Hi Daniel,
Nice driver, please find my comments below.
Once fixed, you can add:
Reviewed-by: Maxime Coquelin <mcoquelin.stm32@xxxxxxxxx>
On 05/30/2015 09:54 AM, Daniel Thompson wrote:
The driver supports decoding and statically modelling PLL state (i.e.
we inherit state from bootloader) and provides support for all
peripherals that support simple one-bit gated clocks. The covers all
peripherals whose clocks come from the AHB, APB1 or APB2 buses.
It has been tested (for non-regression only) on an STM32F429I-Discovery
boards. The clock counts for TIM2, USART1 and SYSTICK are all set correctly
and time and the wall clock looks OK when checked with a stopwatch.
Signed-off-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
---
drivers/clk/Makefile | 1 +
drivers/clk/clk-stm32f4.c | 364 ++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 365 insertions(+)
create mode 100644 drivers/clk/clk-stm32f4.c
...
diff --git a/drivers/clk/clk-stm32f4.c b/drivers/clk/clk-stm32f4.c
new file mode 100644
index 0000000..68f9962
--- /dev/null
+++ b/drivers/clk/clk-stm32f4.c
@@ -0,0 +1,364 @@
...
+/*
+ * Converts the primary and secondary indices (as they appear in DT) to an
+ * offset into our struct clock array.
+ */
+static unsigned int stm32f4_rcc_lookup_clk_idx(u8 primary, u8 secondary)
+{
+ u64 table[ARRAY_SIZE(stm32f42xx_gate_map)];
+
+ if (primary == 1) {
+ BUG_ON(secondary > FCLK);
Maybe the function could return a signed int, an propagate errors
instead of using BUG_ON?
+ return secondary;
+ }
+
+ memcpy(table, stm32f42xx_gate_map, sizeof(table));
+
+ /* only bits set in table can be used as indices */
+ BUG_ON(secondary > 8 * sizeof(table) ||
+ 0 == (table[BIT_ULL_WORD(secondary)] & BIT_ULL_MASK(secondary)));
Ditto.
+
+ /* mask out bits above our current index */
+ table[BIT_ULL_WORD(secondary)] &=
+ GENMASK_ULL(secondary % BITS_PER_LONG_LONG, 0);
+
+ return FCLK + hweight64(table[0]) +
+ (BIT_ULL_WORD(secondary) >= 1 ? hweight64(table[1]) : 0) +
+ (BIT_ULL_WORD(secondary) >= 2 ? hweight64(table[2]) : 0);
+}
+
+struct clk *stm32f4_rcc_lookup_clk(struct of_phandle_args *clkspec, void *data)
+{
+ return clks[stm32f4_rcc_lookup_clk_idx(clkspec->args[0],
+ clkspec->args[1])];
If stm32f4_rcc_lookup_clk_idx() returns an error, you could propagate it
using ERR_PTR().
+}
+
+static const char __initdata *sys_parents[] = { "hsi", NULL, "pll" };
+
+static struct clk_div_table ahb_div_table[] = {
Should be const.
+ { 0x0, 1 }, { 0x1, 1 }, { 0x2, 1 }, { 0x3, 1 },
+ { 0x4, 1 }, { 0x5, 1 }, { 0x6, 1 }, { 0x7, 1 },
+ { 0x8, 2 }, { 0x9, 4 }, { 0xa, 8 }, { 0xb, 16 },
+ { 0xc, 64 }, { 0xd, 128 }, { 0xe, 256 }, { 0xf, 512 },
+ { 0 },
+};
+
+static struct clk_div_table apb_div_table[] = {
Ditto.
+ { 0, 1 }, { 0, 1 }, { 0, 1 }, { 0, 1 },
+ { 4, 2 }, { 5, 4 }, { 6, 8 }, { 7, 16 },
+ { 0 },
+};
Thanks!
Maxime
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