Re: [PATCH v3 4/5] phy: add Broadcom SATA3 PHY driver for Broadcom STB SoCs

[Kishon Vijay Abraham I <kishon@ti.com>]

Hi,

On Thursday 14 May 2015 12:19 AM, Brian Norris wrote:
> On Wed, May 13, 2015 at 04:37:05PM +0530, Kishon Vijay Abraham I wrote:
>> Hi,
>>
>> On Wednesday 13 May 2015 04:58 AM, Brian Norris wrote:
>>> Supports up to two ports which can each be powered on/off and configured
>>> independently.
>>>
>>> Signed-off-by: Brian Norris <computersforpeace@gmail.com>
>>
>> couple of minor comments below
>>> ---
>>> v3: no change
>>>
>>> v2:
>>>    - stop sharing SATA_TOP_CTRL registers with SATA driver
>>>    - kill custom xlate function
>>>
>>>   drivers/phy/Kconfig            |   9 ++
>>>   drivers/phy/Makefile           |   1 +
>>>   drivers/phy/phy-brcmstb-sata.c | 216 +++++++++++++++++++++++++++++++++++++++++
>>>   3 files changed, 226 insertions(+)
>>>   create mode 100644 drivers/phy/phy-brcmstb-sata.c
>>>
>>> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
>>> index a53bd5b52df9..36788b6f0220 100644
>>> --- a/drivers/phy/Kconfig
>>> +++ b/drivers/phy/Kconfig
>>> @@ -309,4 +309,13 @@ config PHY_QCOM_UFS
>>>   	help
>>>   	  Support for UFS PHY on QCOM chipsets.
>>>
>>> +config PHY_BRCMSTB_SATA
>>> +	tristate "Broadcom STB SATA PHY driver"
>>> +	depends on ARCH_BRCMSTB
>>> +	depends on OF
>>> +	select GENERIC_PHY
>>> +	help
>>> +	  Enable this to support the SATA3 PHY on 28nm Broadcom STB SoCs.
>>> +	  Likely useful only with CONFIG_SATA_BRCMSTB enabled.
>>> +
>>>   endmenu
>>> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
>>> index f12625178780..c61f3fdd191e 100644
>>> --- a/drivers/phy/Makefile
>>> +++ b/drivers/phy/Makefile
>>> @@ -40,3 +40,4 @@ obj-$(CONFIG_PHY_STIH41X_USB)		+= phy-stih41x-usb.o
>>>   obj-$(CONFIG_PHY_QCOM_UFS) 	+= phy-qcom-ufs.o
>>>   obj-$(CONFIG_PHY_QCOM_UFS) 	+= phy-qcom-ufs-qmp-20nm.o
>>>   obj-$(CONFIG_PHY_QCOM_UFS) 	+= phy-qcom-ufs-qmp-14nm.o
>>> +obj-$(CONFIG_PHY_BRCMSTB_SATA)		+= phy-brcmstb-sata.o
>>> diff --git a/drivers/phy/phy-brcmstb-sata.c b/drivers/phy/phy-brcmstb-sata.c
>>> new file mode 100644
>>> index 000000000000..8387c8cbea8c
>>> --- /dev/null
>>> +++ b/drivers/phy/phy-brcmstb-sata.c
>>> @@ -0,0 +1,216 @@
>>> +/*
>>> + * Broadcom SATA3 AHCI Controller PHY Driver
>>> + *
>>> + * Copyright © 2009-2015 Broadcom 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, or (at your option)
>>> + * any later version.
>>> + *
>>> + * This program is distributed in the hope that it will be useful,
>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>>> + * GNU General Public License for more details.
>>> + */
>>> +
>>> +#include <linux/device.h>
>>> +#include <linux/init.h>
>>> +#include <linux/interrupt.h>
>>> +#include <linux/io.h>
>>> +#include <linux/kernel.h>
>>> +#include <linux/module.h>
>>> +#include <linux/of.h>
>>> +#include <linux/phy/phy.h>
>>> +#include <linux/platform_device.h>
>>> +
>>> +#define SATA_MDIO_BANK_OFFSET				0x23c
>>> +#define SATA_MDIO_REG_OFFSET(ofs)			((ofs) * 4)
>>> +#define SATA_MDIO_REG_SPACE_SIZE			0x1000
>>> +#define SATA_MDIO_REG_LENGTH				0x1f00
>>> +
>>> +#define MAX_PORTS					2
>>> +
>>> +/* Register offset between PHYs in PCB space */
>>> +#define SATA_MDIO_REG_SPACE_SIZE			0x1000
>>> +
>>> +struct brcm_sata_port {
>>> +	int portnum;
>>> +	struct phy *phy;
>>> +	struct brcm_sata_phy *phy_priv;
>>> +	bool ssc_en;
>>> +};
>>> +
>>> +struct brcm_sata_phy {
>>> +	struct device *dev;
>>> +	void __iomem *phy_base;
>>> +
>>> +	struct brcm_sata_port phys[MAX_PORTS];
>>> +};
>>> +
>>> +enum sata_mdio_phy_regs_28nm {
>>
>> Why should these defines be in enum?
>
> Why not? They're logically grouped this way, and IMO, they look nicer.
> You can see drivers/ata/ahci.h for a similar example.

