Hi Maxime, On Tue, Nov 06, 2018 at 03:54:20PM +0100, Maxime Ripard wrote: > Cadence has designed a D-PHY that can be used by the, currently in tree, > DSI bridge (DRM), CSI Transceiver and CSI Receiver (v4l2) drivers. > > Only the DSI driver has an ad-hoc driver for that phy at the moment, while > the v4l2 drivers are completely missing any phy support. In order to make > that phy support available to all these drivers, without having to > duplicate that code three times, let's create a generic phy framework > driver. > > Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxx> > --- > Documentation/devicetree/bindings/display/bridge/cdns,dsi.txt | 21 +- > Documentation/devicetree/bindings/phy/cdns,dphy.txt | 20 +- Coould you split out the DT binding changes into a separate patch? > drivers/phy/cadence/Kconfig | 13 +- > drivers/phy/cadence/Makefile | 1 +- > drivers/phy/cadence/cdns-dphy.c | 459 +++++++- > 5 files changed, 492 insertions(+), 22 deletions(-) > create mode 100644 Documentation/devicetree/bindings/phy/cdns,dphy.txt > create mode 100644 drivers/phy/cadence/cdns-dphy.c > > diff --git a/Documentation/devicetree/bindings/display/bridge/cdns,dsi.txt b/Documentation/devicetree/bindings/display/bridge/cdns,dsi.txt > index f5725bb6c61c..525a4bfd8634 100644 > --- a/Documentation/devicetree/bindings/display/bridge/cdns,dsi.txt > +++ b/Documentation/devicetree/bindings/display/bridge/cdns,dsi.txt > @@ -31,28 +31,7 @@ Required subnodes: > - one subnode per DSI device connected on the DSI bus. Each DSI device should > contain a reg property encoding its virtual channel. > > -Cadence DPHY > -============ > - > -Cadence DPHY block. > - > -Required properties: > -- compatible: should be set to "cdns,dphy". > -- reg: physical base address and length of the DPHY registers. > -- clocks: DPHY reference clocks. > -- clock-names: must contain "psm" and "pll_ref". > -- #phy-cells: must be set to 0. > - > - > Example: > - dphy0: dphy@fd0e0000{ > - compatible = "cdns,dphy"; > - reg = <0x0 0xfd0e0000 0x0 0x1000>; > - clocks = <&psm_clk>, <&pll_ref_clk>; > - clock-names = "psm", "pll_ref"; > - #phy-cells = <0>; > - }; > - > dsi0: dsi@fd0c0000 { > compatible = "cdns,dsi"; > reg = <0x0 0xfd0c0000 0x0 0x1000>; > diff --git a/Documentation/devicetree/bindings/phy/cdns,dphy.txt b/Documentation/devicetree/bindings/phy/cdns,dphy.txt > new file mode 100644 > index 000000000000..1095bc4e72d9 > --- /dev/null > +++ b/Documentation/devicetree/bindings/phy/cdns,dphy.txt > @@ -0,0 +1,20 @@ > +Cadence DPHY > +============ > + > +Cadence DPHY block. > + > +Required properties: > +- compatible: should be set to "cdns,dphy". > +- reg: physical base address and length of the DPHY registers. > +- clocks: DPHY reference clocks. > +- clock-names: must contain "psm" and "pll_ref". > +- #phy-cells: must be set to 0. > + > +Example: > + dphy0: dphy@fd0e0000{ > + compatible = "cdns,dphy"; > + reg = <0x0 0xfd0e0000 0x0 0x1000>; > + clocks = <&psm_clk>, <&pll_ref_clk>; > + clock-names = "psm", "pll_ref"; > + #phy-cells = <0>; > + }; > diff --git a/drivers/phy/cadence/Kconfig b/drivers/phy/cadence/Kconfig > index 57fff7de4031..240effa81046 100644 > --- a/drivers/phy/cadence/Kconfig > +++ b/drivers/phy/cadence/Kconfig > @@ -1,6 +1,7 @@ > # > -# Phy driver for Cadence MHDP DisplayPort controller > +# Phy drivers for Cadence IPs > # > + > config PHY_CADENCE_DP > tristate "Cadence MHDP DisplayPort PHY driver" > depends on OF > @@ -8,3 +9,13 @@ config PHY_CADENCE_DP > select GENERIC_PHY > help > Support for Cadence MHDP DisplayPort PHY. > + > +config PHY_CADENCE_DPHY > + tristate "Cadence D-PHY Support" > + depends on HAS_IOMEM && OF > + select GENERIC_PHY > + select GENERIC_PHY_MIPI_DPHY > + help > + Choose this option if you have a Cadence D-PHY in your > + system. If M is selected, the module will be called > + cdns-csi. > diff --git a/drivers/phy/cadence/Makefile b/drivers/phy/cadence/Makefile > index e5b0a11cf28a..64cb9ea66ceb 100644 > --- a/drivers/phy/cadence/Makefile > +++ b/drivers/phy/cadence/Makefile > @@ -1 +1,2 @@ > obj-$(CONFIG_PHY_CADENCE_DP) += phy-cadence-dp.o > +obj-$(CONFIG_PHY_CADENCE_DPHY) += cdns-dphy.o > diff --git a/drivers/phy/cadence/cdns-dphy.c b/drivers/phy/cadence/cdns-dphy.c > new file mode 100644 > index 000000000000..a398b401e5d3 > --- /dev/null > +++ b/drivers/phy/cadence/cdns-dphy.c > @@ -0,0 +1,459 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +/* > + * Copyright: 2017-2018 Cadence Design Systems, Inc. > + */ > + > +#include <linux/bitops.h> > +#include <linux/clk.h> > +#include <linux/io.h> > +#include <linux/module.h> > +#include <linux/of_address.h> > +#include <linux/of_device.h> > +#include <linux/platform_device.h> > +#include <linux/reset.h> > + > +#include <linux/phy/phy.h> > +#include <linux/phy/phy-mipi-dphy.h> > + > +#define REG_WAKEUP_TIME_NS 800 > +#define DPHY_PLL_RATE_HZ 108000000 > + > +/* DPHY registers */ > +#define DPHY_PMA_CMN(reg) (reg) > +#define DPHY_PMA_LCLK(reg) (0x100 + (reg)) > +#define DPHY_PMA_LDATA(lane, reg) (0x200 + ((lane) * 0x100) + (reg)) > +#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_CMN_SSM DPHY_PMA_CMN(0x20) > +#define DPHY_CMN_SSM_EN BIT(0) > +#define DPHY_CMN_TX_MODE_EN BIT(9) > + > +#define DPHY_CMN_PWM DPHY_PMA_CMN(0x40) > +#define DPHY_CMN_PWM_DIV(x) ((x) << 20) > +#define DPHY_CMN_PWM_LOW(x) ((x) << 10) > +#define DPHY_CMN_PWM_HIGH(x) (x) > + > +#define DPHY_CMN_FBDIV DPHY_PMA_CMN(0x4c) > +#define DPHY_CMN_FBDIV_VAL(low, high) (((high) << 11) | ((low) << 22)) > +#define DPHY_CMN_FBDIV_FROM_REG (BIT(10) | BIT(21)) > + > +#define DPHY_CMN_OPIPDIV DPHY_PMA_CMN(0x50) > +#define DPHY_CMN_IPDIV_FROM_REG BIT(0) > +#define DPHY_CMN_IPDIV(x) ((x) << 1) > +#define DPHY_CMN_OPDIV_FROM_REG BIT(6) > +#define DPHY_CMN_OPDIV(x) ((x) << 7) > + > +#define DPHY_PSM_CFG DPHY_PCS(0x4) > +#define DPHY_PSM_CFG_FROM_REG BIT(0) > +#define DPHY_PSM_CLK_DIV(x) ((x) << 1) > + > +#define DSI_HBP_FRAME_OVERHEAD 12 > +#define DSI_HSA_FRAME_OVERHEAD 14 > +#define DSI_HFP_FRAME_OVERHEAD 6 > +#define DSI_HSS_VSS_VSE_FRAME_OVERHEAD 4 > +#define DSI_BLANKING_FRAME_OVERHEAD 