phy: cadence: Add Cadence D-PHY Rx driver

The Cadence D-PHY can be configured in Tx (DSI) mode or Rx (CSI) mode.
Both modes have a different programming sequence and share little among
them. In addition, a PHY configured in Tx mode cannot be used in Rx mode
and vice versa. For this reason, create a separate driver for the Rx
mode to make it easier to read and maintain.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Link: https://lore.kernel.org/r/20220301111621.2992275-2-p.yadav@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Pratyush Yadav 2022-03-01 16:46:18 +05:30 committed by Vinod Koul
parent 7a37e890bd
commit 41d393aaea
3 changed files with 264 additions and 0 deletions

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@ -22,6 +22,14 @@ config PHY_CADENCE_DPHY
system. If M is selected, the module will be called
cdns-dphy.
config PHY_CADENCE_DPHY_RX
tristate "Cadence D-PHY Rx Support"
depends on HAS_IOMEM && OF
select GENERIC_PHY
select GENERIC_PHY_MIPI_DPHY
help
Support for Cadence D-PHY in Rx configuration.
config PHY_CADENCE_SIERRA
tristate "Cadence Sierra PHY Driver"
depends on OF && HAS_IOMEM && RESET_CONTROLLER

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@ -1,5 +1,6 @@
# SPDX-License-Identifier: GPL-2.0-only
obj-$(CONFIG_PHY_CADENCE_TORRENT) += phy-cadence-torrent.o
obj-$(CONFIG_PHY_CADENCE_DPHY) += cdns-dphy.o
obj-$(CONFIG_PHY_CADENCE_DPHY_RX) += cdns-dphy-rx.o
obj-$(CONFIG_PHY_CADENCE_SIERRA) += phy-cadence-sierra.o
obj-$(CONFIG_PHY_CADENCE_SALVO) += phy-cadence-salvo.o

