		pr_debug("DIU checking clock - %lu\n", want);
+		clk_set_rate(clk_diu, want);
+		got = clk_get_rate(clk_diu);
+		delta = abs(pixclock - got);
+		if (delta < epsilon)
+			break;
 	}
+	if (offset <= epsilon) {
+		pr_debug("DIU clock accepted - %lu\n", want);
+		pr_debug("DIU pixclock want %u, got %lu, delta %lu, eps %lu\n",
+			 pixclock, got, delta, epsilon);
+		return;
+	}
+	pr_warn("DIU pixclock auto search unsuccessful\n");
 
-	pr_debug("DIU chose = %lx\n", bestval);
-	pr_debug("DIU error = %ld\n NomPixClk ", err);
-	pr_debug("DIU: Best Freq = %lx\n", bestfreq);
-	/* Modify DIU_DIV in CCM SCFR1 */
-	temp = in_be32(&ccm->scfr1);
-	pr_debug("DIU: Current value of SCFR1: 0x%08x\n", temp);
-	temp &= ~DIU_DIV_MASK;
-	temp |= (bestval & DIU_DIV_MASK);
-	out_be32(&ccm->scfr1, temp);
-	pr_debug("DIU: Modified value of SCFR1: 0x%08x\n", temp);
-	iounmap(ccm);
+	/*
+	 * what is the most appropriate action to take when the search
+	 * for an available pixel clock which is acceptable to the
+	 * monitor has failed?  disable the DIU (clock) or just provide
+	 * a "best effort"?  we go with the latter
+	 */
+	pr_warn("DIU pixclock best effort fallback (backend's choice)\n");
+	clk_set_rate(clk_diu, pixclock);
+	got = clk_get_rate(clk_diu);
+	delta = abs(pixclock - got);
+	pr_debug("DIU pixclock want %u, got %lu, delta %lu, eps %lu\n",
+		 pixclock, got, delta, epsilon);
 }
 
 enum fsl_diu_monitor_port
-- 
1.7.10.4

[PATCH v5 17/17] clk: mpc512x: remove migration support workarounds

[Gerhard Sittig]

this change removes workarounds which have become obsolete after
migration to common clock support has completed
- remove clkdev registration calls (compatibility clock item aliases)
  after all peripheral drivers were adjusted for device tree based
  clock lookup
- remove pre-enable workarounds after all peripheral drivers were
  adjusted to acquire their respective clock items

workarounds for these clock items get removed:  FEC (ethernet), I2C,
PSC (UART, SPI), PSC FIFO, USB, NFC (NAND flash), VIU (video capture),
BDLC (CAN), CAN MCLK, DIU (video output)

these clkdev registered names won't be provided any longer by the
MPC512x platform's clock driver:  "psc%d_mclk", "mscan%d_mclk",
"usb%d_clk", "nfc_clk", "viu_clk", "sys_clk", "ref_clk"

the pre-enable workaround for PCI remains, but depends on the presence
of PCI related device tree nodes (disables the PCI clock in the absence
of PCI nodes, keeps the PCI clock enabled in the presence of nodes) --
moving clock acquisition into the peripheral driver isn't possible for
PCI because its initialization takes place before the platform clock
driver gets initialized, thus the clock provider isn't available then

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>
---
 arch/powerpc/platforms/512x/clock-commonclk.c |   50 ++++++++-----------------
 1 file changed, 16 insertions(+), 34 deletions(-)

diff --git a/arch/powerpc/platforms/512x/clock-commonclk.c b/arch/powerpc/platforms/512x/clock-commonclk.c
index c1faf3a9ea1f..b1fbdcbc68b7 100644
--- a/arch/powerpc/platforms/512x/clock-commonclk.c
+++ b/arch/powerpc/platforms/512x/clock-commonclk.c
@@ -695,46 +695,28 @@ static void mpc5121_clk_register_of_provider(struct device_node *np)
  */
 static void mpc5121_clk_provide_migration_support(void)
 {
-	int idx;
-	char name[32];
-
-	/*
-	 * provide "pre-CCF" alias clock names for peripheral drivers
-	 * which have not yet been adjusted to do OF based clock lookups
-	 */
-	clk_register_clkdev(clks[MPC512x_CLK_REF], "ref_clk", NULL);
-	clk_register_clkdev(clks[MPC512x_CLK_SYS], "sys_clk", NULL);
-	clk_register_clkdev(clks[MPC512x_CLK_VIU], "viu_clk", NULL);
-	clk_register_clkdev(clks[MPC512x_CLK_NFC], "nfc_clk", NULL);
-	clk_register_clkdev(clks[MPC512x_CLK_USB1], "usb1_clk", NULL);
-	clk_register_clkdev(clks[MPC512x_CLK_USB2], "usb2_clk", NULL);
-	for (idx = 0; idx < NR_PSCS; idx++) {
-		snprintf(name, sizeof(name), "psc%d_mclk", idx);
-		clk_register_clkdev(clks[MPC512x_CLK_PSC0_MCLK + idx],
-				    name, NULL);
-	}
-	for (idx = 0; idx < NR_MSCANS; idx++) {
-		snprintf(name, sizeof(name), "mscan%d_mclk", idx);
-		clk_register_clkdev(clks[MPC512x_CLK_MSCAN0_MCLK + idx],
-				    name, NULL);
-	}
-	clk_register_clkdev(clks[MPC512x_CLK_SPDIF_MCLK], "spdif_mclk", NULL);
 
