RE: [PATCH 2/2] davinci: Platform support for OMAP-L137/AM17x NOR flash driver

["Savinay Dharmappa" <savinay.dharmappa@ti.com>]

Hi Sergei,

Thanks for your comments. 

On Thu, Nov 11, 2010 at 23:45:45, Sergei Shtylyov wrote:
> Hello.
> 
> Savinay Dharmappa wrote:
> 
> > From: Aleksey Makarov <amakarov@ru.mvista.com>
> 
> > Adds platform support for OMAP-L137/AM17x NOR flash driver.
> 
> > Also, configures chip select 3 to control NOR flash's upper address 
> > lines.
> 
> > Signed-off-by: Aleksey Makarov <amakarov@ru.mvista.com>
> > Signed-off-by: Savinay Dharmappa <savinay.dharmappa@ti.com>
> 
>     It's not clear why you've dropped my signoff...
> 
> >  config MACH_DAVINCI_DA850_EVM
> > diff --git a/arch/arm/mach-davinci/board-da830-evm.c 
> > b/arch/arm/mach-davinci/board-da830-evm.c
> > index 1bb89d3..c8a5d4b 100644
> > --- a/arch/arm/mach-davinci/board-da830-evm.c
> > +++ b/arch/arm/mach-davinci/board-da830-evm.c
> [...]
> > +static void da830_evm_nor_set_window(unsigned long offset, void 
> > +*data) {
> > +	/*
> > +	 * CS2 and CS3 address lines are used to address nor flash. Address
> 
>     NOR. Please be consistent.

Ok.

> 
> > +	 * line A0-A14 going to the NOR flash are latched using AEMIF
address
> > +	 * lines B_EMIF_BA0-B_EMIF_A12 on CS2. Address lines A15-A23 of the
> > +	 * NOR flash are latched using AEMIF address lines
B_EMIF_A0-B_EMIF_A6
> > +	 * on CS3. The offset argument received by this function is the
offset
> > +	 * within NOR flash. Upper address is obtained  by shifting the
offset
> > +	 * by the number of CS2 address lines used (13) and masking it with
> > +	 * complement of 3 (2 address lines used to address banks) and
adding
> > +	 * the resultant offset value to CS3 base address. Writing a zero to
> 
>     Writing anything, not just zero, I guess...
> 

I'll check this.

> > +	 * this address will latch the upper address lines.
> > +	 */
> > +	writeb(0, da830_evm_nor.latch.addr +
> > +		(~3UL & (offset >> (NOR_WINDOW_SIZE_LOG2 - 2)))); }
> 
> [...]
> 
> > +static int da830_evm_nor_init(void *data, int cs) {
> > +	/* Turn on AEMIF clocks */
> > +	da830_evm_nor.clk = clk_get(NULL, "aemif");
> > +	if (IS_ERR(da830_evm_nor.clk)) {
> > +		pr_err("%s: could not get AEMIF clock\n", __func__);
> > +		da830_evm_nor.clk = NULL;
> > +		return -ENODEV;
> > +	}
> > +	clk_enable(da830_evm_nor.clk);
> > +
> > +	da830_evm_nor.aemif.res = request_mem_region(DA8XX_AEMIF_CTL_BASE,
> > +						     SZ_32K, "AEMIF
control");
> > +	if (da830_evm_nor.aemif.res == NULL) {
> > +		pr_err("%s: could not request AEMIF control region\n",
> > +			__func__);
> > +		goto err_clk;
> > +	}
> > +
> > +	da830_evm_nor.aemif.addr = ioremap_nocache(DA8XX_AEMIF_CTL_BASE,
> > +						   SZ_32K);
> > +	if (da830_evm_nor.aemif.addr == NULL) {
> > +		pr_err("%s: could not remap AEMIF control region\n",
__func__);
> > +		goto err_aemif_region;
> > +	}
> > +
> > +	/* Setup AEMIF -- timings, etc. */
> > +
> > +	/* Set maximum wait cycles */
> > +	davinci_aemif_setup_timing(&da830_evm_norflash_timing,
> > +						da830_evm_nor.aemif.addr,
cs);
> > +
> > +	davinci_aemif_setup_timing(&da830_evm_norflash_timing,
> > +					da830_evm_nor.aemif.addr, cs + 1);
> > +
> > +	/* Setup the window to access the latch */
> > +	da830_evm_nor.latch.res =
> > +		request_mem_region(DA8XX_AEMIF_CS3_BASE, PAGE_SIZE,
> > +				   "DA830 UI NOR address latch");
> > +	if (da830_evm_nor.latch.res == NULL) {
> > +		pr_err("%s: could not request address latch region\n",
> > +			__func__);
> > +		goto err_aemif_ioremap;
> > +	}
> > +
> > +	da830_evm_nor.latch.addr =
> > +		ioremap_nocache(DA8XX_AEMIF_CS3_BASE, PAGE_SIZE);
> > +	if (da830_evm_nor.latch.addr == NULL) {
> > +		pr_err("%s: could not remap address latch region\n",
__func__);
> > +		goto err_latch_region;
> > +	}
> > +	return 0;
> > +
> > +err_latch_region:
> > +	release_mem_region(DA8XX_AEMIF_CS3_BASE, PAGE_SIZE);
> > +	da830_evm_nor.latch.res = NULL;
> 
>    This assignment is pointless.

I'll remove all such unnecessary assignments.

> 
> > +err_aemif_ioremap:
> > +	iounmap(da830_evm_nor.aemif.addr);
> > +	da830_evm_nor.aemif.addr = NULL;
> 
>     This one likewise...
> 
> > +err_aemif_region:
> > +	release_mem_region(DA8XX_AEMIF_CTL_BASE, SZ_32K);
> > +	da830_evm_nor.aemif.res = NULL;
> 
>     And this one too...
> 
> > +err_clk:
> > +	clk_disable(da830_evm_nor.clk);
> > +	clk_put(da830_evm_nor.clk);
> > +	da830_evm_nor.clk  = NULL;
> 
>     This one as well...
> 
> > +static inline void da830_evm_init_nor(int mux_mode) {
> > +	int ret;
> > +
> > +	if (HAS_MMC) {
> > +		pr_warning("WARNING: both MMC/SD and NOR are "
> > +				"enabled, but they share AEMIF pins.\n"
> > +					"\tDisable MMC/SD for NOR
support.\n");
> > +		return;
> > +	}
> > +
> > +	ret = davinci_cfg_reg_list(da830_evm_emif25_pins);
> > +	if (ret)
> > +		pr_warning("da830_evm_init: emif25 mux setup failed: %d\n",
> 
>    It's called EMIF 2.5, not "emif25".

Ok. I'll post the updated version soon.

Regards,
Savinay.