diff options
| author | Tony Lindgren <tony@atomide.com> | 2019-02-12 01:59:07 +0300 |
|---|---|---|
| committer | Stephen Boyd <sboyd@kernel.org> | 2019-02-22 01:11:23 +0300 |
| commit | 5ae51d67aec95f6f9386aa8dd5db424964895575 (patch) | |
| tree | 96982b4ac92ef812e521c7fbbedadccf5a968cbe /drivers/clk/clk-twl6040.c | |
| parent | 4e9a35d3d7965b90dcad72acf1933c6bdc16cb5d (diff) | |
| download | linux-5ae51d67aec95f6f9386aa8dd5db424964895575.tar.xz | |
clk: clk-twl6040: Fix imprecise external abort for pdmclk
I noticed that modprobe clk-twl6040 can fail after a cold boot with:
abe_cm:clk:0010:0: failed to enable
...
Unhandled fault: imprecise external abort (0x1406) at 0xbe896b20
WARNING: CPU: 1 PID: 29 at drivers/clk/clk.c:828 clk_core_disable_lock+0x18/0x24
...
(clk_core_disable_lock) from [<c0123534>] (_disable_clocks+0x18/0x90)
(_disable_clocks) from [<c0124040>] (_idle+0x17c/0x244)
(_idle) from [<c0125ad4>] (omap_hwmod_idle+0x24/0x44)
(omap_hwmod_idle) from [<c053a038>] (sysc_runtime_suspend+0x48/0x108)
(sysc_runtime_suspend) from [<c06084c4>] (__rpm_callback+0x144/0x1d8)
(__rpm_callback) from [<c0608578>] (rpm_callback+0x20/0x80)
(rpm_callback) from [<c0607034>] (rpm_suspend+0x120/0x694)
(rpm_suspend) from [<c0607a78>] (__pm_runtime_idle+0x60/0x84)
(__pm_runtime_idle) from [<c053aaf0>] (sysc_probe+0x874/0xf2c)
(sysc_probe) from [<c05fecd4>] (platform_drv_probe+0x48/0x98)
After searching around for a similar issue, I came across an earlier fix
that never got merged upstream in the Android tree for glass-omap-xrr02.
There is patch "MFD: twl6040-codec: Implement PDMCLK cold temp errata"
by Misael Lopez Cruz <misael.lopez@ti.com>.
Based on my observations, this fix is also needed when cold booting
devices, and not just for deeper idle modes. Since we now have a clock
driver for pdmclk, let's fix the issue in twl6040_pdmclk_prepare().
Cc: Misael Lopez Cruz <misael.lopez@ti.com>
Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Diffstat (limited to 'drivers/clk/clk-twl6040.c')
| -rw-r--r-- | drivers/clk/clk-twl6040.c | 53 |
1 files changed, 51 insertions, 2 deletions
diff --git a/drivers/clk/clk-twl6040.c b/drivers/clk/clk-twl6040.c index ea846f77750b..0cad5748bf0e 100644 --- a/drivers/clk/clk-twl6040.c +++ b/drivers/clk/clk-twl6040.c @@ -41,6 +41,43 @@ static int twl6040_pdmclk_is_prepared(struct clk_hw *hw) return pdmclk->enabled; } +static int twl6040_pdmclk_reset_one_clock(struct twl6040_pdmclk *pdmclk, + unsigned int reg) +{ + const u8 reset_mask = TWL6040_HPLLRST; /* Same for HPPLL and LPPLL */ + int ret; + + ret = twl6040_set_bits(pdmclk->twl6040, reg, reset_mask); + if (ret < 0) + return ret; + + ret = twl6040_clear_bits(pdmclk->twl6040, reg, reset_mask); + if (ret < 0) + return ret; + + return 0; +} + +/* + * TWL6040A2 Phoenix Audio IC erratum #6: "PDM Clock Generation Issue At + * Cold Temperature". This affects cold boot and deeper idle states it + * seems. The workaround consists of resetting HPPLL and LPPLL. + */ +static int twl6040_pdmclk_quirk_reset_clocks(struct twl6040_pdmclk *pdmclk) +{ + int ret; + + ret = twl6040_pdmclk_reset_one_clock(pdmclk, TWL6040_REG_HPPLLCTL); + if (ret) + return ret; + + ret = twl6040_pdmclk_reset_one_clock(pdmclk, TWL6040_REG_LPPLLCTL); + if (ret) + return ret; + + return 0; +} + static int twl6040_pdmclk_prepare(struct clk_hw *hw) { struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk, @@ -48,8 +85,20 @@ static int twl6040_pdmclk_prepare(struct clk_hw *hw) int ret; ret = twl6040_power(pdmclk->twl6040, 1); - if (!ret) - pdmclk->enabled = 1; + if (ret) + return ret; + + ret = twl6040_pdmclk_quirk_reset_clocks(pdmclk); + if (ret) + goto out_err; + + pdmclk->enabled = 1; + + return 0; + +out_err: + dev_err(pdmclk->dev, "%s: error %i\n", __func__, ret); + twl6040_power(pdmclk->twl6040, 0); return ret; } |