RE: [RFC 08/47] mtd: nand: stm_nand_bch: supply clock support

Gupta, Pekon
2014-03-26T07:15:55Z

>From: Lee Jones [mailto:lee.jones@linaro.org]
>
>Add support for clocks when, and only when, they are supplied. It is
>not yet compulsory to provide the BCH and EMI clocks, as Common Clk isn't
>supported Mainline yet. Until an implementation lands upstream all clocks
>located on STM boards default to always-on.
>
Good to put this information in comments tagged with "FixMe" at relevant place in the code.

>Signed-off-by: Lee Jones <lee.jones@linaro.org>
>---
> drivers/mtd/nand/stm_nand_bch.c | 49 +++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 49 insertions(+)
>
>diff --git a/drivers/mtd/nand/stm_nand_bch.c b/drivers/mtd/nand/stm_nand_bch.c
>index 1a93f8d..cc0159e 100644
>--- a/drivers/mtd/nand/stm_nand_bch.c
>+++ b/drivers/mtd/nand/stm_nand_bch.c
>@@ -16,6 +16,7 @@
> #include <linux/module.h>
> #include <linux/delay.h>
> #include <linux/io.h>
>+#include <linux/clk.h>
> #include <linux/interrupt.h>
> #include <linux/device.h>
> #include <linux/platform_device.h>
>@@ -28,6 +29,9 @@
> struct nandi_controller {
> void __iomem *base; /* Controller base*/
> void __iomem *dma; /* DMA control base */
>+
>+ struct clk *bch_clk;
>+ struct clk *emi_clk;
> /* IRQ-triggered Completions: */
> struct completion seq_completed; /* SEQ Over */
> struct completion rbn_completed; /* RBn */
>@@ -103,6 +107,44 @@ static void nandi_disable_interrupts(struct nandi_controller *nandi,
> writel(val, nandi->base + NANDBCH_INT_EN);
> }
>
>+static void nandi_clk_enable(struct nandi_controller *nandi)
>+{
>+ if (nandi->emi_clk)
>+ clk_prepare_enable(nandi->emi_clk);
>+ if (nandi->bch_clk)
>+ clk_prepare_enable(nandi->bch_clk);
>+}
>+
You are using nandi_clk_enable() only in your PM patch.
So better introduce above functions there ..
[RFC 11/47] mtd: nand: stm_nand_bch: add Power Management

Also, you have some un-related comment changes for nandi_clk_enable()
in below patch. All that can be merges into single one.
[RFC 14/47] mtd: nand: stm_nand_bch: configure BCH and FLEX by ONFI timing mode

>+static void nandi_clk_disable(struct nandi_controller *nandi)
>+{
>+ if (nandi->emi_clk)
>+ clk_disable_unprepare(nandi->emi_clk);
>+ if (nandi->bch_clk)
>+ clk_disable_unprepare(nandi->bch_clk);
>+}
>+
same, please move this to
[RFC 11/47] mtd: nand: stm_nand_bch: add Power Management

Also as Ezequiel suggested.
You can trim down the number of patches by submitting only the main portion
of driver first. PM other features can be added as separate patch-set.

with regards, pekon