| Message ID | 20200306100914.9022-1-patrick.delaunay@st.com |
|---|---|
| State | Accepted |
| Commit | c32446557627699cd17c93d1077b9d0466a81589 |
| Headers | show |
| Series | i2c: stm32f7_i2c: allows for any bus frequency | expand |
On 3/6/20 11:09 AM, Patrick Delaunay wrote: > From: Alain Volmat <alain.volmat at st.com> > > Do not limit to 3 (100KHz, 400KHz, 1MHz) bus frequencies, but > instead allow for any frequency. Depending on the requested > frequency (via the clock-frequency DT entry), use the spec > data from either Standard, Fast or Fast Plus mode. > > In order to do so, the driver do not use anymore spec identifier > by directly handle the requested frequency and from it retrieve > the corresponding spec data to be used for the computation > of the timing register. > > Signed-off-by: Alain Volmat <alain.volmat at st.com> > Reviewed-by: Patrick DELAUNAY <patrick.delaunay at st.com> > Signed-off-by: Patrick Delaunay <patrick.delaunay at st.com> > --- > > drivers/i2c/stm32f7_i2c.c | 105 +++++++++++++++++++++----------------- > 1 file changed, 59 insertions(+), 46 deletions(-) > > diff --git a/drivers/i2c/stm32f7_i2c.c b/drivers/i2c/stm32f7_i2c.c > index 7d046c1a1e..fc5c1221e1 100644 > --- a/drivers/i2c/stm32f7_i2c.c > +++ b/drivers/i2c/stm32f7_i2c.c > @@ -7,10 +7,10 @@ > #include <clk.h> > #include <dm.h> > #include <i2c.h> > -#include <malloc.h> > #include <reset.h> > > #include <dm/device.h> > +#include <linux/err.h> > #include <linux/io.h> > > /* STM32 I2C registers */ > @@ -145,7 +145,6 @@ struct stm32_i2c_spec { > > /** > * struct stm32_i2c_setup - private I2C timing setup parameters > - * @speed: I2C speed mode (standard, Fast Plus) > * @speed_freq: I2C speed frequency (Hz) > * @clock_src: I2C clock source frequency (Hz) > * @rise_time: Rise time (ns) > @@ -154,7 +153,6 @@ struct stm32_i2c_spec { > * @analog_filter: Analog filter delay (On/Off) > */ > struct stm32_i2c_setup { > - enum i2c_speed_mode speed; > u32 speed_freq; > u32 clock_src; > u32 rise_time; > @@ -184,10 +182,11 @@ struct stm32_i2c_priv { > struct stm32_i2c_regs *regs; > struct clk clk; > struct stm32_i2c_setup *setup; > - int speed; > + u32 speed; > }; > > static const struct stm32_i2c_spec i2c_specs[] = { > + /* Standard speed - 100 KHz */ > [IC_SPEED_MODE_STANDARD] = { > .rate = I2C_SPEED_STANDARD_RATE, > .rate_min = 8000, > @@ -200,6 +199,7 @@ static const struct stm32_i2c_spec i2c_specs[] = { > .l_min = 4700, > .h_min = 4000, > }, > + /* Fast speed - 400 KHz */ > [IC_SPEED_MODE_FAST] = { > .rate = I2C_SPEED_FAST_RATE, > .rate_min = 320000, > @@ -212,6 +212,7 @@ static const struct stm32_i2c_spec i2c_specs[] = { > .l_min = 1300, > .h_min = 600, > }, > + /* Fast Plus Speed - 1 MHz */ > [IC_SPEED_MODE_FAST_PLUS] = { > .rate = I2C_SPEED_FAST_PLUS_RATE, > .rate_min = 800000, > @@ -474,6 +475,7 @@ static int stm32_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, > } > > static int stm32_i2c_compute_solutions(struct stm32_i2c_setup *setup, > + const struct stm32_i2c_spec *specs, > struct list_head *solutions) > { > struct stm32_i2c_timings *v; > @@ -490,13 +492,13 @@ static int stm32_i2c_compute_solutions(struct