[PATCH v2 4/9] stm32mp1: clk: configure pll1 with OPP
Patrick Delaunay
patrick.delaunay at st.com
Mon May 25 12:19:44 CEST 2020
The PLL1 node (st,pll1) is optional in device tree, the max supported
frequency define in OPP node is used when the node is absent.
Signed-off-by: Patrick Delaunay <patrick.delaunay at st.com>
Reviewed-by: Patrice Chotard <patrice.chotard at st.com>
---
Changes in v2: None
.../clock/st,stm32mp1.txt | 4 +
drivers/clk/clk_stm32mp1.c | 290 ++++++++++++++++--
2 files changed, 266 insertions(+), 28 deletions(-)
diff --git a/doc/device-tree-bindings/clock/st,stm32mp1.txt b/doc/device-tree-bindings/clock/st,stm32mp1.txt
index a3d427911d..4d4136d2fc 100644
--- a/doc/device-tree-bindings/clock/st,stm32mp1.txt
+++ b/doc/device-tree-bindings/clock/st,stm32mp1.txt
@@ -87,6 +87,10 @@ Optional Properties:
are listed with associated reg 0 to 3.
PLLx is off when the associated node is absent or deactivated.
+ For PLL1, when the node is absent, the frequency of the OPP node is used
+ to compute the PLL setting (see compatible "operating-points-v2" in
+ opp/opp.txt for details).
+
Here are the available properties for each PLL node:
- compatible: should be "st,stm32mp1-pll"
diff --git a/drivers/clk/clk_stm32mp1.c b/drivers/clk/clk_stm32mp1.c
index 0d0ea43fd2..b48c835bc3 100644
--- a/drivers/clk/clk_stm32mp1.c
+++ b/drivers/clk/clk_stm32mp1.c
@@ -14,6 +14,7 @@
#include <vsprintf.h>
#include <linux/io.h>
#include <linux/iopoll.h>
+#include <asm/arch/sys_proto.h>
#include <dt-bindings/clock/stm32mp1-clks.h>
#include <dt-bindings/clock/stm32mp1-clksrc.h>
@@ -641,8 +642,18 @@ static const struct stm32mp1_clk_sel stm32mp1_clk_sel[_PARENT_SEL_NB] = {
};
#ifdef STM32MP1_CLOCK_TREE_INIT
+
/* define characteristic of PLL according type */
+#define DIVM_MIN 0
+#define DIVM_MAX 63
#define DIVN_MIN 24
+#define DIVP_MIN 0
+#define DIVP_MAX 127
+#define FRAC_MAX 8192
+
+#define PLL1600_VCO_MIN 800000000
+#define PLL1600_VCO_MAX 1600000000
+
static const struct stm32mp1_pll stm32mp1_pll[PLL_TYPE_NB] = {
[PLL_800] = {
.refclk_min = 4,
@@ -1187,6 +1198,208 @@ static ulong stm32mp1_clk_get_rate(struct clk *clk)
}
#ifdef STM32MP1_CLOCK_TREE_INIT
+
+bool stm32mp1_supports_opp(u32 opp_id, u32 cpu_type)
+{
+ unsigned int id;
+
+ switch (opp_id) {
+ case 1:
+ case 2:
+ id = opp_id;
+ break;
+ default:
+ id = 1; /* default value */
+ break;
+ }
+
+ switch (cpu_type) {
+ case CPU_STM32MP157Fxx:
+ case CPU_STM32MP157Dxx:
+ case CPU_STM32MP153Fxx:
+ case CPU_STM32MP153Dxx:
+ case CPU_STM32MP151Fxx:
+ case CPU_STM32MP151Dxx:
+ return true;
+ default:
+ return id == 1;
+ }
+}
+
+/*
+ * gets OPP parameters (frequency in KHz and voltage in mV) from
+ * an OPP table subnode. Platform HW support capabilities are also checked.
+ * Returns 0 on success and a negative FDT error code on failure.
+ */
+static int stm32mp1_get_opp(u32 cpu_type, ofnode subnode,
+ u32 *freq_khz, u32 *voltage_mv)
+{
+ u32 opp_hw;
+ u64 read_freq_64;
+ u32 read_voltage_32;
+
+ *freq_khz = 0;
+ *voltage_mv = 0;
+
+ opp_hw = ofnode_read_u32_default(subnode, "opp-supported-hw", 0);
+ if (opp_hw)
+ if (!stm32mp1_supports_opp(opp_hw, cpu_type))
+ return -FDT_ERR_BADVALUE;
+
+ read_freq_64 = ofnode_read_u64_default(subnode, "opp-hz", 0) /
+ 1000ULL;
+ read_voltage_32 = ofnode_read_u32_default(subnode, "opp-microvolt", 0) /
+ 1000U;
+
+ if (!read_voltage_32 || !read_freq_64)
+ return -FDT_ERR_NOTFOUND;
+
+ /* Frequency value expressed in KHz must fit on 32 bits */
+ if (read_freq_64 > U32_MAX)
+ return -FDT_ERR_BADVALUE;
+
+ /* Millivolt value must fit on 16 bits */
+ if (read_voltage_32 > U16_MAX)
+ return -FDT_ERR_BADVALUE;
+
+ *freq_khz = (u32)read_freq_64;
+ *voltage_mv = read_voltage_32;
+
+ return 0;
+}
+
+/*
+ * parses OPP table in DT and finds the parameters for the
+ * highest frequency supported by the HW platform.
