lkml.org 
[lkml]   [2019]   [Jan]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 3/3] phy: ti: Add a new SERDES driver for TI's AM654x SoC
From
Date
Hi Roger,

On 21/01/19 4:41 PM, Kishon Vijay Abraham I wrote:
> Hi Roger,
>
> On 21/01/19 3:17 PM, Roger Quadros wrote:
>> Hi Kishon,
>>
>> On 21/01/19 08:48, Kishon Vijay Abraham I wrote:
>>> Add a new SERDES driver for TI's AM654x SoC which configures
>>> the SERDES only for PCIe. Support fo USB3 will be added later.
>>>
>>> SERDES in am654x has three input clocks (left input, externel reference
>>> clock and right input) and two output clocks (left output and right
>>> output) in addition to a PLL mux clock which the SERDES uses for Clock
>>> Multiplier Unit (CMU refclock).
>>>
>>> The PLL mux clock can select from one of the three input clocks.
>>> The right output can select between left input and external reference
>>> clock while the left output can select between the right input and
>>> external reference clock.
>>>
>>> The driver has support to select PLL mux and left/right output mux as
>>> specified in device tree.
>>>
>>> [rogerq@ti.com: Fix boot lockup caused by accessing a structure member
>>> (hw->init) allocated in stack of probe() and accessed in get_parent]
>>> [rogerq@ti.com: Fix "Failed to find the parent" warnings]
>>> Signed-off-by: Roger Quadros <rogerq@ti.com>
>>> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
>>> ---
>>> drivers/phy/ti/Kconfig | 11 +
>>> drivers/phy/ti/Makefile | 1 +
>>> drivers/phy/ti/phy-am654-serdes.c | 528 ++++++++++++++++++++++++++++++
>>> 3 files changed, 540 insertions(+)
>>> create mode 100644 drivers/phy/ti/phy-am654-serdes.c
>>>
>>> diff --git a/drivers/phy/ti/Kconfig b/drivers/phy/ti/Kconfig
>>> index f137e0107764..6357c32de115 100644
>>> --- a/drivers/phy/ti/Kconfig
>>> +++ b/drivers/phy/ti/Kconfig
>>> @@ -20,6 +20,17 @@ config PHY_DM816X_USB
>>> help
>>> Enable this for dm816x USB to work.
>>>
>>> +config PHY_AM654_SERDES
>>> + tristate "TI AM654 SERDES support"
>>> + depends on OF && ARCH_K3 || COMPILE_TEST
>>> + select GENERIC_PHY
>>> + select MULTIPLEXER
>>> + select REGMAP_MMIO
>>> + select MUX_MMIO
>>> + help
>>> + This option enables support for TI AM654 SerDes PHY used for
>>> + PCIe.
>>> +
>>> config OMAP_CONTROL_PHY
>>> tristate "OMAP CONTROL PHY Driver"
>>> depends on ARCH_OMAP2PLUS || COMPILE_TEST
>>> diff --git a/drivers/phy/ti/Makefile b/drivers/phy/ti/Makefile
>>> index bea8f25a137a..bff901eb0ecc 100644
>>> --- a/drivers/phy/ti/Makefile
>>> +++ b/drivers/phy/ti/Makefile
>>> @@ -6,4 +6,5 @@ obj-$(CONFIG_OMAP_USB2) += phy-omap-usb2.o
