[PATCH v4 05/16] phy: qcom-qmp: Fix PHY block reset sequence

Manu Gautam
2018-01-03T11:28:38Z

PHY block or asynchronous reset requires signal
to be asserted before de-asserting. Driver is only
de-asserting signal which is already low, hence
reset operation is a no-op. Fix this by asserting
signal first. Also, resetting requires PHY clocks
to be turned ON only after reset is finished. Fix
that as well.

Signed-off-by: Manu Gautam <mgautam@codeaurora.org>
---
drivers/phy/qualcomm/phy-qcom-qmp.c | 28 +++++++++++++++++++---------
1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp.c b/drivers/phy/qualcomm/phy-qcom-qmp.c
index 1b82cea..ecff261 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp.c
@@ -752,13 +752,16 @@ static int qcom_qmp_phy_com_init(struct qcom_qmp *qmp)
goto err_reg_enable;
}

- ret = clk_bulk_prepare_enable(cfg->num_clks, qmp->clks);
- if (ret) {
- dev_err(qmp->dev, "failed to enable clks, err=%d\n", ret);
- goto err_clk_enable;
+ for (i = 0; i < cfg->num_resets; i++) {
+ ret = reset_control_assert(qmp->resets[i]);
+ if (ret) {
+ dev_err(qmp->dev, "%s reset assert failed\n",
+ cfg->reset_list[i]);
+ goto err_rst_assert;
+ }
}

- for (i = 0; i < cfg->num_resets; i++) {
+ for (i = cfg->num_resets - 1; i >= 0; i--) {
ret = reset_control_deassert(qmp->resets[i]);
if (ret) {
dev_err(qmp->dev, "%s reset deassert failed\n",
@@ -767,6 +770,12 @@ static int qcom_qmp_phy_com_init(struct qcom_qmp *qmp)
}
}

+ ret = clk_bulk_prepare_enable(cfg->num_clks, qmp->clks);
+ if (ret) {
+ dev_err(qmp->dev, "failed to enable clks, err=%d\n", ret);
+ goto err_rst;
+ }
+
if (cfg->has_phy_com_ctrl)
qphy_setbits(serdes, cfg->regs[QPHY_COM_POWER_DOWN_CONTROL],
SW_PWRDN);
@@ -791,7 +800,7 @@ static int qcom_qmp_phy_com_init(struct qcom_qmp *qmp)
if (ret) {
dev_err(qmp->dev,
"phy common block init timed-out\n");
- goto err_rst;
+ goto err_com_init;
}
}

@@ -799,11 +808,12 @@ static int qcom_qmp_phy_com_init(struct qcom_qmp *qmp)

return 0;

+err_com_init:
+ clk_bulk_disable_unprepare(cfg->num_clks, qmp->clks);
err_rst:
- while (--i >= 0)
+ while (++i < cfg->num_resets)
reset_control_assert(qmp->resets[i]);
- clk_bulk_disable_unprepare(cfg->num_clks, qmp->clks);
-err_clk_enable:
+err_rst_assert:
regulator_bulk_disable(cfg->num_vregs, qmp->vregs);
err_reg_enable:
mutex_unlock(&qmp->phy_mutex);