+ * Returns 0 on success and a negative FDT error code on failure.
+ */
+int stm32mp1_get_max_opp_freq(struct stm32mp1_clk_priv *priv, u64 *freq_hz)
+{
+ ofnode node, subnode;
+ int ret;
+ u32 freq = 0U, voltage = 0U;
+ u32 cpu_type = get_cpu_type();
+
+ node = ofnode_by_compatible(ofnode_null(), "operating-points-v2");
+ if (!ofnode_valid(node))
+ return -FDT_ERR_NOTFOUND;
+
+ ofnode_for_each_subnode(subnode, node) {
+ unsigned int read_freq;
+ unsigned int read_voltage;
+
+ ret = stm32mp1_get_opp(cpu_type, subnode,
+ &read_freq, &read_voltage);
+ if (ret)
+ continue;
+
+ if (read_freq > freq) {
+ freq = read_freq;
+ voltage = read_voltage;
+ }
+ }
+
+ if (!freq || !voltage)
+ return -FDT_ERR_NOTFOUND;
+
+ *freq_hz = (u64)1000U * freq;
+
+ return 0;
+}
+
+static int stm32mp1_pll1_opp(struct stm32mp1_clk_priv *priv, int clksrc,
+ u32 *pllcfg, u32 *fracv)
+{
+ u32 post_divm;
+ u32 input_freq;
+ u64 output_freq;
+ u64 freq;
+ u64 vco;
+ u32 divm, divn, divp, frac;
+ int i, ret;
+ u32 diff;
+ u32 best_diff = U32_MAX;
+
+ /* PLL1 is 1600 */
+ const u32 DIVN_MAX = stm32mp1_pll[PLL_1600].divn_max;
+ const u32 POST_DIVM_MIN = stm32mp1_pll[PLL_1600].refclk_min * 1000000U;
+ const u32 POST_DIVM_MAX = stm32mp1_pll[PLL_1600].refclk_max * 1000000U;
+
+ ret = stm32mp1_get_max_opp_freq(priv, &output_freq);
+ if (ret) {
+ debug("PLL1 OPP configuration not found (%d).\n", ret);
+ return ret;
+ }
+
+ switch (clksrc) {
+ case CLK_PLL12_HSI:
+ input_freq = stm32mp1_clk_get_fixed(priv, _HSI);
+ break;
+ case CLK_PLL12_HSE:
+ input_freq = stm32mp1_clk_get_fixed(priv, _HSE);
+ break;
+ default:
+ return -EINTR;
+ }
+
+ /* Following parameters have always the same value */
+ pllcfg[PLLCFG_Q] = 0;
+ pllcfg[PLLCFG_R] = 0;
+ pllcfg[PLLCFG_O] = PQR(1, 0, 0);
+
+ for (divm = DIVM_MAX; divm >= DIVM_MIN; divm--) {
+ post_divm = (u32)(input_freq / (divm + 1));
+ if (post_divm < POST_DIVM_MIN || post_divm > POST_DIVM_MAX)
+ continue;
+
+ for (divp = DIVP_MIN; divp <= DIVP_MAX; divp++) {
+ freq = output_freq * (divm + 1) * (divp + 1);
+ divn = (u32)((freq / input_freq) - 1);
+ if (divn < DIVN_MIN || divn > DIVN_MAX)
+ continue;
+
+ frac = (u32)(((freq * FRAC_MAX) / input_freq) -
+ ((divn + 1) * FRAC_MAX));
+ /* 2 loops to refine the fractional part */
+ for (i = 2; i != 0; i--) {
+ if (frac > FRAC_MAX)
+ break;
+
+ vco = (post_divm * (divn + 1)) +
+ ((post_divm * (u64)frac) /
+ FRAC_MAX);
+ if (vco < (PLL1600_VCO_MIN / 2) ||
+ vco > (PLL1600_VCO_MAX / 2)) {
+ frac++;
+ continue;
+ }
+ freq = vco / (divp + 1);
+ if (output_freq < freq)
+ diff = (u32)(freq - output_freq);
+ else
+ diff = (u32)(output_freq - freq);
+ if (diff < best_diff) {
+ pllcfg[PLLCFG_M] = divm;
+ pllcfg[PLLCFG_N] = divn;
+ pllcfg[PLLCFG_P] = divp;
+ *fracv = frac;
+
+ if (diff == 0)
+ return 0;
+
+ best_diff = diff;
+ }
+ frac++;
+ }
+ }
+ }
+
+ if (best_diff == U32_MAX)
+ return -1;
+
+ return 0;
+}
+
static void stm32mp1_ls_osc_set(int enable, fdt_addr_t rcc, u32 offset,
u32 mask_on)
{
@@ -1658,9 +1871,12 @@ static int stm32mp1_clktree(struct udevice *dev)
unsigned int clksrc[CLKSRC_NB];