 	/*
 	 * pre-enable those clock items which are not yet appropriately
 	 * acquired by their peripheral driver
+	 *
+	 * the PCI clock cannot get acquired by its peripheral driver,
+	 * because for this platform the driver won't probe(), instead
+	 * initialization is done from within the .setup_arch() routine
+	 * at a point in time where the clock provider has not been
+	 * setup yet and thus isn't available yet
+	 *
+	 * so we "pre-enable" the clock here, to not have the clock
+	 * subsystem automatically disable this item in a late init call
+	 *
+	 * this PCI clock pre-enable workaround only applies when there
+	 * are device tree nodes for PCI and thus the peripheral driver
+	 * has attached to bridges, otherwise the PCI clock remains
+	 * unused and so it gets disabled
 	 */
-	clk_prepare_enable(clks[MPC512x_CLK_PSC_FIFO]);
 	clk_prepare_enable(clks[MPC512x_CLK_PSC3_MCLK]);/* serial console */
-	clk_prepare_enable(clks[MPC512x_CLK_FEC]);	/* network, NFS */
-	clk_prepare_enable(clks[MPC512x_CLK_DIU]);	/* display */
-	clk_prepare_enable(clks[MPC512x_CLK_I2C]);	/* I2C */
-	for (idx = 0; idx < NR_PSCS; idx++)		/* PSC ipg */
-		clk_prepare_enable(clks[MPC512x_CLK_PSC0 + idx]);
-	clk_prepare_enable(clks[MPC512x_CLK_BDLC]);	/* MSCAN ipg */
-	for (idx = 0; idx < NR_MSCANS; idx++)		/* MSCAN mclk */
-		clk_prepare_enable(clks[MPC512x_CLK_MSCAN0_MCLK + idx]);
-	clk_prepare_enable(clks[MPC512x_CLK_PCI]);	/* PCI */
+	if (of_find_compatible_node(NULL, "pci", "fsl,mpc5121-pci"))
+		clk_prepare_enable(clks[MPC512x_CLK_PCI]);
 }
 
 /*
-- 
1.7.10.4

Re: [PATCH v5 01/17] powerpc/fsl-pci: improve clock API use

[Scott Wood]

On Mon, 2013-11-18 at 00:06 +0100, Gerhard Sittig wrote:
> make the Freescale PCI driver get, prepare and enable the PCI clock
> during probe(); the clock gets put upon device shutdown by the devm
> approach
> 
> clock lookup is non-fatal as not all platforms may provide clock specs
> in their device tree or implement a device tree based clock provider,
> but failure to enable clocks after successful lookup is fatal
> 
> the driver appears to not have a remove() routine, so no reference to
> the clock is kept during use, and the clock isn't released (the devm
> approach will put the clock, but it won't get disabled or unprepared)
> 
> the 85xx/86xx platforms go through the probe() routine, where clock
> lookup occurs and the clock gets acquired if one was specified; the
> 512x/83xx platforms don't pass through probe() but instead directly call
> the add_bridge() routine at a point in time where the clock provider has
> not been setup yet even if the platform implements one -- add comments
> to the code paths as a reminder for the potential need of a workaround
> in the platform's clock driver, and to keep awareness if code should get
> re-arranged or moved
> 
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Kumar Gala <galak@kernel.crashing.org>
> Cc: linuxppc-dev@lists.ozlabs.org
> Signed-off-by: Gerhard Sittig <gsi@denx.de>
> ---
>  arch/powerpc/sysdev/fsl_pci.c |   52 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 52 insertions(+)

Please coordinate this change with Minghuan Lian's patchset (posted Oct
23) to move the bulk of this driver outside of arch/powerpc.


