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From: dinh.linux@gmail•com (Dinh Nguyen)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCHv2 6/6] mmc: dw_mmc: Add support DW SD/MMC driver on SOCFPGA
Date: Mon, 20 May 2013 09:40:18 -0500	[thread overview]
Message-ID: <519A35D2.4010601@gmail.com> (raw)
In-Reply-To: <20130517114607.GB3466@amd.pavel.ucw.cz>

Hi Pavel,

On 05/17/2013 06:46 AM, Pavel Machek wrote:
> Hi!
> 
>> Add platform specific functionality for the DW SD/MMC driver for
>> SoCFPGA. Move SDMMC_CMD_USE_HOLD_REG to dw_mmc.h so other platforms
>> can use this define.
> 
>> --- /dev/null
>> +++ b/drivers/mmc/host/dw_mmc-socfpga.c
>> @@ -0,0 +1,139 @@
>> +/*
>> + * Altera SoCFPGA Specific Extensions for Synopsys DW Multimedia Card Interface driver
>> + *
>> + *  Copyright (C) 2012, Samsung Electronics Co., Ltd.
>> + *  Copyright (C) 2013 Altera Corporation
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License as published by
>> + * the Free Software Foundation; either version 2 of the License, or
>> + * (at your option) any later version.
>> + *
>> + * Taken from dw_mmc_exynos.c
> 
> Actually it is   dw_mmc-exynos.c

Will fix in rev3.

> 
>> +#define SYSMGR_SDMMCGRP_CTRL_OFFSET		0x108
>> +#define DRV_CLK_PHASE_SHIFT_SEL_MASK	0x7
>> +#define SYSMGR_SDMMC_CTRL_SET(smplsel, drvsel)		\
>> +	((((drvsel) << 0) & 0x7) | (((smplsel) << 3) & 0x38))
> 
> Should SYSMGR stuff go to shared header file somewhere?
> 
>> +extern void __iomem *sys_manager_base_addr;
> 
> This is unused.

Will remove.

> 
>> +/* SOCFPGA implementation specific driver private data */
>> +struct dw_mci_socfpga_priv_data {
>> +	u8	ciu_div;
> 
> comment would be nice, something like
> /* card interface unit divisor */ ?
> 
>> +	u32	hs_timing;
> 
> /* card interface unit phase shift for RX/TX mode */
> ?

Will add comments.

> 
>> +static int dw_mci_socfpga_setup_clock(struct dw_mci *host)
>> +{
>> +	struct dw_mci_socfpga_priv_data *priv = host->priv;
>> +
>> +	clk_disable(host->ciu_clk);
>> +	regmap_write(priv->sysreg, SYSMGR_SDMMCGRP_CTRL_OFFSET, priv->hs_timing);
>> +	clk_enable(host->ciu_clk);
>> +
>> +	host->bus_hz /= (priv->ciu_div + 1);
> 
> Previous version said:
> 
> +       host->bus_hz /= priv->ciu_div;
> 
> I see you want to avoid division by zero, but this will introduce
> significant error for low divisors, right? Is divisor of 0 valid?

Divisor of 0 is not valid. Not sure what you mean my low divisos?

Thanks,
Dinh
> 
> Otherwise it looks good. Thanks,
> 									Pavel
> 

  reply	other threads:[~2013-05-20 14:40 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-05-16 19:05 [PATCHv2 1/6] ARM: socfpga: dts: Add ethernet bindings for SOCFPGA dinguyen at altera.com
2013-05-16 19:05 ` [PATCHv2 2/6] ARM: socfpga: dts: Add gate-clock bindings dinguyen at altera.com
2013-05-16 19:05 ` [PATCHv2 3/6] ARM: socfpga: Add support to gate peripheral clocks dinguyen at altera.com
2013-05-17 11:09   ` Pavel Machek
2013-05-20 14:59     ` Dinh Nguyen
2013-05-16 19:05 ` [PATCHv2 4/6] ARM: socfpga: Add syscon to be part of socfpga dinguyen at altera.com
2013-05-16 19:05 ` [PATCHv2 5/6] ARM: socfpga: dts: Add support for SD/MMC dinguyen at altera.com
2013-05-16 19:05 ` [PATCHv2 6/6] mmc: dw_mmc: Add support DW SD/MMC driver on SOCFPGA dinguyen at altera.com
2013-05-17 11:46   ` Pavel Machek
2013-05-20 14:40     ` Dinh Nguyen [this message]
2013-05-20  5:40   ` Seungwon Jeon
2013-05-20 14:47     ` Dinh Nguyen

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