6 > +#define DSI_NULL_FRAME_OVERHEAD 6 > +#define DSI_EOT_PKT_SIZE 4 > + > +struct cdns_dphy_cfg { > + u8 pll_ipdiv; > + u8 pll_opdiv; > + u16 pll_fbdiv; > + unsigned int nlanes; > +}; > + > +enum cdns_dphy_clk_lane_cfg { > + DPHY_CLK_CFG_LEFT_DRIVES_ALL = 0, > + DPHY_CLK_CFG_LEFT_DRIVES_RIGHT = 1, > + DPHY_CLK_CFG_LEFT_DRIVES_LEFT = 2, > + DPHY_CLK_CFG_RIGHT_DRIVES_ALL = 3, > +}; > + > +struct cdns_dphy; > +struct cdns_dphy_ops { > + int (*probe)(struct cdns_dphy *dphy); > + void (*remove)(struct cdns_dphy *dphy); > + void (*set_psm_div)(struct cdns_dphy *dphy, u8 div); > + void (*set_clk_lane_cfg)(struct cdns_dphy *dphy, > + enum cdns_dphy_clk_lane_cfg cfg); > + void (*set_pll_cfg)(struct cdns_dphy *dphy, > + const struct cdns_dphy_cfg *cfg); > + unsigned long (*get_wakeup_time_ns)(struct cdns_dphy *dphy); > +}; > + > +struct cdns_dphy { > + struct cdns_dphy_cfg cfg; > + void __iomem *regs; > + struct clk *psm_clk; > + struct clk *pll_ref_clk; > + const struct cdns_dphy_ops *ops; > + struct phy *phy; > +}; > + > +static int cdns_dsi_get_dphy_pll_cfg(struct cdns_dphy *dphy, > + struct cdns_dphy_cfg *cfg, > + struct phy_configure_opts_mipi_dphy *opts, > + unsigned int *dsi_hfp_ext) > +{ > + u64 dlane_bps, dlane_bps_max, fbdiv, fbdiv_max, adj_dsi_htotal; > + unsigned long pll_ref_hz = clk_get_rate(dphy->pll_ref_clk); > + > + memset(cfg, 0, sizeof(*cfg)); > + > + if (pll_ref_hz < 9600000 || pll_ref_hz >= 150000000) > + return -EINVAL; > + else if (pll_ref_hz < 19200000) > + cfg->pll_ipdiv = 1; > + else if (pll_ref_hz < 38400000) > + cfg->pll_ipdiv = 2; > + else if (pll_ref_hz < 76800000) > + cfg->pll_ipdiv = 4; > + else > + cfg->pll_ipdiv = 8; > + > + dlane_bps = opts->hs_clk_rate; > + > + if (dlane_bps > 2500000000UL || dlane_bps < 160000000UL) > + return -EINVAL; > + else if (dlane_bps >= 1250000000) > + cfg->pll_opdiv = 1; > + else if (dlane_bps >= 630000000) > + cfg->pll_opdiv = 2; > + else if (dlane_bps >= 320000000) > + cfg->pll_opdiv = 4; > + else if (dlane_bps >= 160000000) > + cfg->pll_opdiv = 8; > + > + /* > + * Allow a deviation of 0.2% on the per-lane data rate to try to > + * recover a potential mismatch between DPI and PPI clks. > + */ > + dlane_bps_max = dlane_bps + DIV_ROUND_DOWN_ULL(dlane_bps, 500); > + fbdiv_max = DIV_ROUND_DOWN_ULL(dlane_bps_max * 2 * > + cfg->pll_opdiv * cfg->pll_ipdiv, > + pll_ref_hz); > + fbdiv = DIV_ROUND_UP_ULL(dlane_bps * 2 * cfg->pll_opdiv * > + cfg->pll_ipdiv, > + pll_ref_hz); > + > + /* > + * Iterate over all acceptable fbdiv and try to find an adjusted DSI > + * htotal length providing an exact match. > + * > + * Note that we could do something even trickier by relying on the fact > + * that a new line is not necessarily aligned on a lane boundary, so, > + * by making adj_dsi_htotal non aligned on a dsi_lanes we can improve a > + * bit the precision. With this, the step would be > + * > + * pll_ref_hz / (2 * opdiv * ipdiv * nlanes) > + * > + * instead of > + * > + * pll_ref_hz / (2 * opdiv * ipdiv) > + * > + * The drawback of this