> diff --git a/arch/powerpc/sysdev/fsl_pci.c b/arch/powerpc/sysdev/fsl_pci.c
> index ccfb50ddfe38..efa0916f61b6 100644
> --- a/arch/powerpc/sysdev/fsl_pci.c
> +++ b/arch/powerpc/sysdev/fsl_pci.c
> @@ -17,6 +17,8 @@
>   * Free Software Foundation;  either version 2 of the  License, or (at your
>   * option) any later version.
>   */
> +
> +#include <linux/clk.h>
>  #include <linux/kernel.h>
>  #include <linux/pci.h>
>  #include <linux/delay.h>
> @@ -755,6 +757,32 @@ int __init mpc83xx_add_bridge(struct device_node *dev)
>  	const int *bus_range;
>  	int primary;
>  
> +	/*
> +	 * 85xx/86xx platforms take the path through the probe() routine
> +	 * as one would expect, PCI related clocks get acquired there if
> +	 * specified
> +	 *
> +	 * 83xx/512x _don't_ pass through probe(), this add_bridge()
> +	 * routine instead is called from within .setup_arch() at a
> +	 * point in time where clock providers haven't been setup yet;
> +	 * so clocks cannot get acquired here -- lookup would always
> +	 * fail even on those platforms which implement the provider
> +	 *
> +	 * there is no counterpart for add_bridge() just like there is
> +	 * no remove() counterpart for probe(), so in either case the
> +	 * PCI related clock won't get released, and all of the
> +	 * 512x/83xx/85xx/86xx platforms behave in identical ways

How is it identical if 85xx/86xx will acquire a clock in probe(), but
83xx/512x can't acquire it in add_bridge()?

Could you explain the relevance of releasing clocks here?

> +	 *
> +	 * this comment is here to "keep the balance" against the
> +	 * probe() routine, and as a reminder to acquire clocks if the
> +	 * add_bridge() call should move to some later point in time
> +	 *
> +	 * until then clock providers are expected to work around the
> +	 * peripheral driver's not acquiring the PCI clock on those
> +	 * platforms where clock providers exist, while nothing needs to
> +	 * be done for those platforms without a clock provider
> +	 */

What would be involved in moving 83xx/512x to use .probe() as well?

>  	is_mpc83xx_pci = 1;
>  
>  	if (!of_device_is_available(dev)) {
> @@ -1086,9 +1114,33 @@ void fsl_pci_assign_primary(void)
>  
>  static int fsl_pci_probe(struct platform_device *pdev)
>  {
> +	struct clk *clk;
>  	int ret;
>  	struct device_node *node;
>  
> +	/*
> +	 * clock lookup is non-fatal since the driver is shared among
> +	 * platforms and not all of them provide clocks specs in their
> +	 * device tree, but failure to enable a specified clock is
> +	 * considered fatal
> +	 *
> +	 * note that only the 85xx and 86xx platforms pass through this
> +	 * probe() routine, while 83xx and 512x directly invoke the
> +	 * mpc83xx_add_bridge() routine from within .setup_arch() code
> +	 */
> +	clk = devm_clk_get(&pdev->dev, "ipg");
> +	if (!IS_ERR(clk)) {
> +		ret = clk_prepare_enable(clk);
> +		if (ret) {
> +			dev_err(&pdev->dev, "Could not enable PCI clock\n");
> +			return ret;
> +		}
> +		/*
> +		 * TODO where to store the 'clk' reference?  there appears
> +		 * to be no remove() routine which undoes what probe() does
> +		 */
> +	}

There is a .remove(); this driver just doesn't support it.

As for where to store things, you could turn private_data into a struct
rather than a direct iomem pointer.  Or just replace the comment with a
non-TODO statement that says we'll never release the clock because the
PCI controller driver is non-removable.

