ARM: DRA7: Fixup DSPEVE, IVA and GPU clock frequencies based on OPP

This patch adds support to update the device-tree blob to adjust the
DSP and IVA DPLL clocks pertinent to the selected OPP choice, with
the default being OPP_NOM. The voltage settings are done in u-boot,
but the actual clock configuration itself is done in kernel because
of the following reasons:
1. SoC definition constraints us to NOT to do dynamic voltage
   scaling ever after the initial avs0 setting in bootloader
   - so the voltage must be set in bootloader.
2. The voltage level must be set even if the IP blocks like
   GPU/DSP are unused.
3. The IVA, GPU and DSP DPLLs are not essential for u-boot functionality,
   and similar DPLL clock configuration code has been cleaned up in
   v2014.10 u-boot release. See commit, 02c41535b6 ("ARM: OMAP4/5:
   Remove dead code against CONFIG_SYS_CLOCKS_ENABLE_ALL").

The non-essential DPLLs are configured within the kernel during
the clock init step when parsing the device tree and creating
the clock devices. This approach meets both the u-boot and kernel
needs.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Subhajit Paul <subhajit_paul@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

arch/arm/mach-omap2/omap5/fdt.c

@@ -266,6 +266,141 @@ static void ft_hs_fixups(void *fdt, bd_t *bd)
 }
 #endif /* #ifdef CONFIG_TI_SECURE_DEVICE */
 
+#if defined(CONFIG_TARGET_DRA7XX_EVM) || defined(CONFIG_TARGET_AM57XX_EVM)
+#define OPP_DSP_CLK_NUM	3
+#define OPP_IVA_CLK_NUM	2
+#define OPP_GPU_CLK_NUM	2
+
+const char *dra7_opp_dsp_clk_names[OPP_DSP_CLK_NUM] = {
+	"dpll_dsp_ck",
+	"dpll_dsp_m2_ck",
+	"dpll_dsp_m3x2_ck",
+};
+
+const char *dra7_opp_iva_clk_names[OPP_IVA_CLK_NUM] = {
+	"dpll_iva_ck",
+	"dpll_iva_m2_ck",
+};
+
+const char *dra7_opp_gpu_clk_names[OPP_GPU_CLK_NUM] = {
+	"dpll_gpu_ck",
+	"dpll_gpu_m2_ck",
+};
+
+/* DSPEVE voltage domain */
+u32 dra7_opp_dsp_clk_rates[NUM_OPPS][OPP_DSP_CLK_NUM] = {
+	{}, /*OPP_LOW */
+	{600000000, 600000000, 400000000}, /* OPP_NOM */
+	{700000000, 700000000, 466666667}, /* OPP_OD */
+	{750000000, 750000000, 500000000}, /* OPP_HIGH */
+};
+
+/* IVA voltage domain */
+u32 dra7_opp_iva_clk_rates[NUM_OPPS][OPP_IVA_CLK_NUM] = {
+	{}, /* OPP_LOW */
+	{1165000000, 388333334}, /* OPP_NOM */
+	{860000000, 430000000}, /* OPP_OD */
+	{1064000000, 532000000}, /* OPP_HIGH */
+};
+
+/* GPU voltage domain */
+u32 dra7_opp_gpu_clk_rates[NUM_OPPS][OPP_GPU_CLK_NUM] = {
+	{}, /* OPP_LOW */
+	{1277000000, 425666667}, /* OPP_NOM */
+	{1000000000, 500000000}, /* OPP_OD */
+	{1064000000, 532000000}, /* OPP_HIGH */
+};
+
+static int ft_fixup_clocks(void *fdt, const char **names, u32 *rates, int num)
+{
+	int offs, node_offs, ret, i;
+	uint32_t phandle;
+
+	offs = fdt_path_offset(fdt, "/ocp/l4@4a000000/cm_core_aon@5000/clocks");
+	if (offs < 0) {
+		debug("Could not find cm_core_aon clocks node path offset : %s\n",
+		      fdt_strerror(offs));
+		return offs;
+	}
+
+	for (i = 0; i < num; i++) {
+		node_offs = fdt_subnode_offset(fdt, offs, names[i]);
+		if (node_offs < 0) {
+			debug("Could not find clock sub-node %s: %s\n",
+			      names[i], fdt_strerror(node_offs));
+			return offs;
+		}
+
+		phandle = fdt_get_phandle(fdt, node_offs);
+		if (!phandle) {
+			debug("Could not find phandle for clock %s\n",
+			      names[i]);
+			return -1;
+		}
+
+		ret = fdt_setprop_u32(fdt, node_offs, "assigned-clocks",
+				      phandle);
+		if (ret < 0) {
+			debug("Could not add assigned-clocks property to clock node %s: %s\n",
+			      names[i], fdt_strerror(ret));
+			return ret;
+		}
+
+		ret = fdt_setprop_u32(fdt, node_offs, "assigned-clock-rates",
+				      rates[i]);
+		if (ret < 0) {
+			debug("Could not add assigned-clock-rates property to clock node %s: %s\n",
+			      names[i], fdt_strerror(ret));
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static void ft_opp_clock_fixups(void *fdt, bd_t *bd)
+{
+	const char **clk_names;
+	u32 *clk_rates;
+	int ret;
+
+	if (!is_dra72x() && !is_dra7xx())
+		return;
+
+	/* fixup DSP clocks */
+	clk_names = dra7_opp_dsp_clk_names;
+	clk_rates = dra7_opp_dsp_clk_rates[get_voltrail_opp(VOLT_EVE)];
+	ret = ft_fixup_clocks(fdt, clk_names, clk_rates, OPP_DSP_CLK_NUM);
+	if (ret) {
+		printf("ft_fixup_clocks failed for DSP voltage domain: %s\n",
+		       fdt_strerror(ret));
+		return;
+	}
+
+	/* fixup IVA clocks */
+	clk_names = dra7_opp_iva_clk_names;
+	clk_rates = dra7_opp_iva_clk_rates[get_voltrail_opp(VOLT_IVA)];
+	ret = ft_fixup_clocks(fdt, clk_names, clk_rates, OPP_IVA_CLK_NUM);
+	if (ret) {
+		printf("ft_fixup_clocks failed for IVA voltage domain: %s\n",
+		       fdt_strerror(ret));
+		return;
+	}
+
+	/* fixup GPU clocks */
+	clk_names = dra7_opp_gpu_clk_names;
+	clk_rates = dra7_opp_gpu_clk_rates[get_voltrail_opp(VOLT_GPU)];
+	ret = ft_fixup_clocks(fdt, clk_names, clk_rates, OPP_GPU_CLK_NUM);
+	if (ret) {
+		printf("ft_fixup_clocks failed for GPU voltage domain: %s\n",
+		       fdt_strerror(ret));
+		return;
+	}
+}
+#else
+static void ft_opp_clock_fixups(void *fdt, bd_t *bd) { }
+#endif /* CONFIG_TARGET_DRA7XX_EVM || CONFIG_TARGET_AM57XX_EVM */
+
 /*
  * Place for general cpu/SoC FDT fixups. Board specific
  * fixups should remain in the board files which is where
@@ -274,4 +409,5 @@ static void ft_hs_fixups(void *fdt, bd_t *bd)
 void ft_cpu_setup(void *fdt, bd_t *bd)
 {
 	ft_hs_fixups(fdt, bd);
+	ft_opp_clock_fixups(fdt, bd);
 }