>>> obj-$(CONFIG_TI_PIPE3) += phy-ti-pipe3.o
>>> obj-$(CONFIG_PHY_TUSB1210) += phy-tusb1210.o
>>> obj-$(CONFIG_TWL4030_USB) += phy-twl4030-usb.o
>>> +obj-$(CONFIG_PHY_AM654_SERDES) += phy-am654-serdes.o
>>> obj-$(CONFIG_PHY_TI_GMII_SEL) += phy-gmii-sel.o
>>> diff --git a/drivers/phy/ti/phy-am654-serdes.c b/drivers/phy/ti/phy-am654-serdes.c
>>> new file mode 100644
>>> index 000000000000..fcc0a98fbbd3
>>> --- /dev/null
>>> +++ b/drivers/phy/ti/phy-am654-serdes.c
>>> @@ -0,0 +1,528 @@
>>> +// SPDX-License-Identifier: GPL-2.0
>>> +/**
>>> + * PCIe SERDES driver for AM654x SoC
>>> + *
>>> + * Copyright (C) 2018 Texas Instruments
>>> + * Author: Kishon Vijay Abraham I <kishon@ti.com>
>>> + */
>>> +
>>> +#include <dt-bindings/phy/phy.h>
>>> +#include <linux/clk.h>
>>> +#include <linux/clk-provider.h>
>>> +#include <linux/delay.h>
>>> +#include <linux/io.h>
>>> +#include <linux/module.h>
>>> +#include <linux/mux/consumer.h>
>>> +#include <linux/of_address.h>
>>> +#include <linux/of_device.h>
>>> +#include <linux/phy/phy.h>
>>> +#include <linux/platform_device.h>
>>> +#include <linux/pm_runtime.h>
>>> +#include <linux/regmap.h>
>>> +#include <linux/slab.h>
>>> +#include <linux/mfd/syscon.h>
>>> +
>>> +#define CMU_R07C 0x7c
>>> +#define CMU_MASTER_CDN_O BIT(24)
>>> +
>>> +#define COMLANE_R138 0xb38
>>> +#define CONFIG_VERSION_REG_MASK GENMASK(23, 16)
>>> +#define CONFIG_VERSION_REG_SHIFT 16
>>> +#define VERSION 0x70
>>> +
>>> +#define COMLANE_R190 0xb90
>>> +#define L1_MASTER_CDN_O BIT(9)
>>> +
>>> +#define COMLANE_R194 0xb94
>>> +#define CMU_OK_I_0 BIT(19)
>>> +
>>> +#define SERDES_CTRL 0x1fd0
>>> +#define POR_EN BIT(29)
>>> +
>>> +#define WIZ_LANEXCTL_STS 0x1fe0
>>> +#define TX0_ENABLE_OVL BIT(31)
>>> +#define TX0_ENABLE_MASK GENMASK(30, 29)
>>> +#define TX0_ENABLE_SHIFT 29
>>> +#define TX0_DISABLE_STATE 0x0
>>> +#define TX0_SLEEP_STATE 0x1
>>> +#define TX0_SNOOZE_STATE 0x2
>>> +#define TX0_ENABLE_STATE 0x3
>>> +#define RX0_ENABLE_OVL BIT(15)
>>> +#define RX0_ENABLE_MASK GENMASK(14, 13)
>>> +#define RX0_ENABLE_SHIFT 13
>>> +#define RX0_DISABLE_STATE 0x0
>>> +#define RX0_SLEEP_STATE 0x1
>>> +#define RX0_SNOOZE_STATE 0x2
>>> +#define RX0_ENABLE_STATE 0x3
>>> +
>>> +#define WIZ_PLL_CTRL 0x1ff4
>>> +#define PLL_ENABLE_OVL BIT(31)
>>> +#define PLL_ENABLE_MASK GENMASK(30, 29)
>>> +#define PLL_ENABLE_SHIFT 29
>>> +#define PLL_DISABLE_STATE 0x0
>>> +#define PLL_SLEEP_STATE 0x1
>>> +#define PLL_SNOOZE_STATE 0x2
>>> +#define PLL_ENABLE_STATE 0x3
>>> +#define PLL_OK BIT(28)
>>> +
>>> +#define PLL_LOCK_TIME 100000 /* in microseconds */
>>> +#define SLEEP_TIME 100 /* in microseconds */
>>> +
>>> +#define LANE_USB3 0x0