-Scott

Re: [PATCH v5 01/17] powerpc/fsl-pci: improve clock API use

[Gerhard Sittig]

[ summary:  the PCI driver change of mine looks innocent yet
  raises questions (not for the current situation, but in the
  face of potential future changes); these concerns were not
  introduced by me but were "inherited" from the former
  implementation, as I understand it

  let's drop my patch now, have the Layerscape series show up,
  and add proper clock handling to the PCI peripheral driver
  later, while in the meantime either nothing needs to be done
  (83xx, 85xx, 86xx) or workarounds do their job (512x)

  should 8xxx platforms want to introduce CCF support, they can
  and may apply the same workaround as 512x ]

On Tue, Nov 19, 2013 at 16:41 -0600, Scott Wood wrote:
> 
> On Mon, 2013-11-18 at 00:06 +0100, Gerhard Sittig wrote:
> > make the Freescale PCI driver get, prepare and enable the PCI clock
> > during probe(); the clock gets put upon device shutdown by the devm
> > approach
> > 
> > clock lookup is non-fatal as not all platforms may provide clock specs
> > in their device tree or implement a device tree based clock provider,
> > but failure to enable clocks after successful lookup is fatal
> > 
> > the driver appears to not have a remove() routine, so no reference to
> > the clock is kept during use, and the clock isn't released (the devm
> > approach will put the clock, but it won't get disabled or unprepared)
> > 
> > the 85xx/86xx platforms go through the probe() routine, where clock
> > lookup occurs and the clock gets acquired if one was specified; the
> > 512x/83xx platforms don't pass through probe() but instead directly call
> > the add_bridge() routine at a point in time where the clock provider has
> > not been setup yet even if the platform implements one -- add comments
> > to the code paths as a reminder for the potential need of a workaround
> > in the platform's clock driver, and to keep awareness if code should get
> > re-arranged or moved
> > 
> > Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> > Cc: Paul Mackerras <paulus@samba.org>
> > Cc: Kumar Gala <galak@kernel.crashing.org>
> > Cc: linuxppc-dev@lists.ozlabs.org
> > Signed-off-by: Gerhard Sittig <gsi@denx.de>
> > ---
> >  arch/powerpc/sysdev/fsl_pci.c |   52 +++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 52 insertions(+)
> 
> Please coordinate this change with Minghuan Lian's patchset (posted Oct
> 23) to move the bulk of this driver outside of arch/powerpc.

Ah, you Cc'ed him, good.  I spotted an earlier RFC submission,
but somehow missed more recent updates.  With the move of the
fsl_pci driver into pcie my comments partially turn into lies as
the driver will grow .remove() support.

What's necessary upon remove is along the lines of b3bfce2b "i2c:
mpc: cleanup clock API use" or 2771399a "fs_enet: cleanup clock
API use" (when clocks were not acquired at all) or something like
180890c7 "mtd: mpc5121_nfc: cleanup clock API use" or 7282bdb2
"USB: fsl-mph-dr-of: cleanup clock API use" (when clocks were
acquired but not fully prepared).  With the introduction of
remove support this is just about keeping a reference to the
acquired clock to disable and unprepare it, putting the clock is
done by the devm mechanism.

For the time being I'd suggest to skip this PCI driver clock API
use cleanup patch of mine if the Layerscape PCI patch is more
probable to make it into mainline, and I shall re-submit after
the Layerscape patch was applied.

If my patch is taken before the Layerscape change, then the
latter would have to "postprocess" and update mine.  Which would
be straight forward but might be out of the scope of a "move
code" commit.

I'm fine with either approach, dropping my PCI patch now, or
applying it and adding PCI clock release to .remove within the
Layerscape series.


> > diff --git a/arch/powerpc/sysdev/fsl_pci.c b/arch/powerpc/sysdev/fsl_pci.c
> > index ccfb50ddfe38..efa0916f61b6 100644
> > --- a/arch/powerpc/sysdev/fsl_pci.c
> > +++ b/arch/powerpc/sysdev/fsl_pci.c
> > @@ -17,6 +17,8 @@
> >   * Free Software Foundation;  either version 2 of the  License, or (at your
> >   * option) any later version.
> >   */
> > +
> > +#include <linux/clk.h>
> >  #include <linux/kernel.h>
> >  #include <linux/pci.h>
> >  #include <linux/delay.h>
> > @@ -755,6 +757,32 @@ int __init mpc83xx_add_bridge(struct device_node *dev)
> >  	const int *bus_range;
> >  	int primary;
> >  
> > +	/*
> > +	 * 85xx/86xx platforms take the path through the probe() routine
> > +	 * as one would expect, PCI related clocks get acquired there if
> > +	 * specified
> > +	 *
> > +	 * 83xx/512x _don't_ pass through probe(), this add_bridge()
> > +	 * routine instead is called from within .setup_arch() at a
> > +	 * point in time where clock providers haven't been setup yet;
> > +	 * so clocks cannot get acquired here -- lookup would always
> > +	 * fail even on those platforms which implement the provider
> > +	 *
> > +	 * there is no counterpart for add_bridge() just like there is
> > +	 * no remove() counterpart for probe(), so in either case the
> > +	 * PCI related clock won't get released, and all of the
> > +	 * 512x/83xx/85xx/86xx platforms behave in identical ways
> 
> How is it identical if 85xx/86xx will acquire a clock in probe(), but
> 83xx/512x can't acquire it in add_bridge()?
> 
> Could you explain the relevance of releasing clocks here?

