diff options
| -rw-r--r-- | drivers/base/regmap/regmap.c | 54 | ||||
| -rw-r--r-- | include/linux/regmap.h | 5 |
2 files changed, 52 insertions, 7 deletions
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index 2cbb4502747d..b3a5aa5cd580 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -18,6 +18,7 @@ #include <linux/of.h> #include <linux/rbtree.h> #include <linux/sched.h> +#include <linux/delay.h> #define CREATE_TRACE_POINTS #include "trace.h" @@ -1807,10 +1808,12 @@ static int _regmap_range_multi_paged_reg_write(struct regmap *map, int i, n; struct reg_sequence *base; unsigned int this_page = 0; + unsigned int page_change = 0; /* * the set of registers are not neccessarily in order, but * since the order of write must be preserved this algorithm - * chops the set each time the page changes + * chops the set each time the page changes. This also applies + * if there is a delay required at any point in the sequence. */ base = regs; for (i = 0, n = 0; i < num_regs; i++, n++) { @@ -1826,16 +1829,48 @@ static int _regmap_range_multi_paged_reg_write(struct regmap *map, this_page = win_page; if (win_page != this_page) { this_page = win_page; + page_change = 1; + } + } + + /* If we have both a page change and a delay make sure to + * write the regs and apply the delay before we change the + * page. + */ + + if (page_change || regs[i].delay_us) { + + /* For situations where the first write requires + * a delay we need to make sure we don't call + * raw_multi_reg_write with n=0 + * This can't occur with page breaks as we + * never write on the first iteration + */ + if (regs[i].delay_us && i == 0) + n = 1; + ret = _regmap_raw_multi_reg_write(map, base, n); if (ret != 0) return ret; + + if (regs[i].delay_us) + udelay(regs[i].delay_us); + base += n; n = 0; - } - ret = _regmap_select_page(map, &base[n].reg, range, 1); - if (ret != 0) - return ret; + + if (page_change) { + ret = _regmap_select_page(map, + &base[n].reg, + range, 1); + if (ret != 0) + return ret; + + page_change = 0; + } + } + } if (n > 0) return _regmap_raw_multi_reg_write(map, base, n); @@ -1854,6 +1889,9 @@ static int _regmap_multi_reg_write(struct regmap *map, ret = _regmap_write(map, regs[i].reg, regs[i].def); if (ret != 0) return ret; + + if (regs[i].delay_us) + udelay(regs[i].delay_us); } return 0; } @@ -1893,8 +1931,12 @@ static int _regmap_multi_reg_write(struct regmap *map, for (i = 0; i < num_regs; i++) { unsigned int reg = regs[i].reg; struct regmap_range_node *range; + + /* Coalesce all the writes between a page break or a delay + * in a sequence + */ range = _regmap_range_lookup(map, reg); - if (range) { + if (range || regs[i].delay_us) { size_t len = sizeof(struct reg_sequence)*num_regs; struct reg_sequence *base = kmemdup(regs, len, GFP_KERNEL); diff --git a/include/linux/regmap.h b/include/linux/regmap.h index c9ef2ec69142..5a7cf2136c81 100644 --- a/include/linux/regmap.h +++ b/include/linux/regmap.h @@ -51,14 +51,17 @@ struct reg_default { }; /** - * Register/value pairs for sequences of writes + * Register/value pairs for sequences of writes with an optional delay in + * microseconds to be applied after each write. * * @reg: Register address. * @def: Register value. + * @delay_us: Delay to be applied after the register write in microseconds */ struct reg_sequence { unsigned int reg; unsigned int def; + unsigned int delay_us; }; #ifdef CONFIG_REGMAP |