diff options
Diffstat (limited to 'drivers/clk/imx/clk-composite-7ulp.c')
| -rw-r--r-- | drivers/clk/imx/clk-composite-7ulp.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/drivers/clk/imx/clk-composite-7ulp.c b/drivers/clk/imx/clk-composite-7ulp.c index e208ddc51133..37d2fc197be6 100644 --- a/drivers/clk/imx/clk-composite-7ulp.c +++ b/drivers/clk/imx/clk-composite-7ulp.c @@ -7,6 +7,7 @@ #include <linux/bits.h> #include <linux/clk-provider.h> +#include <linux/delay.h> #include <linux/err.h> #include <linux/io.h> #include <linux/slab.h> @@ -14,6 +15,7 @@ #include "../clk-fractional-divider.h" #include "clk.h" +#define PCG_PR_MASK BIT(31) #define PCG_PCS_SHIFT 24 #define PCG_PCS_MASK 0x7 #define PCG_CGC_SHIFT 30 @@ -35,6 +37,9 @@ static int pcc_gate_enable(struct clk_hw *hw) if (ret) return ret; + /* Make sure the IP's clock is ready before release reset */ + udelay(1); + spin_lock_irqsave(gate->lock, flags); /* * release the sw reset for peripherals associated with @@ -46,6 +51,15 @@ static int pcc_gate_enable(struct clk_hw *hw) spin_unlock_irqrestore(gate->lock, flags); + /* + * Read back the register to make sure the previous write has been + * done in the target HW register. For IP like GPU, after deassert + * the reset, need to wait for a while to make sure the sync reset + * is done + */ + readl(gate->reg); + udelay(1); + return 0; } @@ -78,6 +92,12 @@ static struct clk_hw *imx_ulp_clk_hw_composite(const char *name, struct clk_hw *hw; u32 val; + val = readl(reg); + if (!(val & PCG_PR_MASK)) { + pr_info("PCC PR is 0 for clk:%s, bypass\n", name); + return NULL; + } + if (mux_present) { mux = kzalloc(sizeof(*mux), GFP_KERNEL); if (!mux) |