approach is that we would need to make sure the > + * number or lines is a multiple of the realignment periodicity which is > + * a function of the number of lanes and the original misalignment. For > + * example, for NLANES = 4 and HTOTAL % NLANES = 3, it takes 4 lines > + * to realign on a lane: > + * LINE 0: expected number of bytes, starts emitting first byte of > + * LINE 1 on LANE 3 > + * LINE 1: expected number of bytes, starts emitting first 2 bytes of > + * LINE 2 on LANES 2 and 3 > + * LINE 2: expected number of bytes, starts emitting first 3 bytes of > + * of LINE 3 on LANES 1, 2 and 3 > + * LINE 3: one byte less, now things are realigned on LANE 0 for LINE 4 > + * > + * I figured this extra complexity was not worth the benefit, but if > + * someone really has unfixable mismatch, that would be something to > + * investigate. > + */ > + for (; fbdiv <= fbdiv_max; fbdiv++) { > + u32 rem; > + > + /* > + * Do the division in 2 steps to avoid an overflow on the > + * divider. > + */ > + rem = do_div(adj_dsi_htotal, opts->hs_clk_rate); Hmm. I don't see adj_dsi_htotal being set anywhere. I suppose that can't be intended. > + if (rem) > + continue; > + > + rem = do_div(adj_dsi_htotal, > + cfg->pll_opdiv * cfg->pll_ipdiv * 2 * 8); > + if (rem) > + continue; Is fbdiv supposed to be used in the formula somewhere? > + > + cfg->pll_fbdiv = fbdiv; > + break; > + } > + > + /* No match, let's just reject the display mode. */ > + if (!cfg->pll_fbdiv) > + return -EINVAL; > + > + return 0; > +} > + > +static int cdns_dphy_setup_psm(struct cdns_dphy *dphy) > +{ > + unsigned long psm_clk_hz = clk_get_rate(dphy->psm_clk); > + unsigned long psm_div; > + > + if (!psm_clk_hz || psm_clk_hz > 100000000) > + return -EINVAL; > + > + psm_div = DIV_ROUND_CLOSEST(psm_clk_hz, 1000000); > + if (dphy->ops->set_psm_div) > + dphy->ops->set_psm_div(dphy, psm_div); > + > + return 0; > +} > + > +static void cdns_dphy_set_clk_lane_cfg(struct cdns_dphy *dphy, > + enum cdns_dphy_clk_lane_cfg cfg) > +{ > + if (dphy->ops->set_clk_lane_cfg) > + dphy->ops->set_clk_lane_cfg(dphy, cfg); > +} > + > +static void cdns_dphy_set_pll_cfg(struct cdns_dphy *dphy, > + const struct cdns_dphy_cfg *cfg) > +{ > + if (dphy->ops->set_pll_cfg) > + dphy->ops->set_pll_cfg(dphy, cfg); > +} > + > +static unsigned long cdns_dphy_get_wakeup_time_ns(struct cdns_dphy *dphy) > +{ > + return dphy->ops->get_wakeup_time_ns(dphy); > +} > + > +static unsigned long cdns_dphy_ref_get_wakeup_time_ns(struct cdns_dphy *dphy) > +{ > + /* Default wakeup time is 800 ns (in a simulated environment). */ > + return 800; > +} > + > +static void cdns_dphy_ref_set_pll_cfg(struct cdns_dphy *dphy, > + const struct cdns_dphy_cfg *cfg) > +{ > + u32 fbdiv_low, fbdiv_high; > + > + fbdiv_low = (cfg->pll_fbdiv / 4) - 2; > + fbdiv_high = cfg->pll_fbdiv - fbdiv_low - 2; > + > + writel(DPHY_CMN_IPDIV_FROM_REG | DPHY_CMN_OPDIV_FROM_REG | > + DPHY_CMN_IPDIV(cfg->pll_ipdiv) | > + DPHY_CMN_OPDIV(cfg->pll_opdiv), > + dphy->regs + DPHY_CMN_OPIPDIV); > + writel(DPHY_CMN_FBDIV_FROM_REG | > + DPHY_CMN_FBDIV_VAL(fbdiv_low, fbdiv_high), > + dphy->regs + DPHY_CMN_FBDIV); > + writel(DPHY_CMN_PWM_HIGH(6) | DPHY_CMN_PWM_LOW(0x101) | > + DPHY_CMN_PWM_DIV(0x8), > + dphy->regs + DPHY_CMN_PWM); > +} > + > +static void cdns_dphy_ref_set_psm_div(struct cdns_dphy *dphy, u8 div) > +{ > + writel(DPHY_PSM_CFG_FROM_REG | DPHY_PSM_CLK_DIV(div), > + dphy->regs + DPHY_PSM_CFG); > +} > + > +/* > + * This is the reference implementation of DPHY hooks. Specific integration of > + * this IP may have to re-implement some of them depending on how they decided > + * to wire things in the SoC. > + */ > +static const struct cdns_dphy_ops ref_dphy_ops = { > + .get_wakeup_time_ns = cdns_dphy_ref_get_wakeup_time_ns, > + .set_pll_cfg = cdns_dphy_ref_set_pll_cfg, > + .set_psm_div = cdns_dphy_ref_set_psm_div, > +}; > + > +static int cdns_dphy_config_from_opts(struct phy *phy, > + struct phy_configure_opts_mipi_dphy *opts, > + struct cdns_dphy_cfg *cfg) > +{ > + struct cdns_dphy *dphy = phy_get_drvdata(phy); > + unsigned int dsi_hfp_ext = 0; > + int ret; > + > + ret = phy_mipi_dphy_config_validate(opts); > + if (ret) > + return ret; > + > + ret = cdns_dsi_get_dphy_pll_cfg(dphy, cfg, > + opts, &dsi_hfp_ext); > + if (ret) > + return ret; > + > + opts->wakeup = cdns_dphy_get_wakeup_time_ns(dphy); > + > + return 0; > +} > + > +static int cdns_dphy_init(struct phy *phy) > +{ > + struct cdns_dphy *dphy = phy_get_drvdata(phy); > + > + clk_prepare_enable(dphy->psm_clk); > + clk_prepare_enable(dphy->pll_ref_clk); > + > + return 0; > +} > + > +static int cdns_dphy_validate(struct phy *phy, enum phy_mode mode, > + union phy_configure_opts *opts) > +{ > + struct cdns_dphy_cfg cfg = { 0 }; > + > + if (mode != PHY_MODE_MIPI_DPHY) > + return -EINVAL; > + > + return cdns_dphy_config_from_opts(phy, &opts->mipi_dphy, &cfg); > +} > + > +static int cdns_dphy_configure(struct phy *phy, union phy_configure_opts *opts) > +{ > + struct cdns_dphy *dphy = phy_get_drvdata(phy); > + struct cdns_dphy_cfg cfg = { 0 }; > + int ret; > + > + ret = cdns_dphy_config_from_opts(phy, &opts->mipi_dphy, &cfg); > + if (ret) > + return ret; > + > + /* > + * Configure the internal PSM clk divider so that the DPHY has a > + * 1MHz clk (or something close). > + */ > + ret = cdns_dphy_setup_psm(dphy); > + if (ret) > + return ret; > + > + /* > + * Configure attach clk lanes to data lanes: the DPHY has 2 clk lanes > + * and 8 data lanes, each clk lane can be attache different set of > + * data lanes. The 2 groups are named 'left' and 'right', so here we > + * just say that we want the 'left' clk lane to drive the 'left' data > + * lanes. > + */ > + cdns_dphy_set_clk_lane_cfg(dphy, DPHY_CLK_CFG_LEFT_DRIVES_LEFT); > + > + /* > + * Configure the DPHY PLL that will be used to generate the TX byte > + * clk. > + */ > + cdns_dphy_set_pll_cfg(dphy, &cfg); > + > + return 0; > +} > + > +static int cdns_dphy_power_on(struct phy *phy) > +{ > + struct cdns_dphy *dphy = phy_get_drvdata(phy); > + > + /* Start TX state machine. */ > + writel(DPHY_CMN_SSM_EN | DPHY_CMN_TX_MODE_EN, dphy->regs + DPHY_CMN_SSM); > + > + return 0; > +} > + > +static int cdns_dphy_exit(struct phy *phy) > +{ > + struct cdns_dphy *dphy = phy_get_drvdata(phy); > + > + clk_disable_unprepare(dphy->pll_ref_clk); > + clk_disable_unprepare(dphy->psm_clk); Wouldn't this belong to power_off() (and enabling the clocks to power_on())? > + > + return 0; > +} > + > +static struct phy_ops cdns_dphy_ops = { const > + .configure = cdns_dphy_configure, > + .validate = cdns_dphy_validate, > + .power_on = cdns_dphy_power_on, How does it stop? Or does it? :-) > + .init = cdns_dphy_init, It'd be nice to maintain the order the same as in here (unless there are reasons to do otherwise, of course). > + .exit = cdns_dphy_exit, > +}; > + > +static int cdns_dphy_probe(struct platform_device *pdev) > +{ > + struct phy_provider *phy_provider; > + struct cdns_dphy *dphy; > + struct resource *res; > + int ret; > + > + dphy = devm_kzalloc(&pdev->dev, sizeof(*dphy), GFP_KERNEL); > + if (!dphy) > + return -ENOMEM; > + dev_set_drvdata(&pdev->dev, dphy); > + > + dphy->ops = of_device_get_match_data(&pdev->dev); > + if (!dphy->ops) > + return -EINVAL; > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + dphy->regs = devm_ioremap_resource(&pdev->dev, res); > + if (IS_ERR(dphy->regs)) > + return PTR_ERR(dphy->regs); > + > + dphy->psm_clk = devm_clk_get(&pdev->dev, "psm"); > + if (IS_ERR(dphy->psm_clk)) > + return PTR_ERR(dphy->psm_clk); > + > + dphy->pll_ref_clk = devm_clk_get(&pdev->dev, "pll_ref"); > + if (IS_ERR(dphy->pll_ref_clk)) > + return PTR_ERR(dphy->pll_ref_clk); > + > + if (dphy->ops->probe) { You could declare ret here. Entirely up to you. > + ret = dphy->ops->probe(dphy); > + if (ret) > + return ret; > + } > + > + dphy->phy = devm_phy_create(&pdev->dev, NULL, &cdns_dphy_ops); > + if (IS_ERR(dphy->phy)) { > + dev_err(&pdev->dev, "failed to create PHY\n"); > + return PTR_ERR(dphy->phy); Would it be appropriate to call the remove callback here? > + } > + > + phy_set_drvdata(dphy->phy, dphy); > + phy_provider = devm_of_phy_provider_register(&pdev->dev, of_phy_simple_xlate); > + > + return PTR_ERR_OR_ZERO(phy_provider); > +} > + > +static int cdns_dphy_remove(struct platform_device *pdev) > +{ > + struct cdns_dphy *dphy = dev_get_drvdata(&pdev->dev); > + > + if (dphy->ops->remove) > + dphy->ops->remove(dphy); > + > + return 0; > +} > + > +static const struct of_device_id cdns_dphy_of_match[] = { > + { .compatible = "cdns,dphy", .data = &ref_dphy_ops }, > + { /* sentinel */ }, > +}; > +MODULE_DEVICE_TABLE(of, cdns_dphy_of_match); > + > +static struct platform_driver cdns_dphy_platform_driver = { > + .probe = cdns_dphy_probe, > + .remove = cdns_dphy_remove, > + .driver = { > + .name = "cdns-mipi-dphy", > + .of_match_table = cdns_dphy_of_match, > + }, > +}; > +module_platform_driver(cdns_dphy_platform_driver); > + > +MODULE_AUTHOR("Maxime Ripard <maxime.ripard@bootlin>"); bootlin.com ? > +MODULE_DESCRIPTION("Cadence MIPI D-PHY Driver"); > +MODULE_LICENSE("GPL"); -- Regards, Sakari Ailus e-mail: sakari.ailus@xxxxxx