fair enough.
>
>>> +	PLL_REG_BANK_0				= 0x50,
>>> +	PLL_REG_BANK_0_PLLCONTROL_0		= 0x81,
>>> +
>>> +	TXPMD_REG_BANK				= 0x1a0,
>>> +	TXPMD_CONTROL1				= 0x81,
>>> +	TXPMD_CONTROL1_TX_SSC_EN_FRC		= BIT(0),
>>> +	TXPMD_CONTROL1_TX_SSC_EN_FRC_VAL	= BIT(1),
>>> +	TXPMD_TX_FREQ_CTRL_CONTROL1		= 0x82,
>>> +	TXPMD_TX_FREQ_CTRL_CONTROL2		= 0x83,
>>> +	TXPMD_TX_FREQ_CTRL_CONTROL2_FMIN_MASK	= 0x3ff,
>>> +	TXPMD_TX_FREQ_CTRL_CONTROL3		= 0x84,
>>> +	TXPMD_TX_FREQ_CTRL_CONTROL3_FMAX_MASK	= 0x3ff,
>>> +};
>>> +
>>> +static inline void __iomem *brcm_sata_phy_base(struct brcm_sata_port *port)
>>> +{
>>> +	struct brcm_sata_phy *priv = port->phy_priv;
>>> +
>>> +	return priv->phy_base + (port->portnum * SATA_MDIO_REG_SPACE_SIZE);
>>> +}
>>> +
>>> +static void brcm_sata_mdio_wr(void __iomem *addr, u32 bank, u32 ofs,
>>> +			      u32 msk, u32 value)
>>> +{
>>> +	u32 tmp;
>>> +
>>> +	writel(bank, addr + SATA_MDIO_BANK_OFFSET);
>>> +	tmp = readl(addr + SATA_MDIO_REG_OFFSET(ofs));
>>> +	tmp = (tmp & msk) | value;
>>> +	writel(tmp, addr + SATA_MDIO_REG_OFFSET(ofs));
>>> +}
>>> +
>>> +/* These defaults were characterized by H/W group */
>>> +#define FMIN_VAL_DEFAULT	0x3df
>>> +#define FMAX_VAL_DEFAULT	0x3df
>>> +#define FMAX_VAL_SSC		0x83
>>> +
>>> +static void cfg_ssc_28nm(struct brcm_sata_port *port)
>>
>> brcm_sata_cfg_ssc_28nm to make it similar to other functions.
>
> OK.
>
>>> +{
>>> +	void __iomem *base = brcm_sata_phy_base(port);
>>> +	struct brcm_sata_phy *priv = port->phy_priv;
>>> +	u32 tmp;
>>> +
>>> +	/* override the TX spread spectrum setting */
>>> +	tmp = TXPMD_CONTROL1_TX_SSC_EN_FRC_VAL | TXPMD_CONTROL1_TX_SSC_EN_FRC;
>>> +	brcm_sata_mdio_wr(base, TXPMD_REG_BANK, TXPMD_CONTROL1, ~tmp, tmp);
>>> +
>>> +	/* set fixed min freq */
>>> +	brcm_sata_mdio_wr(base, TXPMD_REG_BANK, TXPMD_TX_FREQ_CTRL_CONTROL2,
>>> +			  ~TXPMD_TX_FREQ_CTRL_CONTROL2_FMIN_MASK,
>>> +			  FMIN_VAL_DEFAULT);
>>> +
>>> +	/* set fixed max freq depending on SSC config */
>>> +	if (port->ssc_en) {
>>> +		dev_info(priv->dev, "enabling SSC on port %d\n", port->portnum);
>>> +		tmp = FMAX_VAL_SSC;
>>> +	} else {
>>> +		tmp = FMAX_VAL_DEFAULT;
>>> +	}
>>> +
>>> +	brcm_sata_mdio_wr(base, TXPMD_REG_BANK, TXPMD_TX_FREQ_CTRL_CONTROL3,
>>> +			  ~TXPMD_TX_FREQ_CTRL_CONTROL3_FMAX_MASK, tmp);
>>> +}
>>> +
>>> +static int brcm_sata_phy_init(struct phy *phy)
>>> +{
>>> +	struct brcm_sata_port *port = phy_get_drvdata(phy);
>>> +
>>> +	cfg_ssc_28nm(port);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static struct phy_ops phy_ops_28nm = {
>>> +	.init		= brcm_sata_phy_init,
>>> +	.owner		= THIS_MODULE,
>>> +};
>>> +