The situation I found was that none of the platforms which use
this fsl_pci driver did acquire any PCI related clock, all of
them "just used the hardware" and assumed that "someone" will
have setup and enabled the clock (some boot loader maybe).

The structure of the fsl_pci driver with its attaching but not
detaching from the hardware made things easy.  I assumed that
this is because there may be boot media or mass storage connected
to PCI which you don't want to lose and which you don't want to
disconnect from upon shutdown.

So the previous situation for all platforms is
- 512x, 83xx, 85xx, 86xx:  don't setup the clock, just use the
  hardware, just works


What my PCI driver clock API use cleanup patch does is to add a
clock lookup to the .probe() routine, fail silently if there is
no clock spec or no clock provider, do setup the clock when a
spec was found.

So the intermediate situation for all platforms is
- 512x, 83xx:  initialization in .setup_arch(), call to
  add_bridge(), don't setup the clock, just use the hardware,
  still works
- 85xx, 86xx:  initialization in .probe(), clock lookup, silent
  failure, don't setup the clock, just use the hardware, still
  works


Then CCF support gets added to 512x, including migration support.
The situation then is
- 512x:  .setup_arch calls add_bridge, nothing is done to the
  clock; CCF provider registers the PCI clock item, pre-enables
  the clock item;  late init finds the PCI clock "in use"
  (pre-enabled) and leaves it enabled; things keep working
- 83xx:  .setup_arch and add_bridge, no clock handling, no CCF
  provider either, so no "disable unused" step, all the same
- 85xx, 86xx:  .probe, no clock handling, no CCF "disable
  unused", all the same

Then peripheral drivers get adjusted after CCF has become
available, nothing changes for PCI here.

Then CCF migration support gets removed for 512x.  The situation
is then:
- 512x:  .setup_arch and add_bridge, no clock related setup; CCF
  provider registers PCI clock item, leaves it alone in the
  absence of PCI related OF nodes, pre-enables it in the presence
  of PCI related OF nodes; CCF "disable unuses" leaves PCI clock
  active, PCI still operational
- 83xx, 85xx, 86xx: no change


So before my series, "someone" (a bootloader) sets up the PCI
clock, the driver does nothing with it.

With my series, the CCF provider introduces a PCI clock item, it
gets enabled and remains active, the driver still does nothing to
the clock item.  Those platforms without a CCF provider won't
disable the clock item.

Other series may introduce CCF providers for 83xx/85xx/86xx,
these might apply the same workarounds for migration as the 512x
code does.

Yes, I am aware of CCF code for "corenet".  But my understanding
is that this only manages a few PLLs and only applies to CPU
cores, not to peripherals and the complete clock tree.


> > +	 *
> > +	 * this comment is here to "keep the balance" against the
> > +	 * probe() routine, and as a reminder to acquire clocks if the
> > +	 * add_bridge() call should move to some later point in time
> > +	 *
> > +	 * until then clock providers are expected to work around the
> > +	 * peripheral driver's not acquiring the PCI clock on those
> > +	 * platforms where clock providers exist, while nothing needs to
> > +	 * be done for those platforms without a clock provider
> > +	 */
> 
> What would be involved in moving 83xx/512x to use .probe() as well?

Oh, that's a completely different can of worms.  I dare to judge
what my approach does, as it is minimal and keeps the order of
steps in place.

Rearranging the PCI initialization order is way beyond my
capabilities (both in coding as well as testing).  Considering
that I only noticed rather late that 512x won't pass through
probe() and that I might even have broken compilation with an
early submission, I'd rather not start fiddling with this stuff.
My contribution would just not be helpful.


