clk: rockchip: fix incorrect GATE bits for {c, g}pll_aclk_perihp_src on rk3399
authorXing Zheng <zhengxing@rock-chips.com>
Tue, 2 Aug 2016 07:19:57 +0000 (15:19 +0800)
committerHeiko Stuebner <heiko@sntech.de>
Fri, 12 Aug 2016 16:09:19 +0000 (18:09 +0200)
commit4608d96fb491125657fd8183a35921e4d4e27bc8
tree2f5c3037ab314fc01864177bfa2a72a699adb6c1
parent20c389e656a89e2302017bf3f499cb5a31a2a7ba
clk: rockchip: fix incorrect GATE bits for {c, g}pll_aclk_perihp_src on rk3399

Sorry to refer incorrect clock diagram, we double check it that the bits
configuration of the Xpll_aclk_perihp_src need to be fixed:
bit 1 - shows aclk_perihp_cpll_src_en
bit 0 - shows aclk_perihp_gpll_src_en

Through the testing that plug/unplug the USB ethernet cable on the RK3399 kevin board.

1. the hclk_host0 and hclk_host1 are endpoint clocks:
cpll --> G5[1] --> aclk_perihp_cpll_src --\              |--> hclk_host0
                                          | --> ... ---> |
gpll --> G5[0] --> aclk_perihp_gpll_src --/              |--> hclk_host1

2. there is no clock below the cpll_aclk_perihp_src,
   and the hclk_hostX are below the gpll_aclk_perihp_src:
    pll_cpll                              1            1   800000000          0 0
       cpll                               7           19   800000000          0 0
          cpll_aclk_perihp_src            0            0   800000000          0 0
...
    pll_gpll                              1            1   594000000          0 0
       gpll                              10           10   594000000          0 0
          gpll_aclk_perihp_src            2            2   594000000          0 0
                hclk_perihp               5            5    74250000          0 0
                   hclk_host1_arb         2            2    74250000          0 0
                   hclk_host1             2            2    74250000          0 0
                   hclk_host0_arb         2            2    74250000          0 0
                   hclk_host0             2            2    74250000          0 0

3. by default, G5[0] and G5[1] are enabled:
localhost ~ # mem r 0xff760314
0x000003e0

4. close the G5[1] (aclk_perihp_cpll_src), and plug/unplug USB ethernet cable,
   the DUT still works well:
localhost ~ # mem w 0xff760314 0xffff03e2
localhost ~ # mem r 0xff760314
0x000003e2
plug/unplug, the work statue is ok

5. close the G5[0] (aclk_perihp_gpll_src), , and plug/unplug USB ethernet cable,
   the DUT will be crashed:
localhost ~ # mem w 0xff760314 0xffff03e1
localhost ~ # mem r 0xff760314
0x000003e1
plug/unplug, the DUT is crashed

Summary:
bit 1 - shows aclk_perihp_cpll_src_en
bit 0 - shows aclk_perihp_gpll_src_en

Fixes: 3bd14ae9da91 ("clk: rockchip: fix incorrect parent for rk3399's {c,g}pll_aclk_perihp_src")
Signed-off-by: Xing Zheng <zhengxing@rock-chips.com>
[here the clock-documentation in the manual was actually stating the wrong
bits and thus only Xing's testing above revealed the issue]
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
drivers/clk/rockchip/clk-rk3399.c