On 22/03/2024 11:41, Dmitry Baryshkov wrote:
On Fri, 22 Mar 2024 at 11:43, Neil Armstrong <neil.armstrong@xxxxxxxxxx> wrote:
The PCIe Gen4x2 PHY found in the SM8[456]50 SoCs have a second clock,
add the code to register it for PHYs configs that sets a aux_clock_rate.
In order to get the right clock, add qmp_pcie_clk_hw_get() which uses
the newly introduced QMP_PCIE_PIPE_CLK & QMP_PCIE_PHY_AUX_CLK clock
IDs and also supports the legacy bindings by returning the PIPE clock
when #clock-cells=0.
Signed-off-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Small question below.
---
drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 78 ++++++++++++++++++++++++++++++--
1 file changed, 75 insertions(+), 3 deletions(-)
diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
index e8da2e9146dc..6c9a95e62429 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
@@ -22,6 +22,8 @@
#include <linux/reset.h>
#include <linux/slab.h>
+#include <dt-bindings/phy/phy-qcom-qmp.h>
+
#include "phy-qcom-qmp-common.h"
#include "phy-qcom-qmp.h"
@@ -2389,6 +2391,9 @@ struct qmp_phy_cfg {
/* QMP PHY pipe clock interface rate */
unsigned long pipe_clock_rate;
+
+ /* QMP PHY AUX clock interface rate */
+ unsigned long aux_clock_rate;
};
struct qmp_pcie {
@@ -2420,6 +2425,7 @@ struct qmp_pcie {
int mode;
struct clk_fixed_rate pipe_clk_fixed;
+ struct clk_fixed_rate aux_clk_fixed;
};
static inline void qphy_setbits(void __iomem *base, u32 offset, u32 val)
@@ -3686,6 +3692,62 @@ static int phy_pipe_clk_register(struct qmp_pcie *qmp, struct device_node *np)
return devm_clk_hw_register(qmp->dev, &fixed->hw);
}
+/*
+ * Register a fixed rate PHY aux clock.
+ *
+ * The <s>_phy_aux_clksrc generated by PHY goes to the GCC that gate
+ * controls it. The <s>_phy_aux_clk coming out of the GCC is requested
+ * by the PHY driver for its operations.
+ * We register the <s>_phy_aux_clksrc here. The gcc driver takes care
+ * of assigning this <s>_phy_aux_clksrc as parent to <s>_phy_aux_clk.
+ * Below picture shows this relationship.
+ *
+ * +---------------+
+ * | PHY block |<<---------------------------------------------+
+ * | | |
+ * | +-------+ | +-----+ |
+ * I/P---^-->| PLL |---^--->phy_aux_clksrc--->| GCC |--->phy_aux_clk---+
+ * clk | +-------+ | +-----+
+ * +---------------+
+ */
+static int phy_aux_clk_register(struct qmp_pcie *qmp, struct device_node *np)
+{
+ struct clk_fixed_rate *fixed = &qmp->aux_clk_fixed;
+ struct clk_init_data init = { };
+ int ret;
+
+ ret = of_property_read_string_index(np, "clock-output-names", 1, &init.name);
+ if (ret) {
+ dev_err(qmp->dev, "%pOFn: No clock-output-names index 1\n", np);
+ return ret;
+ }
+
+ init.ops = &clk_fixed_rate_ops;
+
+ fixed->fixed_rate = qmp->cfg->aux_clock_rate;
+ fixed->hw.init = &init;
+
+ return devm_clk_hw_register(qmp->dev, &fixed->hw);
+}
+
+static struct clk_hw *qmp_pcie_clk_hw_get(struct of_phandle_args *clkspec, void *data)
+{
+ struct qmp_pcie *qmp = data;
+
+ /* Support legacy bindings */
+ if (!clkspec->args_count)
+ return &qmp->pipe_clk_fixed.hw;
+
+ switch (clkspec->args[0]) {
+ case QMP_PCIE_PIPE_CLK:
+ return &qmp->pipe_clk_fixed.hw;
+ case QMP_PCIE_PHY_AUX_CLK:
+ return &qmp->aux_clk_fixed.hw;
Does the absence of the default case trigger a warning if compiled with W=1?
Nop it doesn't with GCC arm-gnu-toolchain-13.2.Rel1-x86_64-aarch64-none-linux-gnu + W=1 and with smatch and C=1
Neil
+ }
+
+ return ERR_PTR(-EINVAL);
+}
+
static int qmp_pcie_register_clocks(struct qmp_pcie *qmp, struct device_node *np)
{
int ret;
@@ -3694,9 +3756,19 @@ static int qmp_pcie_register_clocks(struct qmp_pcie *qmp, struct device_node *np
if (ret)
return ret;
- ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, &qmp->pipe_clk_fixed.hw);
- if (ret)
- return ret;
+ if (qmp->cfg->aux_clock_rate) {
+ ret = phy_aux_clk_register(qmp, np);
+ if (ret)
+ return ret;
+
+ ret = of_clk_add_hw_provider(np, qmp_pcie_clk_hw_get, qmp);
+ if (ret)
+ return ret;
+ } else {
+ ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, &qmp->pipe_clk_fixed.hw);
+ if (ret)
+ return ret;
+ }
/*
* Roll a devm action because the clock provider is the child node, but
--
2.34.1