stm32_i2c_setup *setup, > af_delay_max = setup->analog_filter ? > STM32_I2C_ANALOG_FILTER_DELAY_MAX : 0; > > - sdadel_min = i2c_specs[setup->speed].hddat_min + setup->fall_time - > + sdadel_min = specs->hddat_min + setup->fall_time - > af_delay_min - (setup->dnf + 3) * i2cclk; > > - sdadel_max = i2c_specs[setup->speed].vddat_max - setup->rise_time - > + sdadel_max = specs->vddat_max - setup->rise_time - > af_delay_max - (setup->dnf + 4) * i2cclk; > > - scldel_min = setup->rise_time + i2c_specs[setup->speed].sudat_min; > + scldel_min = setup->rise_time + specs->sudat_min; > > if (sdadel_min < 0) > sdadel_min = 0; > @@ -548,6 +550,7 @@ static int stm32_i2c_compute_solutions(struct stm32_i2c_setup *setup, > } > > static int stm32_i2c_choose_solution(struct stm32_i2c_setup *setup, > + const struct stm32_i2c_spec *specs, > struct list_head *solutions, > struct stm32_i2c_timings *s) > { > @@ -570,8 +573,8 @@ static int stm32_i2c_choose_solution(struct stm32_i2c_setup *setup, > dnf_delay = setup->dnf * i2cclk; > > tsync = af_delay_min + dnf_delay + (2 * i2cclk); > - clk_max = STM32_NSEC_PER_SEC / i2c_specs[setup->speed].rate_min; > - clk_min = STM32_NSEC_PER_SEC / i2c_specs[setup->speed].rate_max; > + clk_max = STM32_NSEC_PER_SEC / specs->rate_min; > + clk_min = STM32_NSEC_PER_SEC / specs->rate_max; > > /* > * Among Prescaler possibilities discovered above figures out SCL Low > @@ -589,7 +592,7 @@ static int stm32_i2c_choose_solution(struct stm32_i2c_setup *setup, > for (l = 0; l < STM32_SCLL_MAX; l++) { > u32 tscl_l = (l + 1) * prescaler + tsync; > > - if ((tscl_l < i2c_specs[setup->speed].l_min) || > + if (tscl_l < specs->l_min || > (i2cclk >= > ((tscl_l - af_delay_min - dnf_delay) / 4))) { > continue; > @@ -601,7 +604,7 @@ static int stm32_i2c_choose_solution(struct stm32_i2c_setup *setup, > setup->rise_time + setup->fall_time; > > if ((tscl >= clk_min) && (tscl <= clk_max) && > - (tscl_h >= i2c_specs[setup->speed].h_min) && > + (tscl_h >= specs->h_min) && > (i2cclk < tscl_h)) { > u32 clk_error; > > @@ -630,26 +633,40 @@ static int stm32_i2c_choose_solution(struct stm32_i2c_setup *setup, > return ret; > } > > +static const struct stm32_i2c_spec *get_specs(u32 rate) > +{ > + unsigned int i; > + > + for (i = 0; i < ARRAY_SIZE(i2c_specs); i++) > + if (rate <= i2c_specs[i].rate) > + return &i2c_specs[i]; > + > + /* NOT REACHED */ > + return ERR_PTR(-EINVAL); > +} > + > static int stm32_i2c_compute_timing(struct stm32_i2c_priv *i2c_priv, > struct stm32_i2c_setup *setup, > struct stm32_i2c_timings *output) > { > + const struct stm32_i2c_spec *specs; > struct stm32_i2c_timings *v, *_v; > struct list_head solutions; > int ret; > > - if (setup->speed >= ARRAY_SIZE(i2c_specs)) { > - pr_err("%s: speed out of bound {%d/%d}\n", __func__, > - setup->speed, ARRAY_SIZE(i2c_specs) - 1); > + specs = get_specs(setup->speed_freq); > + if (specs == ERR_PTR(-EINVAL)) { > + pr_err("%s: speed out of bound {%d}\n", __func__, > + setup->speed_freq); > return -EINVAL; > } > > - if ((setup->rise_time > i2c_specs[setup->speed].rise_max) || > - (setup->fall_time > i2c_specs[setup->speed].fall_max)) { > + if (setup->rise_time > specs->rise_max || > + setup->fall_time > specs->fall_max) { > pr_err("%s :timings out of bound Rise{%d>%d}/Fall{%d>%d}\n", > __func__, > - setup->rise_time, i2c_specs[setup->speed].rise_max, > - setup->fall_time, i2c_specs[setup->speed].fall_max); > + setup->rise_time, specs->rise_max, > + setup->fall_time, specs->fall_max); > return -EINVAL; > } > > @@ -659,18 +676,12 @@ static int stm32_i2c_compute_timing(struct stm32_i2c_priv *i2c_priv, > return -EINVAL; > } > > - if (setup->speed_freq > i2c_specs[setup->speed].rate) { > - pr_err("%s: Freq {%d/%d}\n", __func__, > - setup->speed_freq, i2c_specs[setup->speed].rate); > - return -EINVAL; > - } > - > INIT_LIST_HEAD(&solutions); > - ret = stm32_i2c_compute_solutions(setup, &solutions); > + ret = stm32_i2c_compute_solutions(setup, specs, &solutions); > if (ret) > goto exit; > > - ret = stm32_i2c_choose_solution(setup, &solutions, output); > + ret = stm32_i2c_choose_solution(setup, specs, &solutions, output); > if (ret) > goto exit; > > @@ -689,14 +700,24 @@ exit: > return ret; > } > > +static u32 get_lower_rate(u32 rate) > +{ > + int i; > + > + for (i = ARRAY_SIZE(i2c_specs) - 1; i >= 0; i--) > + if (rate > i2c_specs[i].rate) > + return i2c_specs[i].rate; > + > + return i2c_specs[0].rate; > +} > + > static int stm32_i2c_setup_timing(struct stm32_i2c_priv *i2c_priv, > struct stm32_i2c_timings *timing) > { > struct stm32_i2c_setup *setup = i2c_priv->setup; > int ret = 0; > > - setup->speed = i2c_priv->speed; > - setup->speed_freq = i2c_specs[setup->speed].rate; > + setup->speed_freq = i2c_priv->speed; > setup->clock_src = clk_get_rate(&i2c_priv->clk); > > if (!setup->clock_src) { > @@ -709,13 +730,11 @@ static int stm32_i2c_setup_timing(struct stm32_i2c_priv *i2c_priv, > if (ret) { > debug("%s: failed to compute I2C timings.\n", > __func__); > - if (i2c_priv->speed > IC_SPEED_MODE_STANDARD) { > - i2c_priv->speed--; > - setup->speed = i2c_priv->speed; > + if (setup->speed_freq > I2C_SPEED_STANDARD_RATE) { > setup->speed_freq = > - i2c_specs[setup->speed].rate; > + get_lower_rate(setup->speed_freq); > debug("%s: downgrade I2C Speed Freq to (%i)\n", > - __func__, i2c_specs[setup->speed].rate); > + __func__, setup->speed_freq); > } else { > break; > } > @@ -727,13 +746,15 @@ static int stm32_i2c_setup_timing(struct stm32_i2c_priv *i2c_priv, > return ret; > } > > - debug("%s: I2C Speed(%i), Freq(%i), Clk Source(%i)\n", __func__, > - setup->speed, setup->speed_freq, setup->clock_src); > + debug("%s: I2C Freq(%i), Clk Source(%i)\n", __func__, > + setup->speed_freq, setup->clock_src); > debug("%s: I2C Rise(%i) and Fall(%i) Time\n", __func__, > setup->rise_time, setup->fall_time); > debug("%s: I2C Analog Filter(%s), DNF(%i)\n", __func__, > setup->analog_filter ? "On" : "Off", setup->dnf); > > + i2c_priv->speed = setup->speed_freq; > + > return 0; > } > > @@ -773,21 +794,13 @@ static int stm32_i2c_set_bus_speed(struct udevice *bus, unsigned int speed) > { > struct stm32_i2c_priv *i2c_priv = dev_get_priv(bus); > > - switch (speed) { > - case I2C_SPEED_STANDARD_RATE: > - i2c_priv->speed = IC_SPEED_MODE_STANDARD; > - break; > - case I2C_SPEED_FAST_RATE: > - i2c_priv->speed = IC_SPEED_MODE_FAST; > - break; > - case I2C_SPEED_FAST_PLUS_RATE: > - i2c_priv->speed = IC_SPEED_MODE_FAST_PLUS; > - break; > - default: > + if (speed > I2C_SPEED_FAST_PLUS_RATE) { > debug("%s: Speed %d not supported\n", __func__, speed); > return -EINVAL; > } > > + i2c_priv->speed = speed; > + > return stm32_i2c_hw_config(i2c_priv); > } > Acked-by: Patrice Chotard <patrice.chotard at st.com> Thanks Patrice
