| Message ID | 1442854444-4460-2-git-send-email-l.stach@pengutronix.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Sep 21, 2015 at 1:53 PM, Lucas Stach <l.stach@pengutronix.de> wrote: > Both earlycon and eralyprintk depend on the bootloader setup UART s/eralyprintk/earlyprintk > clocks being retained. This patch adds the common logic to detect such > situations and make the information available to the clock drivers, as > well as adding the facilities to disable those clocks at the end of > the kernel init. > +void __init imx_register_uart_clocks(struct clk ** const clks[]) > +{ > + if (imx_keep_uart_clocks) { > + int i; > + > + imx_uart_clocks = clks; > + for (i = 0; imx_uart_clocks[i]; i++) > + clk_prepare_enable(*imx_uart_clocks[i]); It would be better to check the return value from clk_prepare_enable() and propagate it in the case of error. > + > +static int __init imx_clk_disable_uart(void) > +{ > + if (imx_keep_uart_clocks && imx_uart_clocks) { > + int i; > + > + for (i = 0; imx_uart_clocks[i]; i++) > + clk_disable_unprepare(*imx_uart_clocks[i]); > + } > + > + return 0; This function could be made 'void' instead.
Am Montag, den 21.09.2015, 14:56 -0300 schrieb Fabio Estevam: > On Mon, Sep 21, 2015 at 1:53 PM, Lucas Stach <l.stach@pengutronix.de> wrote: > > Both earlycon and eralyprintk depend on the bootloader setup UART > > s/eralyprintk/earlyprintk > > > clocks being retained. This patch adds the common logic to detect such > > situations and make the information available to the clock drivers, as > > well as adding the facilities to disable those clocks at the end of > > the kernel init. > > > +void __init imx_register_uart_clocks(struct clk ** const clks[]) > > +{ > > + if (imx_keep_uart_clocks) { > > + int i; > > + > > + imx_uart_clocks = clks; > > + for (i = 0; imx_uart_clocks[i]; i++) > > + clk_prepare_enable(*imx_uart_clocks[i]); > > It would be better to check the return value from clk_prepare_enable() > and propagate it in the case of error. > I don't see any value of that. We certainly don't want to abort probing of the clock driver just because keeping the debug UART clocks enabled did not work. Everything in this series is about improving the debug experience, so I'm not a fan of adding code that makes it more likely to break (possibly unrelated) things. > > + > > +static int __init imx_clk_disable_uart(void) > > +{ > > + if (imx_keep_uart_clocks && imx_uart_clocks) { > > + int i; > > + > > + for (i = 0; imx_uart_clocks[i]; i++) > > + clk_disable_unprepare(*imx_uart_clocks[i]); > > + } > > + > > + return 0; > > This function could be made 'void' instead. This is an initcall, which have a fixed function prototype. Regards, Lucas
diff --git a/drivers/clk/imx/clk.c b/drivers/clk/imx/clk.c index df12b5307175..a634b1185be3 100644 --- a/drivers/clk/imx/clk.c +++ b/drivers/clk/imx/clk.c @@ -73,3 +73,41 @@ void imx_cscmr1_fixup(u32 *val) *val ^= CSCMR1_FIXUP; return; } + +static int imx_keep_uart_clocks __initdata; +static struct clk ** const *imx_uart_clocks __initdata; + +static int __init imx_keep_uart_clocks_param(char *str) +{ + imx_keep_uart_clocks = 1; + + return 0; +} +__setup_param("earlycon", imx_keep_uart_earlycon, + imx_keep_uart_clocks_param, 0); +__setup_param("earlyprintk", imx_keep_uart_earlyprintk, + imx_keep_uart_clocks_param, 0); + +void __init imx_register_uart_clocks(struct clk ** const clks[]) +{ + if (imx_keep_uart_clocks) { + int i; + + imx_uart_clocks = clks; + for (i = 0; imx_uart_clocks[i]; i++) + clk_prepare_enable(*imx_uart_clocks[i]); + } +} + +static int __init imx_clk_disable_uart(void) +{ + if (imx_keep_uart_clocks && imx_uart_clocks) { + int i; + + for (i = 0; imx_uart_clocks[i]; i++) + clk_disable_unprepare(*imx_uart_clocks[i]); + } + + return 0; +} +late_initcall_sync(imx_clk_disable_uart); diff --git a/drivers/clk/imx/clk.h b/drivers/clk/imx/clk.h index 1049b0c7d818..c94ac5c26226 100644 --- a/drivers/clk/imx/clk.h +++ b/drivers/clk/imx/clk.h @@ -7,6 +7,7 @@ extern spinlock_t imx_ccm_lock; void imx_check_clocks(struct clk *clks[], unsigned int count); +void imx_register_uart_clocks(struct clk ** const clks[]); extern void imx_cscmr1_fixup(u32 *val);
Both earlycon and eralyprintk depend on the bootloader setup UART clocks being retained. This patch adds the common logic to detect such situations and make the information available to the clock drivers, as well as adding the facilities to disable those clocks at the end of the kernel init. Signed-off-by: Lucas Stach <l.stach@pengutronix.de> --- drivers/clk/imx/clk.c | 38 ++++++++++++++++++++++++++++++++++++++ drivers/clk/imx/clk.h | 1 + 2 files changed, 39 insertions(+)