unsigned int clkdiv[CLKDIV_NB];
unsigned int pllcfg[_PLL_NB][PLLCFG_NB];
- ofnode plloff[_PLL_NB];
- int ret, len;
- uint i;
+ unsigned int pllfracv[_PLL_NB];
+ unsigned int pllcsg[_PLL_NB][PLLCSG_NB];
+ bool pllcfg_valid[_PLL_NB];
+ bool pllcsg_set[_PLL_NB];
+ int ret;
+ int i, len;
int lse_css = 0;
const u32 *pkcs_cell;
@@ -1680,16 +1896,43 @@ static int stm32mp1_clktree(struct udevice *dev)
/* check mandatory field in each pll */
for (i = 0; i < _PLL_NB; i++) {
char name[12];
+ ofnode node;
sprintf(name, "st,pll@%d", i);
- plloff[i] = dev_read_subnode(dev, name);
- if (!ofnode_valid(plloff[i]))
- continue;
- ret = ofnode_read_u32_array(plloff[i], "cfg",
- pllcfg[i], PLLCFG_NB);
- if (ret < 0) {
- debug("field cfg invalid: error %d\n", ret);
- return -FDT_ERR_NOTFOUND;
+ node = dev_read_subnode(dev, name);
+ pllcfg_valid[i] = ofnode_valid(node);
+ pllcsg_set[i] = false;
+ if (pllcfg_valid[i]) {
+ debug("DT for PLL %d @ %s\n", i, name);
+ ret = ofnode_read_u32_array(node, "cfg",
+ pllcfg[i], PLLCFG_NB);
+ if (ret < 0) {
+ debug("field cfg invalid: error %d\n", ret);
+ return -FDT_ERR_NOTFOUND;
+ }
+ pllfracv[i] = ofnode_read_u32_default(node, "frac", 0);
+
+ ret = ofnode_read_u32_array(node, "csg", pllcsg[i],
+ PLLCSG_NB);
+ if (!ret) {
+ pllcsg_set[i] = true;
+ } else if (ret != -FDT_ERR_NOTFOUND) {
+ debug("invalid csg node for pll@%d res=%d\n",
+ i, ret);
+ return ret;
+ }
+ } else if (i == _PLL1) {
+ /* use OPP for PLL1 for A7 CPU */
+ debug("DT for PLL %d with OPP\n", i);
+ ret = stm32mp1_pll1_opp(priv,
+ clksrc[CLKSRC_PLL12],
+ pllcfg[i],
+ &pllfracv[i]);
+ if (ret) {
+ debug("PLL %d with OPP error = %d\n", i, ret);
+ return ret;
+ }
+ pllcfg_valid[i] = true;
}
}
@@ -1775,29 +2018,18 @@ static int stm32mp1_clktree(struct udevice *dev)
/* configure and start PLLs */
debug("configure PLLs\n");
for (i = 0; i < _PLL_NB; i++) {
- u32 fracv;
- u32 csg[PLLCSG_NB];
-
- debug("configure PLL %d @ %d\n", i,
- ofnode_to_offset(plloff[i]));
- if (!ofnode_valid(plloff[i]))
+ if (!pllcfg_valid[i])
continue;
-
- fracv = ofnode_read_u32_default(plloff[i], "frac", 0);
- pll_config(priv, i, pllcfg[i], fracv);
- ret = ofnode_read_u32_array(plloff[i], "csg", csg, PLLCSG_NB);
- if (!ret) {
- pll_csg(priv, i, csg);
- } else if (ret != -FDT_ERR_NOTFOUND) {
- debug("invalid csg node for pll@%d res=%d\n", i, ret);
- return ret;
- }
+ debug("configure PLL %d\n", i);
+ pll_config(priv, i, pllcfg[i], pllfracv[i]);
+ if (pllcsg_set[i])
+ pll_csg(priv, i, pllcsg[i]);
pll_start(priv, i);
}
/* wait and start PLLs ouptut when ready */
for (i = 0; i < _PLL_NB; i++) {
- if (!ofnode_valid(plloff[i]))
+ if (!pllcfg_valid[i])
continue;
debug("output PLL %d\n", i);
pll_output(priv, i, pllcfg[i][PLLCFG_O]);
@@ -2047,6 +2279,8 @@ static int stm32mp1_clk_probe(struct udevice *dev)
/* clock tree init is done only one time, before relocation */
if (!(gd->flags & GD_FLG_RELOC))
result = stm32mp1_clktree(dev);
+ if (result)
+ printf("clock tree initialization failed (%d)\n", result);
#endif
#ifndef CONFIG_SPL_BUILD
--
2.17.1
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