[PATCH v2 04/18] phy: cdns-dphy: Add Rx support
Tomi Valkeinen
tomi.valkeinen at ideasonboard.com
Thu May 27 23:09:25 PDT 2021
On 26/05/2021 18:22, Pratyush Yadav wrote:
> The Cadence DPHY can be used to receive image data over the CSI-2
> protocol. Add support for Rx mode. The programming sequence differs from
> the Tx mode so it is added as a separate set of hooks to isolate the two
> paths.
>
> The PHY is in Tx mode by default and it needs to be set in Rx mode by
> setting the submode to PHY_MIPI_DPHY_SUBMODE_RX in the set_mode()
> callback.
>
> Signed-off-by: Pratyush Yadav <p.yadav at ti.com>
> ---
>
> (no changes since v1)
>
> drivers/phy/cadence/cdns-dphy.c | 237 ++++++++++++++++++++++++++++++++
> 1 file changed, 237 insertions(+)
>
> diff --git a/drivers/phy/cadence/cdns-dphy.c b/drivers/phy/cadence/cdns-dphy.c
> index 7d5f7b333893..7bbca679e2bb 100644
> --- a/drivers/phy/cadence/cdns-dphy.c
> +++ b/drivers/phy/cadence/cdns-dphy.c
> @@ -1,11 +1,14 @@
> // SPDX-License-Identifier: GPL-2.0+
> /*
> * Copyright: 2017-2018 Cadence Design Systems, Inc.
> + * Copyright (C) 2021 Texas Instruments Incorporated - https://www.ti.com/
> */
>
> #include <linux/bitops.h>
> +#include <linux/bitfield.h>
> #include <linux/clk.h>
> #include <linux/io.h>
> +#include <linux/iopoll.h>
> #include <linux/module.h>
> #include <linux/of_address.h>
> #include <linux/of_device.h>
> @@ -25,10 +28,14 @@
> #define DPHY_PMA_RCLK(reg) (0x600 + (reg))
> #define DPHY_PMA_RDATA(lane, reg) (0x700 + ((lane) * 0x100) + (reg))
> #define DPHY_PCS(reg) (0xb00 + (reg))
> +#define DPHY_ISO(reg) (0xc00 + (reg))
>
> #define DPHY_CMN_SSM DPHY_PMA_CMN(0x20)
> #define DPHY_CMN_SSM_EN BIT(0)
> +#define DPHY_CMN_RX_BANDGAP_TIMER_MASK GENMASK(8, 1)
> #define DPHY_CMN_TX_MODE_EN BIT(9)
> +#define DPHY_CMN_RX_MODE_EN BIT(10)
> +#define DPHY_CMN_RX_BANDGAP_TIMER 0x14
>
> #define DPHY_CMN_PWM DPHY_PMA_CMN(0x40)
> #define DPHY_CMN_PWM_DIV(x) ((x) << 20)
> @@ -45,10 +52,27 @@
> #define DPHY_CMN_OPDIV_FROM_REG BIT(6)
> #define DPHY_CMN_OPDIV(x) ((x) << 7)
>
> +#define DPHY_BAND_CFG DPHY_PCS(0x0)
> +#define DPHY_BAND_CFG_LEFT_BAND GENMASK(4, 0)
> +#define DPHY_BAND_CFG_RIGHT_BAND GENMASK(9, 5)
> +
> #define DPHY_PSM_CFG DPHY_PCS(0x4)
> #define DPHY_PSM_CFG_FROM_REG BIT(0)
> #define DPHY_PSM_CLK_DIV(x) ((x) << 1)
>
> +#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 DSI_HBP_FRAME_OVERHEAD 12
> #define DSI_HSA_FRAME_OVERHEAD 14
> #define DSI_HFP_FRAME_OVERHEAD 6
> @@ -57,6 +81,9 @@
> #define DSI_NULL_FRAME_OVERHEAD 6
> #define DSI_EOT_PKT_SIZE 4
>
> +#define DPHY_LANES_MIN 1
> +#define DPHY_LANES_MAX 4
> +
> struct cdns_dphy_cfg {
> u8 pll_ipdiv;
> u8 pll_opdiv;
> @@ -312,6 +339,214 @@ static const struct cdns_dphy_ops tx_ref_dphy_ops = {
> .set_psm_div = cdns_dphy_ref_set_psm_div,
> };
>
> +static int cdns_dphy_rx_power_on(struct cdns_dphy *dphy)