Hi > From: Patrick DELAUNAY <patrick.delaunay at st.com> > Sent: vendredi 6 mars 2020 11:09 > > From: Alain Volmat <alain.volmat at st.com> > > Do not limit to 3 (100KHz, 400KHz, 1MHz) bus frequencies, but instead allow for > any frequency. Depending on the requested frequency (via the clock-frequency > DT entry), use the spec data from either Standard, Fast or Fast Plus mode. > > In order to do so, the driver do not use anymore spec identifier by directly handle > the requested frequency and from it retrieve the corresponding spec data to be > used for the computation of the timing register. > > Signed-off-by: Alain Volmat <alain.volmat at st.com> > Reviewed-by: Patrick DELAUNAY <patrick.delaunay at st.com> > Signed-off-by: Patrick Delaunay <patrick.delaunay at st.com> > --- Applied to u-boot-stm/next, thanks! Regards Patrick
diff --git a/drivers/i2c/stm32f7_i2c.c b/drivers/i2c/stm32f7_i2c.c index 7d046c1a1e..fc5c1221e1 100644 --- a/drivers/i2c/stm32f7_i2c.c +++ b/drivers/i2c/stm32f7_i2c.c @@ -7,10 +7,10 @@ #include <clk.h> #include <dm.h> #include <i2c.h> -#include <malloc.h> #include <reset.h> #include <dm/device.h> +#include <linux/err.h> #include <linux/io.h> /* STM32 I2C registers */ @@ -145,7 +145,6 @@ struct stm32_i2c_spec { /** * struct stm32_i2c_setup - private I2C timing setup parameters - * @speed: I2C speed mode (standard, Fast Plus) * @speed_freq: I2C speed frequency (Hz) * @clock_src: I2C clock source frequency (Hz) * @rise_time: Rise time (ns) @@ -154,7 +153,6 @@ struct stm32_i2c_spec { * @analog_filter: Analog filter delay (On/Off) */ struct stm32_i2c_setup { - enum i2c_speed_mode speed; u32 speed_freq; u32 clock_src; u32 rise_time; @@ -184,10 +182,11 @@ struct stm32_i2c_priv { struct stm32_i2c_regs *regs; struct clk clk; struct stm32_i2c_setup *setup; - int speed; + u32 speed; }; static const struct stm32_i2c_spec i2c_specs[] = { + /* Standard speed - 100 KHz */ [IC_SPEED_MODE_STANDARD] = { .rate = I2C_SPEED_STANDARD_RATE, .rate_min = 8000, @@ -200,6 +199,7 @@ static const struct stm32_i2c_spec i2c_specs[] = { .l_min = 4700, .h_min = 4000, }, + /* Fast speed - 400 KHz */ [IC_SPEED_MODE_FAST] = { .rate = I2C_SPEED_FAST_RATE, .rate_min = 320000, @@ -212,6 +212,7 @@ static const struct stm32_i2c_spec i2c_specs[] = { .l_min = 1300, .h_min = 600, }, + /* Fast Plus Speed - 1 MHz */ [IC_SPEED_MODE_FAST_PLUS] = { .rate = I2C_SPEED_FAST_PLUS_RATE, .rate_min = 800000, @@ -474,6 +475,7 @@ static int stm32_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, } static int stm32_i2c_compute_solutions(struct stm32_i2c_setup *setup, + const struct stm32_i2c_spec *specs, struct list_head *solutions) { struct stm32_i2c_timings *v; @@ -490,13 +492,13 @@ static int stm32_i2c_compute_solutions(struct stm32_i2c_setup *setup, af_delay_max = setup->analog_filter ? STM32_I2C_ANALOG_FILTER_DELAY_MAX : 0; - sdadel_min = i2c_specs[setup->speed].hddat_min + setup->fall_time - + sdadel_min = specs->hddat_min + setup->fall_time - af_delay_min - (setup->dnf + 3) * i2cclk; - sdadel_max = i2c_specs[setup->speed].vddat_max - setup->rise_time - + sdadel_max = specs->vddat_max - setup->rise_time - af_delay_max - (setup->dnf + 4) * i2cclk; - scldel_min = setup->rise_time + i2c_specs[setup->speed].sudat_min; + scldel_min = setup->rise_time + specs->sudat_min; if (sdadel_min < 0) sdadel_min = 0; @@ -548,6 +550,7 @@ static int stm32_i2c_compute_solutions(struct stm32_i2c_setup *setup, } static int stm32_i2c_choose_solution(struct stm32_i2c_setup *setup, + const struct stm32_i2c_spec *specs, struct list_head *solutions, struct stm32_i2c_timings *s) { @@ -570,8 +573,8 @@ static int stm32_i2c_choose_solution(struct stm32_i2c_setup *setup, dnf_delay = setup->dnf * i2cclk; tsync = af_delay_min + dnf_delay + (2 * i2cclk); - clk_max = STM32_NSEC_PER_SEC / i2c_specs[setup->speed].rate_min; - clk_min = STM32_NSEC_PER_SEC / i2c_specs[setup->speed].rate_max; + clk_max = STM32_NSEC_PER_SEC / specs->rate_min; + clk_min = STM32_NSEC_PER_SEC / specs->rate_max; /* * Among Prescaler possibilities discovered above figures out SCL Low @@ -589,7 +592,7 @@ static int stm32_i2c_choose_solution(struct stm32_i2c_setup *setup, for (l = 0; l < STM32_SCLL_MAX; l++) { u32 tscl_l = (l + 1) * prescaler + tsync; - if ((tscl_l < i2c_specs[setup->speed].l_min) || + if (tscl_l < specs->l_min || (i2cclk >= ((tscl_l - af_delay_min - dnf_delay) / 4))) { continue; @@ -601,7 +604,7 @@ static int stm32_i2c_choose_solution(struct stm32_i2c_setup *setup, setup->rise_time + setup->fall_time; if ((tscl >= clk_min) && (tscl <= clk_max) && - (tscl_h >= i2c_specs[setup->speed].h_min) && + (tscl_h >= specs->h_min) && (i2cclk < tscl_h)) { u32 clk_error; @@ -630,26 +633,40 @@ static int stm32_i2c_choose_solution(struct stm32_i2c_setup *setup, return ret; } +static const struct stm32_i2c_spec *get_specs(u32 rate) +{ + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(i2c_specs); i++) + if (rate <= i2c_specs[i].rate) + return &i2c_specs[i]; + + /* NOT REACHED */ + return ERR_PTR(-EINVAL); +} + static int stm32_i2c_compute_timing(struct stm32_i2c_priv *i2c_priv, struct stm32_i2c_setup *setup, struct stm32_i2c_timings *output) { + const struct stm32_i2c_spec *specs; struct stm32_i2c_timings *v, *_v; struct list_head solutions; int ret; - if (setup->speed >= ARRAY_SIZE(i2c_specs)) { - pr_err("%s: speed out of bound {%d/%d}\n", __func__, - setup->speed, ARRAY_SIZE(i2c_specs) - 1); + specs = get_specs(setup->speed_freq); + if (specs == ERR_PTR(-EINVAL)) { + pr_err("%s: speed out of bound {%d}\n", __func__, + setup->speed_freq); return -EINVAL; } - if ((setup->rise_time > i2c_specs[setup->speed].rise_max) || - (setup->fall_time > i2c_specs[setup->speed].fall_max)) { + if (setup->rise_time > specs->rise_max || + setup->fall_time > specs->fall_max) { pr_err("%s :timings out of bound