Re: [PATCH 3/3] phy: ulpi: add driver for TI TUSB1210

From: Felipe Balbi
Date: Tue Jan 20 2015 - 10:46:35 EST


Hi,

On Tue, Jan 20, 2015 at 11:18:22AM +0200, Heikki Krogerus wrote:
> TUSB1210 ULPI PHY has vendor specific register for eye
> diagram tuning. On some platforms the system firmware has
> set optimized value to it. In order to not loose the
> optimized value, the driver stores it during probe and
> restores it every time the PHY is powered back on.
>
> Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> ---
> drivers/phy/ulpi/Kconfig | 11 ++++
> drivers/phy/ulpi/Makefile | 2 +
> drivers/phy/ulpi/tusb1210.c | 131 ++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 144 insertions(+)
> create mode 100644 drivers/phy/ulpi/tusb1210.c
>
> diff --git a/drivers/phy/ulpi/Kconfig b/drivers/phy/ulpi/Kconfig
> index 8007df2..7cd6f82 100644
> --- a/drivers/phy/ulpi/Kconfig
> +++ b/drivers/phy/ulpi/Kconfig
> @@ -7,3 +7,14 @@ config ULPI_PHY
> Say yes if you have ULPI PHY attached to your USB controller.
>
> If unsure, say N.
> +
> +if ULPI_PHY
> +
> +config ULPI_TUSB1210
> + tristate "TI TUSB1210 USB PHY module"
> + depends on POWER_SUPPLY
> + select USB_PHY
> + help
> + Support for TI TUSB1210 USB ULPI PHY.
> +
> +endif
> diff --git a/drivers/phy/ulpi/Makefile b/drivers/phy/ulpi/Makefile
> index 59e61cb..7ee6679 100644
> --- a/drivers/phy/ulpi/Makefile
> +++ b/drivers/phy/ulpi/Makefile
> @@ -1,2 +1,4 @@
> ulpiphy-y := ulpi.o
> obj-$(CONFIG_ULPI_PHY) += ulpiphy.o
> +
> +obj-$(CONFIG_ULPI_TUSB1210) += tusb1210.o
> diff --git a/drivers/phy/ulpi/tusb1210.c b/drivers/phy/ulpi/tusb1210.c
> new file mode 100644
> index 0000000..ac77f98
> --- /dev/null
> +++ b/drivers/phy/ulpi/tusb1210.c

do you really need this extra ulpi directory ?

I wonder if phy-tusb1210.c as a name would be enough.

> @@ -0,0 +1,131 @@
> +/**
> + * tusb1210.c - TUSB1210 USB ULPI PHY driver
> + *
> + * Copyright (C) 2015 Intel Corporation
> + *
> + * Author: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +#include <linux/module.h>
> +#include <linux/phy/ulpi/driver.h>
> +#include <linux/phy/ulpi/regs.h>
> +#include <linux/gpio/consumer.h>
> +
> +#include "ulpi_phy.h"
> +
> +struct tusb1210 {
> + struct ulpi *ulpi;
> + struct phy *phy;
> + struct gpio_desc *gpio_reset;
> + struct gpio_desc *gpio_cs;
> + u8 ctx[1];
> +};
> +
> +static int tusb1210_power_on(struct phy *phy)
> +{
> + struct tusb1210 *tusb = phy_get_drvdata(phy);
> +
> + gpiod_set_value_cansleep(tusb->gpio_reset, 1);
> + gpiod_set_value_cansleep(tusb->gpio_cs, 1);
> +
> + /* Restore eye optimisation value */
> + ulpi_write(tusb->ulpi, ULPI_EXT_VENDOR_SPECIFIC, tusb->ctx[0]);
> +
> + return 0;
> +}
> +
> +static int tusb1210_power_off(struct phy *phy)
> +{
> + struct tusb1210 *tusb = phy_get_drvdata(phy);
> +
> + gpiod_set_value_cansleep(tusb->gpio_reset, 0);
> + gpiod_set_value_cansleep(tusb->gpio_cs, 0);
> +
> + return 0;
> +}
> +
> +static struct phy_ops phy_ops = {
> + .power_on = tusb1210_power_on,
> + .power_off = tusb1210_power_off,
> + .init = tusb1210_power_on,
> + .exit = tusb1210_power_off,
> + .owner = THIS_MODULE,
> +};
> +
> +static int tusb1210_probe(struct ulpi *ulpi)
> +{
> + struct gpio_desc *gpio;
> + struct tusb1210 *tusb;
> + int ret;
> +
> + tusb = devm_kzalloc(&ulpi->dev, sizeof(*tusb), GFP_KERNEL);
> + if (!tusb)
> + return -ENOMEM;
> +
> + gpio = devm_gpiod_get(&ulpi->dev, "reset");
> + if (!IS_ERR(gpio)) {
> + ret = gpiod_direction_output(gpio, 0);
> + if (ret)
> + return ret;
> + tusb->gpio_reset = gpio;
> + }
> +
> + gpio = devm_gpiod_get(&ulpi->dev, "cs");
> + if (!IS_ERR(gpio)) {
> + ret = gpiod_direction_output(gpio, 0);
> + if (ret)
> + return ret;
> + tusb->gpio_cs = gpio;
> + }
> +
> + /* Store initial eye diagram optimisation value */
> + ret = ulpi_read(ulpi, ULPI_EXT_VENDOR_SPECIFIC);

do they *all* use this register for eye diagram optimization or is this
something that Intel decided to do ?

(sorry, don't know much about tusb1210 other than it sucks like hell :-)

> + if (ret < 0)
> + return ret;
> +
> + tusb->ctx[0] = ret;
> +
> + tusb->phy = ulpi_phy_create(ulpi, &phy_ops);
> + if (IS_ERR(tusb->phy))
> + return PTR_ERR(tusb->phy);
> +
> + tusb->ulpi = ulpi;
> +
> + phy_set_drvdata(tusb->phy, tusb);
> + dev_set_drvdata(&ulpi->dev, tusb);
> + return 0;
> +}
> +
> +static void tusb1210_remove(struct ulpi *ulpi)
> +{
> + struct tusb1210 *tusb = dev_get_drvdata(&ulpi->dev);

completely unrelated to $subject, but we might want to have a
ulpi_{set,get}_drvdata() at some point.

In fact, we might decide to add an entire ULPI bus, eventually, though
I'm still considering if there's any benefit to that.

> +
> + ulpi_phy_destroy(ulpi, tusb->phy);
> +}
> +
> +#define TI_VENDOR_ID 0x0451
> +
> +static struct ulpi_device_id tusb1210_ulpi_id[] = {
> + { TI_VENDOR_ID, 0x1508, },
> + { },
> +};
> +MODULE_DEVICE_TABLE(ulpi, tusb1210_ulpi_id);
> +
> +static struct ulpi_driver tusb1210_driver = {
> + .id_table = tusb1210_ulpi_id,
> + .probe = tusb1210_probe,
> + .remove = tusb1210_remove,
> + .driver = {
> + .name = "tusb1210",
> + .owner = THIS_MODULE,
> + },
> +};
> +
> +module_ulpi_driver(tusb1210_driver);
> +
> +MODULE_AUTHOR("Intel Corporation");
> +MODULE_LICENSE("GPL");

comment says GPL 2 only, this says GPL 2+

--
balbi

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