> >  	is_mpc83xx_pci = 1;
> >  
> >  	if (!of_device_is_available(dev)) {
> > @@ -1086,9 +1114,33 @@ void fsl_pci_assign_primary(void)
> >  
> >  static int fsl_pci_probe(struct platform_device *pdev)
> >  {
> > +	struct clk *clk;
> >  	int ret;
> >  	struct device_node *node;
> >  
> > +	/*
> > +	 * clock lookup is non-fatal since the driver is shared among
> > +	 * platforms and not all of them provide clocks specs in their
> > +	 * device tree, but failure to enable a specified clock is
> > +	 * considered fatal
> > +	 *
> > +	 * note that only the 85xx and 86xx platforms pass through this
> > +	 * probe() routine, while 83xx and 512x directly invoke the
> > +	 * mpc83xx_add_bridge() routine from within .setup_arch() code
> > +	 */
> > +	clk = devm_clk_get(&pdev->dev, "ipg");
> > +	if (!IS_ERR(clk)) {
> > +		ret = clk_prepare_enable(clk);
> > +		if (ret) {
> > +			dev_err(&pdev->dev, "Could not enable PCI clock\n");
> > +			return ret;
> > +		}
> > +		/*
> > +		 * TODO where to store the 'clk' reference?  there appears
> > +		 * to be no remove() routine which undoes what probe() does
> > +		 */
> > +	}
> 
> There is a .remove(); this driver just doesn't support it.
> 
> As for where to store things, you could turn private_data into a struct
> rather than a direct iomem pointer.  Or just replace the comment with a
> non-TODO statement that says we'll never release the clock because the
> PCI controller driver is non-removable.

Re-considering the above, the most appropriate thing to do may be
to drop my patch now, and see how the Layerscape series evolves.

Once there is a PCI driver which works on all the platforms and
has the probe and remove counterparts, adding proper clock
handling to the peripheral driver is straight forward (along the
lines of the above mentioned i2c and fs_enet changes).


virtually yours
Gerhard Sittig
-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr. 5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-0 Fax: +49-8142-66989-80  Email: office@denx.de

Re: [PATCH v5 00/17] add COMMON_CLK support for PowerPC MPC512x

[Gerhard Sittig]

On Mon, Nov 18, 2013 at 00:06 +0100, Gerhard Sittig wrote:
> 
> the series is based on v3.12, but I'll rebase against v3.13-rc1
> (when available) or any other subtree upon request

Now that v3.13-rc1 is out, I noticed that the series no longer
applies cleanly (minor context changes and conflicts) and needs
minor adjustment.

Compilation of 4/17 requires <linux/of_address.h> which no longer
is included implicitly.

PPC_CLOCK removal in 7/17 should remove <asm/clk_interface.h> as
well after all references to this header file have gone.  (And
the context of the patch has changed.)

The context of 16/17 for DIU initialization has changed.

I'll wait for a few more days whether there is more feedback for
v5 (especially on the device tree backwards compat approach),
then will rebase and send out v6 of the series.


virtually yours
Gerhard Sittig
-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr. 5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-0 Fax: +49-8142-66989-80  Email: office@denx.de

Re: [PATCH v5 08/17] spi: mpc512x: adjust to OF based clock lookup

[Mark Brown]

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On Mon, Nov 18, 2013 at 12:06:08AM +0100, Gerhard Sittig wrote:
> after device tree based clock lookup became available, the peripheral
> driver need no longer construct clock names which include the PSC index,
> remove the "psc%d_mclk" template and unconditionally use 'mclk'

Have there been other changes which make this happen?

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Re: [PATCH v5 08/17] spi: mpc512x: adjust to OF based clock lookup

[Gerhard Sittig]

On Mon, Nov 25, 2013 at 17:30 +0000, Mark Brown wrote:
> 
> On Mon, Nov 18, 2013 at 12:06:08AM +0100, Gerhard Sittig wrote:
> > after device tree based clock lookup became available, the peripheral
> > driver need no longer construct clock names which include the PSC index,
> > remove the "psc%d_mclk" template and unconditionally use 'mclk'
> 
> Have there been other changes which make this happen?

Not yet in mainline.  The patch you respond to is 08/17 within
the series, and depends on earlier patches in the series (namely
the introduction of CCF support for the MPC512x platform, making
the 'mclk' lookup against the PSC's OF node work while keeping
the global 'pscN_mclk' in place during migration).

This information was listed in the cover letter, but was not
duplicated within the individual patches.  Patches were sent to
individual Cc: lists to not spam too many people, but the cover
letter was CC'ed to every recipient of any part of the series.

Please note that I will have to re-submit the series, since it no
longer cleanly applies against v3.13-rc1 (which was not available
when I sent v5).  This patch won't change in its content, but may
experience changes in its context (catchup with changes between
v3.12 and v3.13-rc1).

Thank you for considering the patch, and for your feedback on
past versions!


virtually yours
Gerhard Sittig
-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr. 5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-0 Fax: +49-8142-66989-80  Email: office@denx.de