Rise{%d>%d}/Fall{%d>%d}\n", __func__, - setup->rise_time, i2c_specs[setup->speed].rise_max, - setup->fall_time, i2c_specs[setup->speed].fall_max); + setup->rise_time, specs->rise_max, + setup->fall_time, specs->fall_max); return -EINVAL; } @@ -659,18 +676,12 @@ static int stm32_i2c_compute_timing(struct stm32_i2c_priv *i2c_priv, return -EINVAL; } - if (setup->speed_freq > i2c_specs[setup->speed].rate) { - pr_err("%s: Freq {%d/%d}\n", __func__, - setup->speed_freq, i2c_specs[setup->speed].rate); - return -EINVAL; - } - INIT_LIST_HEAD(&solutions); - ret = stm32_i2c_compute_solutions(setup, &solutions); + ret = stm32_i2c_compute_solutions(setup, specs, &solutions); if (ret) goto exit; - ret = stm32_i2c_choose_solution(setup, &solutions, output); + ret = stm32_i2c_choose_solution(setup, specs, &solutions, output); if (ret) goto exit; @@ -689,14 +700,24 @@ exit: return ret; } +static u32 get_lower_rate(u32 rate) +{ + int i; + + for (i = ARRAY_SIZE(i2c_specs) - 1; i >= 0; i--) + if (rate > i2c_specs[i].rate) + return i2c_specs[i].rate; + + return i2c_specs[0].rate; +} + static int stm32_i2c_setup_timing(struct stm32_i2c_priv *i2c_priv, struct stm32_i2c_timings *timing) { struct stm32_i2c_setup *setup = i2c_priv->setup; int ret = 0; - setup->speed = i2c_priv->speed; - setup->speed_freq = i2c_specs[setup->speed].rate; + setup->speed_freq = i2c_priv->speed; setup->clock_src = clk_get_rate(&i2c_priv->clk); if (!setup->clock_src) { @@ -709,13 +730,11 @@ static int stm32_i2c_setup_timing(struct stm32_i2c_priv *i2c_priv, if (ret) { debug("%s: failed to compute I2C timings.\n", __func__); - if (i2c_priv->speed > IC_SPEED_MODE_STANDARD) { - i2c_priv->speed--; - setup->speed = i2c_priv->speed; + if (setup->speed_freq > I2C_SPEED_STANDARD_RATE) { setup->speed_freq = - i2c_specs[setup->speed].rate; + get_lower_rate(setup->speed_freq); debug("%s: downgrade I2C Speed Freq to (%i)\n", - __func__, i2c_specs[setup->speed].rate); + __func__, setup->speed_freq); } else { break; } @@ -727,13 +746,15 @@ static int stm32_i2c_setup_timing(struct stm32_i2c_priv *i2c_priv, return ret; } - debug("%s: I2C Speed(%i), Freq(%i), Clk Source(%i)\n", __func__, - setup->speed, setup->speed_freq, setup->clock_src); + debug("%s: I2C Freq(%i), Clk Source(%i)\n", __func__, + setup->speed_freq, setup->clock_src); debug("%s: I2C Rise(%i) and Fall(%i) Time\n", __func__, setup->rise_time, setup->fall_time); debug("%s: I2C Analog Filter(%s), DNF(%i)\n", __func__, setup->analog_filter ? "On" : "Off", setup->dnf); + i2c_priv->speed = setup->speed_freq; + return 0; } @@ -773,21 +794,13 @@ static int stm32_i2c_set_bus_speed(struct udevice *bus, unsigned int speed) { struct stm32_i2c_priv *i2c_priv = dev_get_priv(bus); - switch (speed) { - case I2C_SPEED_STANDARD_RATE: - i2c_priv->speed = IC_SPEED_MODE_STANDARD; - break; - case I2C_SPEED_FAST_RATE: - i2c_priv->speed = IC_SPEED_MODE_FAST; - break; - case I2C_SPEED_FAST_PLUS_RATE: - i2c_priv->speed = IC_SPEED_MODE_FAST_PLUS; - break; - default: + if (speed > I2C_SPEED_FAST_PLUS_RATE) { debug("%s: Speed %d not supported\n", __func__, speed); return -EINVAL; } + i2c_priv->speed = speed; + return stm32_i2c_hw_config(i2c_priv); }