>>> +#define LANE_PCIE0_LANE0 0x1
>>> +
>>> +#define LANE_PCIE1_LANE0 0x0
>>> +#define LANE_PCIE0_LANE1 0x1
>>> +
>>> +#define SERDES_NUM_CLOCKS 3
>>> +
>>> +struct serdes_am654_clk_mux {
>>> + struct clk_hw hw;
>>> + struct regmap *regmap;
>>> + unsigned int reg;
>>> + int *table;
>>> + u32 mask;
>>> + u8 shift;
>>> + struct clk_init_data clk_data;
>>> +};
>>> +
>>> +#define to_serdes_am654_clk_mux(_hw) \
>>> + container_of(_hw, struct serdes_am654_clk_mux, hw)
>>> +
>>> +static struct regmap_config serdes_am654_regmap_config = {
>>> + .reg_bits = 32,
>>> + .val_bits = 32,
>>> + .reg_stride = 4,
>>> + .fast_io = true,
>>> +};
>>> +
>>> +struct serdes_am654 {
>>> + struct regmap *regmap;
>>> + struct device *dev;
>>> + struct mux_control *control;
>>> + bool busy;
>>> + u32 type;
>>> + struct device_node *of_node;
>>> + struct clk_onecell_data clk_data;
>>> + struct clk *clks[SERDES_NUM_CLOCKS];
>>> +};
>>> +
>>> +static int serdes_am654_enable_pll(struct serdes_am654 *phy)
>>> +{
>>> + u32 mask = PLL_ENABLE_OVL | PLL_ENABLE_MASK;
>>> + u32 val = PLL_ENABLE_OVL | (PLL_ENABLE_STATE << PLL_ENABLE_SHIFT);
>>> +
>>> + regmap_update_bits(phy->regmap, WIZ_PLL_CTRL, mask, val);
>>> +
>>> + return regmap_read_poll_timeout(phy->regmap, WIZ_PLL_CTRL, val,
>>> + val & PLL_OK, 1000, PLL_LOCK_TIME);
>>> +}
>>> +
>>> +static void serdes_am654_disable_pll(struct serdes_am654 *phy)
>>> +{
>>> + u32 mask = PLL_ENABLE_OVL | PLL_ENABLE_MASK;
>>> +
>>> + regmap_update_bits(phy->regmap, WIZ_PLL_CTRL, mask, 0);
>>
>> Shouldn't PLL_ENABLE_OVL be left set otherwise override mechanism won't work?
>
> I have to check this.

You are right, PLL_ENABLE_OVL should be set.

Thanks
Kishon

>>
>> So,
>>
>> regmap_update_bits(phy->regmap, WIZ_PLL_CTRL, mask, PLL_ENABLE_OVL);
>>
>>> +}
>>> +
>>> +static int serdes_am654_enable_txrx(struct serdes_am654 *phy)
>>> +{
>>> + u32 mask;
>>> + u32 val;
>>> +
>>> + /* Enable TX */
>>> + mask = TX0_ENABLE_OVL | TX0_ENABLE_MASK;
>>> + val = TX0_ENABLE_OVL | (TX0_ENABLE_STATE << TX0_ENABLE_SHIFT);
>>> + regmap_update_bits(phy->regmap, WIZ_LANEXCTL_STS, mask, val);
>>> +
>>> + /* Enable RX */
>>> + mask = RX0_ENABLE_OVL | RX0_ENABLE_MASK;
>>> + val = RX0_ENABLE_OVL | (RX0_ENABLE_STATE << RX0_ENABLE_SHIFT);
>>> + regmap_update_bits(phy->regmap, WIZ_LANEXCTL_STS, mask, val);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int serdes_am654_disable_txrx(struct serdes_am654 *phy)
>>> +{
>>> + u32 mask;
>>> +
>>> + /* Disable TX */
>>> + mask = TX0_ENABLE_OVL | TX0_ENABLE_MASK;
>>> + regmap_update_bits(phy->regmap, WIZ_LANEXCTL_STS, mask, 0);
>>
>> Here too.
