From mboxrd@z Thu Jan 1 00:00:00 1970 From: York Sun Date: Wed, 23 Apr 2014 15:02:29 -0700 Subject: [U-Boot] [PATCH][v2] driver/net/fm/memac_phy: Initialize mdio_clock for SoCs wih FMANv3 In-Reply-To: <1396934749-2282-1-git-send-email-Priyanka.Jain@freescale.com> References: <1396934749-2282-1-git-send-email-Priyanka.Jain@freescale.com> Message-ID: <53583875.6000603@freescale.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 04/07/2014 10:25 PM, Priyanka Jain wrote: > MDIO clock needs to be initialized in u-boot code for SoCs > having FMAN-v3(v3H or v3L) controller due to below reasons > > -On SoCs that have FMAN-v3H like B4860, default value of > MDIO_CLK_DIV bits in mdio_stat(mdio_cfg) register generates > mdio clock too high (much higher than 2.5MHz), violating the > IEEE specs. > -On SOCs that have FMAN-v3L like T1040, default value of > MDIO_CLK_DIV bits is zero, so MDIO clock is disabled. > > So, for proper functioninig of MDIO, MDIO_CLK_DIV bits needs to > be properly initialized. > Also this type of initialization is generally done in > PBI(pre-bootloader) phase using rcw.But for chips like T1040 > which support deep-sleep, such type of initialization cannot be > done in PBI phase due to the limitation that during deep-sleep > resume, FMAN (MDIO) registers are not accessible in PBI phase. > So, mdio clock initailization must be done as part of u-boot. > > This initialization code is implemented in memac_phy.c which > gets compiled only for SoCs having FMANv3, so no extra compilation > flag is required. > > Signed-off-by: Priyanka Jain > --- > Changes for v2: Corrected Signed-off footer > Applied to u-boot-mpc85xx/master, thanks. York