> +{
> + /* 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 cdns_dphy *dphy)
> +{
> + 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 = hs_clk_rate / 1000000UL;
> +
> + if (rate < 80 || rate >= 2500)
> + return -EOPNOTSUPP;
> +
> + if (rate >= 80 && rate < 100)
> + return 0;
> +
> + if (rate >= 100 && rate < 120)
> + return 1;
> +
> + if (rate >= 120 && rate < 160)
> + return 2;
> +
> + if (rate >= 160 && rate < 200)
> + return 3;
> +
> + if (rate >= 200 && rate < 240)
> + return 4;
> +
> + if (rate >= 240 && rate < 280)
> + return 5;
> +
> + if (rate >= 280 && rate < 320)
> + return 6;
> +
> + if (rate >= 320 && rate < 360)
> + return 7;
> +
> + if (rate >= 360 && rate < 400)
> + return 8;
> +
> + if (rate >= 400 && rate < 480)
> + return 9;
> +
> + if (rate >= 480 && rate < 560)
> + return 10;
> +
> + if (rate >= 560 && rate < 640)
> + return 11;
> +
> + if (rate >= 640 && rate < 720)
> + return 12;
> +
> + if (rate >= 720 && rate < 800)
> + return 13;
> +
> + if (rate >= 800 && rate < 880)
> + return 14;
> +
> + if (rate >= 880 && rate < 1040)
> + return 15;
> +
> + if (rate >= 1040 && rate < 1200)
> + return 16;
> +
> + if (rate >= 1200 && rate < 1350)
> + return 17;
> +
> + if (rate >= 1350 && rate < 1500)
> + return 18;
> +
> + if (rate >= 1500 && rate < 1750)
> + return 19;
> +
> + if (rate >= 1750 && rate < 2000)
> + return 20;
> +
> + if (rate >= 2000 && rate < 2250)
> + return 21;
> +
> + if (rate >= 2250 && rate < 2500)
> + return 22;
> +
All the above could be handled with a simple table and a for loop.
> + /* Unreachable. */
> + WARN(1, "Reached unreachable code.");
> + return -EINVAL;
> +}
> +
> +static 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 *dphy, int lanes)
> +{
> + void __iomem *reg = dphy->regs;
> + int ret;
> +
> + if (lanes < DPHY_LANES_MIN || lanes > DPHY_LANES_MAX)
> + return -EINVAL;
> +
> + /* Clock lane */
> + ret = cdns_dphy_rx_wait_for_bit(reg + DPHY_ISO_CL_CTRL_L,
> + DPHY_ISO_LANE_READY_BIT);
> + if (ret)
> + return ret;
> +
> + /* Data lanes. Minimum one lane is mandatory. */
> + ret = cdns_dphy_rx_wait_for_bit(reg + DPHY_ISO_DL_CTRL_L0,
> + DPHY_ISO_LANE_READY_BIT);
> + if (ret)
> + return ret;
> +
> + if (lanes < 2)
> + return 0;
> +
> + ret = cdns_dphy_rx_wait_for_bit(reg + DPHY_ISO_DL_CTRL_L1,
> + DPHY_ISO_LANE_READY_BIT);
> + if (ret)
> + return ret;
> +
> + if (lanes < 3)
> + return 0;
> +
> + ret = cdns_dphy_rx_wait_for_bit(reg + DPHY_ISO_DL_CTRL_L2,
> + DPHY_ISO_LANE_READY_BIT);
> + if (ret)
> + return ret;
> +
> + if (lanes < 4)
> + return 0;
> +
> + ret = cdns_dphy_rx_wait_for_bit(reg + DPHY_ISO_DL_CTRL_L3,
> + DPHY_ISO_LANE_READY_BIT);
> + if (ret)
> + return ret;
> +
This, too, could be handled with an array (for the regs) and a for loop.
Tomi
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