• Bryan O'Donoghue's avatar
    clk: qcom: msm8916: Fix the address location of pll->config_reg · f47ab3c2
    Bryan O'Donoghue authored
    During the process of debugging a processor derived from the msm8916 which
    we found the new processor was not starting one of its PLLs.
    
    After tracing the addresses and writes that downstream was doing and
    comparing to upstream it became obvious that we were writing to a different
    register location than downstream when trying to configure the PLL.
    
    This error is also present in upstream msm8916.
    
    As an example clk-pll.c::clk_pll_recalc_rate wants to write to
    pll->config_reg updating the bit-field POST_DIV_RATIO. That bit-field is
    defined in PLL_USER_CTL not in PLL_CONFIG_CTL. Taking the BIMC PLL as an
    example
    
    lm80-p0436-13_c_qc_snapdragon_410_processor_hrd.pdf
    
    0x01823010 GCC_BIMC_PLL_USER_CTL
    0x01823014 GCC_BIMC_PLL_CONFIG_CTL
    
    This pattern is repeated for gpll0, gpll1, gpll2 and bimc_pll.
    
    This error is likely not apparent since the bootloader will already have
    initialized these PLLs.
    
    This patch corrects the location of config_reg from PLL_CONFIG_CTL to
    PLL_USER_CTL for all relevant PLLs on msm8916.
    
    Fixes commit 3966fab8 ("clk: qcom: Add MSM8916 Global Clock Controller support")
    
    Cc: Georgi Djakov <georgi.djakov@linaro.org>
    Cc: Andy Gross <agross@kernel.org>
    Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
    Cc: Michael Turquette <mturquette@baylibre.com>
    Cc: Stephen Boyd <sboyd@kernel.org>
    Signed-off-by: default avatarBryan O'Donoghue <bryan.odonoghue@linaro.org>
    Link: https://lkml.kernel.org/r/20200329124116.4185447-1-bryan.odonoghue@linaro.orgSigned-off-by: default avatarStephen Boyd <sboyd@kernel.org>
    f47ab3c2
gcc-msm8916.c 81.2 KB