[PATCH v2 1/8] clk: imx: add common logic to detect early UART usage
From: Uwe Kleine-König <hidden>
Date: 2015-09-07 09:06:03
Also in:
linux-clk
Hello Lucas, On Fri, Sep 04, 2015 at 06:00:12PM +0200, Lucas Stach wrote:
quoted hunk ↗ jump to hunk
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 | 46 ++++++++++++++++++++++++++++++++++++++++++++++ drivers/clk/imx/clk.h | 1 + 2 files changed, 47 insertions(+)diff --git a/drivers/clk/imx/clk.c b/drivers/clk/imx/clk.c index df12b5307175..3357e29e43ab 100644 --- a/drivers/clk/imx/clk.c +++ b/drivers/clk/imx/clk.c@@ -73,3 +73,49 @@ void imx_cscmr1_fixup(u32 *val) *val ^= CSCMR1_FIXUP; return; } + +static int __initdata imx_keep_uart_clocks; +static struct clk __initdata ***imx_uart_clocks; + +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 **clks[])
const struct clk **clks[]? I wonder why you need an array of pointers to pointers of clocks. Isn't one indirection less possible and more easy?
+{
+ if (imx_keep_uart_clocks) {
+ int i;
+
+ imx_uart_clocks = clks;
+ for (i = 0;; i++) {
+ if (imx_uart_clocks[i])
+ clk_prepare_enable(*imx_uart_clocks[i]);
+ else
+ break;
+ }I would have written this as: for (i = 0; imx_uart_clocks[i]; ++i) clk_prepare_enable(*imx_uart_clocks[i]); but I guess that's a matter of taste. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-K?nig | Industrial Linux Solutions | http://www.pengutronix.de/ |