On 18/01/2026 13:05, Kieran Bingham wrote:
Quoting Bryan O'Donoghue (2026-01-17 21:38:17)On 17/01/2026 15:36, David Heidelberg via B4 Relay wrote:From: David Heidelberg <[email protected]>So far, only D-PHY mode was supported, which uses even bits when enabling or masking lanes. For C-PHY configuration, the hardware instead requires using the odd bits. Since there can be unrecognized configuration allow returning failure. Signed-off-by: David Heidelberg <[email protected]> --- .../platform/qcom/camss/camss-csiphy-2ph-1-0.c | 8 ++-- .../platform/qcom/camss/camss-csiphy-3ph-1-0.c | 49 +++++++++++++++++----- drivers/media/platform/qcom/camss/camss-csiphy.c | 4 +- drivers/media/platform/qcom/camss/camss-csiphy.h | 6 +-- 4 files changed, 47 insertions(+), 20 deletions(-) diff --git a/drivers/media/platform/qcom/camss/camss-csiphy-2ph-1-0.c b/drivers/media/platform/qcom/camss/camss-csiphy-2ph-1-0.c index 9d67e7fa6366a..bb4b91f69616b 100644 --- a/drivers/media/platform/qcom/camss/camss-csiphy-2ph-1-0.c +++ b/drivers/media/platform/qcom/camss/camss-csiphy-2ph-1-0.c @@ -94,9 +94,9 @@ static u8 csiphy_settle_cnt_calc(s64 link_freq, u32 timer_clk_rate) return settle_cnt; }-static void csiphy_lanes_enable(struct csiphy_device *csiphy,- struct csiphy_config *cfg, - s64 link_freq, u8 lane_mask) +static int csiphy_lanes_enable(struct csiphy_device *csiphy, + struct csiphy_config *cfg, + s64 link_freq, u8 lane_mask) { struct csiphy_lanes_cfg *c = &cfg->csi2->lane_cfg; u8 settle_cnt; @@ -132,6 +132,8 @@ static void csiphy_lanes_enable(struct csiphy_device *csiphy, writel_relaxed(0x3f, csiphy->base + CAMSS_CSI_PHY_INTERRUPT_CLEARn(l)); } + + return 0; }static void csiphy_lanes_disable(struct csiphy_device *csiphy,diff --git a/drivers/media/platform/qcom/camss/camss-csiphy-3ph-1-0.c b/drivers/media/platform/qcom/camss/camss-csiphy-3ph-1-0.c index 4154832745525..f3a8625511e1e 100644 --- a/drivers/media/platform/qcom/camss/camss-csiphy-3ph-1-0.c +++ b/drivers/media/platform/qcom/camss/camss-csiphy-3ph-1-0.c @@ -14,6 +14,7 @@ #include <linux/delay.h> #include <linux/interrupt.h> #include <linux/io.h> +#include <linux/media-bus-format.h>#define CSIPHY_3PH_LNn_CFG1(n) (0x000 + 0x100 * (n))#define CSIPHY_3PH_LNn_CFG1_SWI_REC_DLY_PRG (BIT(7) | BIT(6)) @@ -993,13 +994,22 @@ static void csiphy_gen2_config_lanes(struct csiphy_device *csiphy,static u8 csiphy_get_lane_mask(struct csiphy_lanes_cfg *lane_cfg){ - u8 lane_mask; - int i; + u8 lane_mask = 0;- lane_mask = CSIPHY_3PH_CMN_CSI_COMMON_CTRL5_CLK_ENABLE;+ switch (lane_cfg->phy_cfg) { + case V4L2_MBUS_CSI2_CPHY: + for (int i = 0; i < lane_cfg->num_data; i++) + lane_mask |= (1 << lane_cfg->data[i].pos) + 1;1 << anything == BIT(anything) I've always disliked the look of this code and now it occurs to me why. This code is analogous to: lane_mask |= BIT(lane_cfg->data[i].pos) + 1);I see that addition to a bit mask and get a little bit scared. This gives: pos mask 0 0b00000010 (note 0 bit is zero here but 1 on all others) 1 0b00000011 2 0b00000101 3 0b00001001 4 0b00010001 Is that expected? Can data[i].pos ever be position 0 ?? I assume this starts at position 1 - and the +1 here is to always set the zeroth bit ? Perhapse this might be precise to convey that in such a case? lane_mask |= BIT(pos) | 1; I guess it depends on what this is really being used for which I don't have in my context.
I currently don't see clear way forward, maybe someone from qcom could give a hint how to continue?