>>> +
>>> + /* Disable RX */
>>> + mask = RX0_ENABLE_OVL | RX0_ENABLE_MASK;
>>> + regmap_update_bits(phy->regmap, WIZ_LANEXCTL_STS, mask, 0);
>>
>> Here as well.
>>
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int serdes_am654_power_on(struct phy *x)
>>> +{
>>> + struct serdes_am654 *phy = phy_get_drvdata(x);
>>> + struct device *dev = phy->dev;
>>> + int ret;
>>> + u32 val;
>>> +
>>> + ret = serdes_am654_enable_pll(phy);
>>> + if (ret) {
>>> + dev_err(dev, "Failed to enable PLL\n");
>>> + return ret;
>>> + }
>>> +
>>> + ret = serdes_am654_enable_txrx(phy);
>>> + if (ret) {
>>> + dev_err(dev, "Failed to enable TX RX\n");
>>> + return ret;
>>> + }
>>> +
>>> + return regmap_read_poll_timeout(phy->regmap, COMLANE_R194, val,
>>> + val & CMU_OK_I_0, SLEEP_TIME,
>>> + PLL_LOCK_TIME);
>>> +}
>>> +
>>> +static int serdes_am654_power_off(struct phy *x)
>>> +{
>>> + struct serdes_am654 *phy = phy_get_drvdata(x);
>>> +
>>> + serdes_am654_disable_txrx(phy);
>>> + serdes_am654_disable_pll(phy);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int serdes_am654_init(struct phy *x)
>>> +{
>>> + struct serdes_am654 *phy = phy_get_drvdata(x);
>>> + u32 mask;
>>> + u32 val;
>>> +
>>> + mask = CONFIG_VERSION_REG_MASK;
>>> + val = VERSION << CONFIG_VERSION_REG_SHIFT;
>>> + regmap_update_bits(phy->regmap, COMLANE_R138, mask, val);
>>> +
>>> + val = CMU_MASTER_CDN_O;
>>> + regmap_update_bits(phy->regmap, CMU_R07C, val, val);
>>> +
>>> + val = L1_MASTER_CDN_O;
>>> + regmap_update_bits(phy->regmap, COMLANE_R190, val, val);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int serdes_am654_reset(struct phy *x)
>>> +{
>>> + struct serdes_am654 *phy = phy_get_drvdata(x);
>>> + u32 val;
>>> +
>>> + val = POR_EN;
>>> + regmap_update_bits(phy->regmap, SERDES_CTRL, val, val);
>>> + mdelay(1);
>>> + regmap_update_bits(phy->regmap, SERDES_CTRL, val, 0);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +struct phy *serdes_am654_xlate(struct device *dev, struct of_phandle_args
>>> + *args)
>>> +{
>>> + struct serdes_am654 *am654_phy;
>>> + struct phy *phy;
>>> + int ret;
>>> +
>>> + phy = of_phy_simple_xlate(dev, args);
>>> + if (IS_ERR(phy))
>>> + return phy;
>>> +
>>> + am654_phy = phy_get_drvdata(phy);
>>> + if (am654_phy->type != args->args[0] && am654_phy->busy)
>>> + return ERR_PTR(-EBUSY);
>>
>> You set the busy flag in this function but it is never cleared.
>> This means the second phy_get() will always fail. We might get into this
>> situation for example if the driver doing the phy_get() had to bail out
>> due to some reason (e.g. -EPROBE_DEFER), and gets probed again and does
>> a phy_get() a second time for the same PHY and lane.
>>
>> Can we clear the busy flag and call mux_control_deselect() on phy_put()?
>
> Good point. Right now, the PHY framework doesn't have a callback to the PHY
> drivers on phy_put. Looks like we might have to add it for this scenario.
>
> Thanks
> Kishon
>

\
 
 \ /
  Last update: 2019-01-23 13:21    [W:0.089 / U:0.692 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site