>>> +static const struct of_device_id brcm_sata_phy_of_match[] = {
>>> +	{ .compatible	= "brcm,bcm7445-sata-phy" },
>>> +	{},
>>> +};
>>> +MODULE_DEVICE_TABLE(of, brcm_sata_phy_of_match);
>>> +
>>> +static int brcm_sata_phy_probe(struct platform_device *pdev)
>>> +{
>>> +	struct device *dev = &pdev->dev;
>>> +	struct device_node *dn = dev->of_node, *child;
>>> +	struct brcm_sata_phy *priv;
>>> +	struct resource *res;
>>> +	struct phy_provider *provider;
>>> +	int count = 0;
>>> +
>>> +	if (of_get_child_count(dn) == 0)
>>> +		return -ENODEV;
>>> +
>>> +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
>>> +	if (!priv)
>>> +		return -ENOMEM;
>>> +	dev_set_drvdata(dev, priv);
>>> +	priv->dev = dev;
>>> +
>>> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "phy");
>>> +	priv->phy_base = devm_ioremap_resource(dev, res);
>>> +	if (IS_ERR(priv->phy_base))
>>> +		return PTR_ERR(priv->phy_base);
>>> +
>>> +	for_each_available_child_of_node(dn, child) {
>>> +		unsigned int id;
>>> +		struct brcm_sata_port *port;
>>> +
>>> +		if (of_property_read_u32(child, "reg", &id)) {
>>> +			dev_err(dev, "missing reg property in node %s\n",
>>> +					child->name);
>>> +			return -EINVAL;
>>> +		}
>>> +
>>> +		if (id >= MAX_PORTS) {
>>> +			dev_err(dev, "invalid reg: %u\n", id);
>>> +			return -EINVAL;
>>> +		}
>>> +		if (priv->phys[id].phy) {
>>> +			dev_err(dev, "already registered port %u\n", id);
>>> +			return -EINVAL;
>>> +		}
>>> +
>>> +		port = &priv->phys[id];
>>> +		port->portnum = id;
>>> +		port->phy_priv = priv;
>>> +		port->phy = devm_phy_create(dev, child, &phy_ops_28nm);
>>> +		port->ssc_en = of_property_read_bool(child, "brcm,enable-ssc");
>>> +		if (IS_ERR(port->phy)) {
>>> +			dev_err(dev, "failed to create PHY\n");
>>> +			return PTR_ERR(port->phy);
>>> +		}
>>> +
>>> +		phy_set_drvdata(port->phy, port);
>>> +		count++;
>>> +	}
>>> +
>>> +	provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
>>> +	if (IS_ERR(provider)) {
>>> +		dev_err(dev, "could not register PHY provider\n");
>>> +		return PTR_ERR(provider);
>>> +	}
>>> +
>>> +	dev_info(dev, "registered %d port(s)\n", count);
>>
>> lets not make the boot noisy. Change to dev_dbg?
>
> Why? What's the harm? And I thought we discussed this already. "Noisy"
> depends on your point of view; IMO, this is important information. If
> for some reason this driver wasn't loaded or probed, we'd want to know.
> Besides, dev_dbg() requires you to fiddle with both the log level and
> the dynamic debug boot parameters just to get these informational
> messages.

so be it. While sending the next version please also add a MAINTAINERs entry 
for this driver.

Cheers
Kishon