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path: root/arch/arm/mach-imx/clk-gate2.c
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* ARM: imx: fix .is_enabled() of shared gate clockShawn Guo2014-09-221-5/+1
| | | | | | | | | | | | | | | | | | | | | | | Commit 63288b721a80 ("ARM: imx: fix shared gate clock") attempted to fix an issue with particular enable/disable sequence from two shared gate clocks. But unfortunately, while it partially fixed the issue, it also did something wrong in .is_enabled() function hook. In case of shared gate, the function shouldn't really query the hardware state via share_count, because the function is trying to query the enabling state of the clock in question, not the hardware state which is shared by multiple clocks. Fix the issue by returning the enable_count of the clock itself which is maintained by clock core, in case it's a clock sharing hardware gate with others. As the result, the initialization of share_count per hardware state is not needed now. So remove it. Reported-by: Fabio Estevam <fabio.estevam@freescale.com> Fixes: 63288b721a80 ("ARM: imx: fix shared gate clock") Cc: <stable@vger.kernel.org> Signed-off-by: Shawn Guo <shawn.guo@freescale.com> Tested-by: Fabio Estevam <fabio.estevam@freescale.com> Signed-off-by: Olof Johansson <olof@lixom.net>
* ARM: imx: fix shared gate clockShawn Guo2014-07-071-8/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | Let's say clock A and B are two gate clocks that share the same register bit in hardware. Therefore they are registered as shared gate clocks with imx_clk_gate2_shared(). In a scenario that only clock A is enabled by clk_enable(A) while B is not used, the shared gate will be unexpectedly disabled in hardware. It happens because clk_enable(A) increments the share_count from 0 to 1, while clock B is unused to clock core, and therefore the core function will just disable B by calling clk->ops->disable() directly. The consequence of that call is share_count is decremented to 0 and the gate is disabled in hardware, even though clock A is still in use. The patch fixes the issue by initializing the share_count per hardware state and returns enable state per share_count from .is_enabled() hook, in case it's a shared gate. While at it, add a check in clk_gate2_disable() to ensure it's never called with a zero share_count. Reported-by: Fabio Estevam <fabio.estevam@freescale.com> Fixes: f9f28cdf2167 ("ARM: imx: add shared gate clock support") Signed-off-by: Shawn Guo <shawn.guo@freescale.com> Tested-by: Fabio Estevam <fabio.estevam@freescale.com> Signed-off-by: Olof Johansson <olof@lixom.net>
* ARM: imx: add shared gate clock supportShawn Guo2014-05-121-1/+12
| | | | | | | | | | | | | | It's quite common on i.MX that one gate bit controls the gating of multiple clocks, i.e. this is a shared gate. The patch adds the function imx_clk_gate2_shared() for such case. The clocks controlled by the same gate bits should call this function with a pointer to a single share count variable, so that the gate bits will only be operated on the first enabling and the last disabling of these shared gate clocks. Thanks to Gerhard Sittig <gsi@denx.de> for this idea. Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
* ARM: imx: lock is always valid for clk_gate2Shawn Guo2014-05-121-8/+4
| | | | | | | The imx specific clk_gate2 always has a valid lock with the clock. So the validation on gate->lock is not really needed. Remove it. Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
* ARM: imx: define struct clk_gate2 on our ownShawn Guo2014-05-121-7/+15
| | | | | | | | | | | | The imx clk-gate2 driver implements an i.MX specific gate clock, which has two bits controlling the gate states. While this is a completely separate gate driver from the common clk-gate one, it reuses the common clk_gate structure. Such reusing makes the extending of clk_gate2 clumsy. Let's define struct clk_gate2 on our own to make the driver independent of the common clk-gate one, and ease the clk_gate2 extending at a later time. Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
* ARM: imx: improve status check of clock gateAnson Huang2013-12-311-1/+1
| | | | | | | | | | | | | | For ccm clock gate, both 2b'11 and 2b'01 should be treated as clock enabled, see below description in CCM, whenver CPU trys to check clock gate's status, system will be in run mode. 2b'00: clock is off during all modes; 2b'01: clock is on in run mode, but off in wait and stop mode; 2b'10: Not applicable; 2b'11: clock is on during all modes, except stop mode. Signed-off-by: Anson Huang <b20788@freescale.com> Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
* ARM: mach-imx: clk-gate2: Include "clk.h"Fabio Estevam2013-04-011-0/+1
| | | | | | | | | Fix the following sparse warning: arch/arm/mach-imx/clk-gate2.c:86:12: warning: symbol 'clk_register_gate2' was not declared. Should it be static? Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
* ARM i.MX: fix error-valued pointer dereference in clk_register_gate2()Wei Yongjun2012-11-161-1/+1
| | | | | | | | | | | The error-valued pointer clk is used for the arg of kfree, it should be kfree(gate) if clk_register() return ERR_PTR(). dpatch engine is used to auto generate this patch. (https://github.com/weiyj/dpatch) Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
* ARM i.MX: Add common clock support for 2bit gateSascha Hauer2012-05-021-0/+118
This gate consists of two bits: 0b00: clk disabled 0b01: clk enabled in run mode and disabled in sleep mode 0b11: clk enabled Currently only disabled and enabled are supported. As it's unlikely that we find something like this in another SoC create a i.MX specific clk helper for this. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
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