diff options
| -rw-r--r-- | drivers/mtd/nand/raw/denali_dt.c | 40 |
1 files changed, 39 insertions, 1 deletions
diff --git a/drivers/mtd/nand/raw/denali_dt.c b/drivers/mtd/nand/raw/denali_dt.c index 699255fb2dd8..f08740ae282b 100644 --- a/drivers/mtd/nand/raw/denali_dt.c +++ b/drivers/mtd/nand/raw/denali_dt.c @@ -6,6 +6,7 @@ */ #include <linux/clk.h> +#include <linux/delay.h> #include <linux/err.h> #include <linux/io.h> #include <linux/ioport.h> @@ -14,6 +15,7 @@ #include <linux/of.h> #include <linux/of_device.h> #include <linux/platform_device.h> +#include <linux/reset.h> #include "denali.h" @@ -22,6 +24,8 @@ struct denali_dt { struct clk *clk; /* core clock */ struct clk *clk_x; /* bus interface clock */ struct clk *clk_ecc; /* ECC circuit clock */ + struct reset_control *rst; /* core reset */ + struct reset_control *rst_reg; /* register reset */ }; struct denali_dt_data { @@ -157,6 +161,14 @@ static int denali_dt_probe(struct platform_device *pdev) if (IS_ERR(dt->clk_ecc)) return PTR_ERR(dt->clk_ecc); + dt->rst = devm_reset_control_get_optional_shared(dev, "nand"); + if (IS_ERR(dt->rst)) + return PTR_ERR(dt->rst); + + dt->rst_reg = devm_reset_control_get_optional_shared(dev, "reg"); + if (IS_ERR(dt->rst_reg)) + return PTR_ERR(dt->rst_reg); + ret = clk_prepare_enable(dt->clk); if (ret) return ret; @@ -172,10 +184,30 @@ static int denali_dt_probe(struct platform_device *pdev) denali->clk_rate = clk_get_rate(dt->clk); denali->clk_x_rate = clk_get_rate(dt->clk_x); - ret = denali_init(denali); + /* + * Deassert the register reset, and the core reset in this order. + * Deasserting the core reset while the register reset is asserted + * will cause unpredictable behavior in the controller. + */ + ret = reset_control_deassert(dt->rst_reg); if (ret) goto out_disable_clk_ecc; + ret = reset_control_deassert(dt->rst); + if (ret) + goto out_assert_rst_reg; + + /* + * When the reset is deasserted, the initialization sequence is kicked + * (bootstrap process). The driver must wait until it finished. + * Otherwise, it will result in unpredictable behavior. + */ + usleep_range(200, 1000); + + ret = denali_init(denali); + if (ret) + goto out_assert_rst; + for_each_child_of_node(dev->of_node, np) { ret = denali_dt_chip_init(denali, np); if (ret) { @@ -190,6 +222,10 @@ static int denali_dt_probe(struct platform_device *pdev) out_remove_denali: denali_remove(denali); +out_assert_rst: + reset_control_assert(dt->rst); +out_assert_rst_reg: + reset_control_assert(dt->rst_reg); out_disable_clk_ecc: clk_disable_unprepare(dt->clk_ecc); out_disable_clk_x: @@ -205,6 +241,8 @@ static int denali_dt_remove(struct platform_device *pdev) struct denali_dt *dt = platform_get_drvdata(pdev); denali_remove(&dt->controller); + reset_control_assert(dt->rst); + reset_control_assert(dt->rst_reg); clk_disable_unprepare(dt->clk_ecc); clk_disable_unprepare(dt->clk_x); clk_disable_unprepare(dt->clk); |