bcm27xx: update 6.1 patches from RPi foundation

[openwrt/openwrt.git] / target / linux / bcm27xx / patches-6.1 / 950-1257-i2c-designware-Use-SCL-rise-and-fall-times-in-DT.patch

diff --git a/target/linux/bcm27xx/patches-6.1/950-1257-i2c-designware-Use-SCL-rise-and-fall-times-in-DT.patch b/target/linux/bcm27xx/patches-6.1/950-1257-i2c-designware-Use-SCL-rise-and-fall-times-in-DT.patch
new file mode 100644 (file)
index 0000000..3aa719c
--- /dev/null
+++ b/target/linux/bcm27xx/patches-6.1/950-1257-i2c-designware-Use-SCL-rise-and-fall-times-in-DT.patch
@@ -0,0 +1,91 @@
+From b660279cc83aff2018cecfc3fb55757a8d64f607 Mon Sep 17 00:00:00 2001
+From: Phil Elwell <phil@raspberrypi.com>
+Date: Tue, 16 Jan 2024 15:54:22 +0000
+Subject: [PATCH 1257/1295] i2c: designware: Use SCL rise and fall times in DT
+
+Calculate the HCNT and LCNT values for all modes using the rise and
+fall times of SCL, the aim being a 50/50 mark/space ratio.
+
+Signed-off-by: Phil Elwell <phil@raspberrypi.com>
+---
+ drivers/i2c/busses/i2c-designware-master.c | 26 ++++++++++++++++++++++
+ 1 file changed, 26 insertions(+)
+
+--- a/drivers/i2c/busses/i2c-designware-master.c
++++ b/drivers/i2c/busses/i2c-designware-master.c
+@@ -16,6 +16,7 @@
+ #include <linux/i2c.h>
+ #include <linux/interrupt.h>
+ #include <linux/io.h>
++#include <linux/math64.h>
+ #include <linux/module.h>
+ #include <linux/pm_runtime.h>
+ #include <linux/regmap.h>
+@@ -37,6 +38,22 @@ static void i2c_dw_configure_fifo_master
+       regmap_write(dev->map, DW_IC_CON, dev->master_cfg);
+ }
+ 
++static u16 clock_calc(struct dw_i2c_dev *dev, bool want_high)
++{
++      struct i2c_timings *t = &dev->timings;
++      u32 wanted_speed = t->bus_freq_hz;
++      u32 clk_khz = i2c_dw_clk_rate(dev);
++      u32 extra_ns = want_high ? t->scl_fall_ns : t->scl_rise_ns;
++      u32 extra_cycles = (u32)div_u64((u64)clk_khz * extra_ns, 1000000);
++      u32 period = div_u64((u64)clk_khz * 1000 + wanted_speed - 1, wanted_speed);
++      u32 cycles = (period + want_high)/2 - extra_cycles;
++
++      if (cycles > 0xffff)
++              cycles = 0xffff;
++
++      return (u16)cycles;
++}
++
+ static int i2c_dw_set_timings_master(struct dw_i2c_dev *dev)
+ {
+       u32 comp_param1;
+@@ -44,6 +61,7 @@ static int i2c_dw_set_timings_master(str
+       struct i2c_timings *t = &dev->timings;
+       const char *fp_str = "";
+       u32 ic_clk;
++      u32 hcnt, lcnt;
+       int ret;
+ 
+       ret = i2c_dw_acquire_lock(dev);
+@@ -59,6 +77,9 @@ static int i2c_dw_set_timings_master(str
+       sda_falling_time = t->sda_fall_ns ?: 300; /* ns */
+       scl_falling_time = t->scl_fall_ns ?: 300; /* ns */
+ 
++      hcnt = clock_calc(dev, true);
++      lcnt = clock_calc(dev, false);
++
+       /* Calculate SCL timing parameters for standard mode if not set */
+       if (!dev->ss_hcnt || !dev->ss_lcnt) {
+               ic_clk = i2c_dw_clk_rate(dev);
+@@ -74,6 +95,8 @@ static int i2c_dw_set_timings_master(str
+                                       scl_falling_time,
+                                       0);     /* No offset */
+       }
++      dev->ss_hcnt = hcnt;
++      dev->ss_lcnt = lcnt;
+       dev_dbg(dev->dev, "Standard Mode HCNT:LCNT = %d:%d\n",
+               dev->ss_hcnt, dev->ss_lcnt);
+ 
+@@ -124,6 +147,8 @@ static int i2c_dw_set_timings_master(str
+                                       scl_falling_time,
+                                       0);     /* No offset */
+       }
++      dev->fs_hcnt = hcnt;
++      dev->fs_lcnt = lcnt;
+       dev_dbg(dev->dev, "Fast Mode%s HCNT:LCNT = %d:%d\n",
+               fp_str, dev->fs_hcnt, dev->fs_lcnt);
+ 
+@@ -152,6 +177,8 @@ static int i2c_dw_set_timings_master(str
+                                               scl_falling_time,
+                                               0);     /* No offset */
+               }
++              dev->hs_hcnt = hcnt;
++              dev->hs_lcnt = lcnt;
+               dev_dbg(dev->dev, "High Speed Mode HCNT:LCNT = %d:%d\n",
+                       dev->hs_hcnt, dev->hs_lcnt);
+       }