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@ -0,0 +1,255 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2022 Texas Instruments Incorporated - https://www.ti.com/
*/
#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/phy/phy.h>
#include <linux/phy/phy-mipi-dphy.h>
#include <linux/platform_device.h>
#define DPHY_PMA_CMN(reg) (reg)
#define DPHY_PCS(reg) (0xb00 + (reg))
#define DPHY_ISO(reg) (0xc00 + (reg))
#define DPHY_CMN_SSM DPHY_PMA_CMN(0x20)
#define DPHY_CMN_RX_MODE_EN BIT(10)
#define DPHY_CMN_RX_BANDGAP_TIMER_MASK GENMASK(8, 1)
#define DPHY_CMN_SSM_EN BIT(0)
#define DPHY_CMN_RX_BANDGAP_TIMER 0x14
#define DPHY_BAND_CFG DPHY_PCS(0x0)
#define DPHY_BAND_CFG_RIGHT_BAND GENMASK(9, 5)
#define DPHY_BAND_CFG_LEFT_BAND GENMASK(4, 0)
#define DPHY_POWER_ISLAND_EN_DATA DPHY_PCS(0x8)
#define DPHY_POWER_ISLAND_EN_DATA_VAL 0xaaaaaaaa
#define DPHY_POWER_ISLAND_EN_CLK DPHY_PCS(0xc)
#define DPHY_POWER_ISLAND_EN_CLK_VAL 0xaa
#define DPHY_ISO_CL_CTRL_L DPHY_ISO(0x10)
#define DPHY_ISO_DL_CTRL_L0 DPHY_ISO(0x14)
#define DPHY_ISO_DL_CTRL_L1 DPHY_ISO(0x20)
#define DPHY_ISO_DL_CTRL_L2 DPHY_ISO(0x30)
#define DPHY_ISO_DL_CTRL_L3 DPHY_ISO(0x3c)
#define DPHY_ISO_LANE_READY_BIT 0
#define DPHY_ISO_LANE_READY_TIMEOUT_MS 100UL
#define DPHY_LANES_MIN 1
#define DPHY_LANES_MAX 4
struct cdns_dphy_rx {
void __iomem *regs;
struct device *dev;
struct phy *phy;
};
struct cdns_dphy_rx_band {
/* Rates are in Mbps. */
unsigned int min_rate;
unsigned int max_rate;
};
/* Order of bands is important since the index is the band number. */
static const struct cdns_dphy_rx_band bands[] = {
{ 80, 100 }, { 100, 120 }, { 120, 160 }, { 160, 200 }, { 200, 240 },
{ 240, 280 }, { 280, 320 }, { 320, 360 }, { 360, 400 }, { 400, 480 },
{ 480, 560 }, { 560, 640 }, { 640, 720 }, { 720, 800 }, { 800, 880 },
{ 880, 1040 }, { 1040, 1200 }, { 1200, 1350 }, { 1350, 1500 },
{ 1500, 1750 }, { 1750, 2000 }, { 2000, 2250 }, { 2250, 2500 }
};
static int cdns_dphy_rx_power_on(struct phy *phy)
{
struct cdns_dphy_rx *dphy = phy_get_drvdata(phy);
/* Start RX state machine. */
writel(DPHY_CMN_SSM_EN | DPHY_CMN_RX_MODE_EN |
FIELD_PREP(DPHY_CMN_RX_BANDGAP_TIMER_MASK,
DPHY_CMN_RX_BANDGAP_TIMER),
dphy->regs + DPHY_CMN_SSM);
return 0;
}
static int cdns_dphy_rx_power_off(struct phy *phy)
{
struct cdns_dphy_rx *dphy = phy_get_drvdata(phy);
writel(0, dphy->regs + DPHY_CMN_SSM);
return 0;
}
static int cdns_dphy_rx_get_band_ctrl(unsigned long hs_clk_rate)
{
unsigned int rate, i;
rate = hs_clk_rate / 1000000UL;
/* Since CSI-2 clock is DDR, the bit rate is twice the clock rate. */
rate *= 2;
if (rate < bands[0].min_rate)
return -EOPNOTSUPP;
for (i = 0; i < ARRAY_SIZE(bands); i++)
if (rate < bands[i].max_rate)
return i;
return -EOPNOTSUPP;
}
static inline int cdns_dphy_rx_wait_for_bit(void __iomem *addr,
unsigned int bit)
{
u32 val;
return readl_relaxed_poll_timeout(addr, val, val & BIT(bit), 10,
DPHY_ISO_LANE_READY_TIMEOUT_MS * 1000);
}
static int cdns_dphy_rx_wait_lane_ready(struct cdns_dphy_rx *dphy,
unsigned int lanes)
{
static const u32 data_lane_ctrl[] = {DPHY_ISO_DL_CTRL_L0,
DPHY_ISO_DL_CTRL_L1,
DPHY_ISO_DL_CTRL_L2,
DPHY_ISO_DL_CTRL_L3};
void __iomem *reg = dphy->regs;
unsigned int i;
int ret;
/* Clock lane */
ret = cdns_dphy_rx_wait_for_bit(reg + DPHY_ISO_CL_CTRL_L,
DPHY_ISO_LANE_READY_BIT);
if (ret)
return ret;
for (i = 0; i < lanes; i++) {
ret = cdns_dphy_rx_wait_for_bit(reg + data_lane_ctrl[i],
DPHY_ISO_LANE_READY_BIT);
if (ret)
return ret;
}
return 0;
}
static int cdns_dphy_rx_configure(struct phy *phy,
union phy_configure_opts *opts)
{
struct cdns_dphy_rx *dphy = phy_get_drvdata(phy);
unsigned int reg, lanes = opts->mipi_dphy.lanes;
int band_ctrl, ret;
/* Data lanes. Minimum one lane is mandatory. */
if (lanes < DPHY_LANES_MIN || lanes > DPHY_LANES_MAX)
return -EINVAL;
band_ctrl = cdns_dphy_rx_get_band_ctrl(opts->mipi_dphy.hs_clk_rate);
if (band_ctrl < 0)
return band_ctrl;
reg = FIELD_PREP(DPHY_BAND_CFG_LEFT_BAND, band_ctrl) |
FIELD_PREP(DPHY_BAND_CFG_RIGHT_BAND, band_ctrl);
writel(reg, dphy->regs + DPHY_BAND_CFG);
/*
* Set the required power island phase 2 time. This is mandated by DPHY
* specs.
*/
reg = DPHY_POWER_ISLAND_EN_DATA_VAL;
writel(reg, dphy->regs + DPHY_POWER_ISLAND_EN_DATA);
reg = DPHY_POWER_ISLAND_EN_CLK_VAL;
writel(reg, dphy->regs + DPHY_POWER_ISLAND_EN_CLK);
ret = cdns_dphy_rx_wait_lane_ready(dphy, lanes);
if (ret) {
dev_err(dphy->dev, "DPHY wait for lane ready timeout\n");
return ret;
}
return 0;
}
static int cdns_dphy_rx_validate(struct phy *phy, enum phy_mode mode,
int submode, union phy_configure_opts *opts)
{
int ret;
if (mode != PHY_MODE_MIPI_DPHY)
return -EINVAL;
ret = cdns_dphy_rx_get_band_ctrl(opts->mipi_dphy.hs_clk_rate);
if (ret < 0)
return ret;
return phy_mipi_dphy_config_validate(&opts->mipi_dphy);
}
static const struct phy_ops cdns_dphy_rx_ops = {
.power_on = cdns_dphy_rx_power_on,
.power_off = cdns_dphy_rx_power_off,
.configure = cdns_dphy_rx_configure,
.validate = cdns_dphy_rx_validate,
};
static int cdns_dphy_rx_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct phy_provider *provider;
struct cdns_dphy_rx *dphy;
dphy = devm_kzalloc(dev, sizeof(*dphy), GFP_KERNEL);
if (!dphy)
return -ENOMEM;
dev_set_drvdata(dev, dphy);
dphy->dev = dev;
dphy->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(dphy->regs))
return PTR_ERR(dphy->regs);
dphy->phy = devm_phy_create(dev, NULL, &cdns_dphy_rx_ops);
if (IS_ERR(dphy->phy)) {
dev_err(dev, "Failed to create PHY: %ld\n", PTR_ERR(dphy->phy));
return PTR_ERR(dphy->phy);
}
phy_set_drvdata(dphy->phy, dphy);
provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
if (IS_ERR(provider)) {
dev_err(dev, "Failed to register PHY provider: %ld\n",
PTR_ERR(provider));
return PTR_ERR(provider);
}
return 0;
}
static const struct of_device_id cdns_dphy_rx_of_match[] = {
{ .compatible = "cdns,dphy-rx" },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, cdns_dphy_rx_of_match);
static struct platform_driver cdns_dphy_rx_platform_driver = {
.probe = cdns_dphy_rx_probe,
.driver = {
.name = "cdns-mipi-dphy-rx",
.of_match_table = cdns_dphy_rx_of_match,
},
};
module_platform_driver(cdns_dphy_rx_platform_driver);
MODULE_AUTHOR("Pratyush Yadav <p.yadav@ti.com>");
MODULE_DESCRIPTION("Cadence D-PHY Rx Driver");
MODULE_LICENSE("GPL");