Thanks David
-- Kieranbut BIT() is less janky and more upstreamy. janky/upstreamy - this is the on-point technical argument y'all came here for :)+ break; + case V4L2_MBUS_CSI2_DPHY: + lane_mask = CSIPHY_3PH_CMN_CSI_COMMON_CTRL5_CLK_ENABLE;- for (i = 0; i < lane_cfg->num_data; i++)- lane_mask |= 1 << lane_cfg->data[i].pos; + for (int i = 0; i < lane_cfg->num_data; i++) + lane_mask |= 1 << lane_cfg->data[i].pos; + break; + default: + break; + }return lane_mask;} @@ -1027,10 +1037,11 @@ static bool csiphy_is_gen2(u32 version) return ret; }-static void csiphy_lanes_enable(struct csiphy_device *csiphy,- struct csiphy_config *cfg, - s64 link_freq, u8 lane_mask) +static int csiphy_lanes_enable(struct csiphy_device *csiphy, + struct csiphy_config *cfg, + s64 link_freq, u8 lane_mask) { + struct device *dev = csiphy->camss->dev; struct csiphy_lanes_cfg *c = &cfg->csi2->lane_cfg; struct csiphy_device_regs *regs = csiphy->regs; u8 settle_cnt; @@ -1039,9 +1050,23 @@ static void csiphy_lanes_enable(struct csiphy_device *csiphy,settle_cnt = csiphy_settle_cnt_calc(link_freq, csiphy->timer_clk_rate); - val = CSIPHY_3PH_CMN_CSI_COMMON_CTRL5_CLK_ENABLE;- for (i = 0; i < c->num_data; i++) - val |= BIT(c->data[i].pos * 2); + val = 0; + + switch (c->phy_cfg) { + case V4L2_MBUS_CSI2_CPHY: + for (i = 0; i < c->num_data; i++) + val |= BIT((c->data[i].pos * 2) + 1); + break; + case V4L2_MBUS_CSI2_DPHY: + val = CSIPHY_3PH_CMN_CSI_COMMON_CTRL5_CLK_ENABLE; + + for (i = 0; i < c->num_data; i++) + val |= BIT(c->data[i].pos * 2); + break; + default: + dev_err(dev, "Unsupported bus type %d\n", c->phy_cfg); + return -EINVAL; + }writel_relaxed(val, csiphy->base +CSIPHY_3PH_CMN_CSI_COMMON_CTRLn(regs->offset, 5)); @@ -1068,6 +1093,8 @@ static void csiphy_lanes_enable(struct csiphy_device *csiphy, writel_relaxed(0, csiphy->base + CSIPHY_3PH_CMN_CSI_COMMON_CTRLn(regs->offset, i)); } + + return 0; }static void csiphy_lanes_disable(struct csiphy_device *csiphy,diff --git a/drivers/media/platform/qcom/camss/camss-csiphy.c b/drivers/media/platform/qcom/camss/camss-csiphy.c index 62623393f4144..08dd238e52799 100644 --- a/drivers/media/platform/qcom/camss/camss-csiphy.c +++ b/drivers/media/platform/qcom/camss/camss-csiphy.c @@ -295,9 +295,7 @@ static int csiphy_stream_on(struct csiphy_device *csiphy) wmb(); }- csiphy->res->hw_ops->lanes_enable(csiphy, cfg, link_freq, lane_mask);- - return 0; + return csiphy->res->hw_ops->lanes_enable(csiphy, cfg, link_freq, lane_mask);ick. More high brow stuff from bod here but, more seriously this is three levels of indirection deep and the statement keeps getting longer. Could you get a pointer to hw_ops() to reduce this down a bit.}/*diff --git a/drivers/media/platform/qcom/camss/camss-csiphy.h b/drivers/media/platform/qcom/camss/camss-csiphy.h index d198171700e73..21cf2ce931c1d 100644 --- a/drivers/media/platform/qcom/camss/camss-csiphy.h +++ b/drivers/media/platform/qcom/camss/camss-csiphy.h @@ -73,9 +73,9 @@ struct csiphy_hw_ops { void (*hw_version_read)(struct csiphy_device *csiphy, struct device *dev); void (*reset)(struct csiphy_device *csiphy); - void (*lanes_enable)(struct csiphy_device *csiphy, - struct csiphy_config *cfg, - s64 link_freq, u8 lane_mask); + int (*lanes_enable)(struct csiphy_device *csiphy, + struct csiphy_config *cfg, + s64 link_freq, u8 lane_mask); void (*lanes_disable)(struct csiphy_device *csiphy, struct csiphy_config *cfg); irqreturn_t (*isr)(int irq, void *dev);With those tweaks. Reviewed-by: Bryan O'Donoghue <[email protected]> --- bod
-- David Heidelberg
