RE: [RFC 07/47] mtd: nand: stm_nand_bch: initialise the BCH Controller

Gupta, Pekon
2014-03-26T10:25:52Z

Hi Lee,

>From: Lee Jones [mailto:lee.jones@linaro.org]
missing commit log :-)
Though $subject is self-explanatory, but you can add more description about
assumption and hardware caveats about the controller, and its use.

>
>Signed-off-by: Lee Jones <lee.jones@linaro.org>
>---
> drivers/mtd/nand/stm_nand_bch.c | 56 +++++++++++++++++++++++++++++++++++++++++
> include/linux/mtd/stm_nand.h | 20 +++++++++++++++
> 2 files changed, 76 insertions(+)
>
>diff --git a/drivers/mtd/nand/stm_nand_bch.c b/drivers/mtd/nand/stm_nand_bch.c
>index 76a0d02..1a93f8d 100644
>--- a/drivers/mtd/nand/stm_nand_bch.c
>+++ b/drivers/mtd/nand/stm_nand_bch.c
>@@ -14,6 +14,7 @@
>
> #include <linux/kernel.h>
> #include <linux/module.h>
>+#include <linux/delay.h>
> #include <linux/io.h>
> #include <linux/interrupt.h>
> #include <linux/device.h>
>@@ -102,6 +103,56 @@ static void nandi_disable_interrupts(struct nandi_controller *nandi,
> writel(val, nandi->base + NANDBCH_INT_EN);
> }
>
>+static void nandi_init_bch(struct nandi_controller *nandi, int emi_bank)
>+{
>+ dev_dbg(nandi->dev, "%s\n", __func__);
>+
>+ /* Initialise BCH Controller */
>+ emiss_nandi_select(STM_NANDI_BCH);
>+
>+ /* Reset and disable boot-mode controller */
>+ writel(BOOT_CFG_RESET, nandi->base + NANDBCH_BOOTBANK_CFG);
>+ udelay(1);
>+ writel(0x00000000, nandi->base + NANDBCH_BOOTBANK_CFG);

Why using 'udelay' ?
Isn't there any status register which tells you that controller is reset / initialized ?
Or may be polling on NANDBCH_BOOTBANK_CFG may itself give you status.

>+
>+ /* Reset AFM controller */
>+ writel(CFG_RESET, nandi->base + NANDBCH_CONTROLLER_CFG);
>+ udelay(1);
>+ writel(0x00000000, nandi->base + NANDBCH_CONTROLLER_CFG);
>+
>+ /* Set EMI Bank */
>+ writel(0x1 << emi_bank, nandi->base + NANDBCH_FLEX_MUXCTRL);
>+
>+ /* Reset ECC stats */
>+ writel(0x7f0, nandi->base + NANDBCH_CONTROLLER_CFG);
>+ udelay(1);
>+
"0x7f0" ?? please use Macro instead.

with regards, pekon