mc-utils: Update driver so as to support multiple SOCs

Current mc-utils driver is specific to T234 without any support for
extending it to future SOCs. Add such support so that it can be easily
extended for future chips.
- Create a struct of function pointers of all present operations
- Set these function pointers as per SOCs

Bug 4090660

Change-Id: I93e9da987bce1e563eb03aeeb0ac8bcb9da48023
Signed-off-by: Ketan Patil <ketanp@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/2911894
Reviewed-by: Jonathan Hunter <jonathanh@nvidia.com>
Reviewed-by: Sachin Nikam <snikam@nvidia.com>
GVS: Gerrit_Virtual_Submit <buildbot_gerritrpt@nvidia.com>

drivers/platform/tegra/mc-utils/mc-utils.c

@@ -82,6 +82,7 @@ static struct emc_params emc_param;
 static u32 ch_num;
 
 static enum dram_types dram_type;
+static struct mc_utils_ops *ops;
 
 static unsigned long freq_to_bw(unsigned long freq)
 {
@@ -107,21 +108,37 @@ static unsigned long bw_to_freq(unsigned long bw)
 	return (bw + CH_4_BYTES_PER_CLK - 1) / CH_4_BYTES_PER_CLK;
 }
 
-unsigned long emc_freq_to_bw(unsigned long freq)
+static unsigned long emc_freq_to_bw_t23x(unsigned long freq)
 {
 	return freq_to_bw(freq);
 }
+
+unsigned long emc_freq_to_bw(unsigned long freq)
+{
+	return ops->emc_freq_to_bw(freq);
+}
 EXPORT_SYMBOL(emc_freq_to_bw);
 
-unsigned long emc_bw_to_freq(unsigned long bw)
+static unsigned long emc_bw_to_freq_t23x(unsigned long bw)
 {
 	return bw_to_freq(bw);
 }
+
+unsigned long emc_bw_to_freq(unsigned long bw)
+{
+	return ops->emc_bw_to_freq(bw);
+}
 EXPORT_SYMBOL(emc_bw_to_freq);
 
+
+static u8 get_dram_num_channels_t23x(void)
+{
+	return ch_num;
+}
+
 u8 get_dram_num_channels(void)
 {
-	return ch_num;
+	return ops->get_dram_num_channels();
 }
 EXPORT_SYMBOL(get_dram_num_channels);
 
@@ -129,7 +146,7 @@ EXPORT_SYMBOL(get_dram_num_channels);
  *
  * Return: MC clock in MHz
 */
-unsigned long dram_clk_to_mc_clk(unsigned long dram_clk)
+static unsigned long dram_clk_to_mc_clk_t23x(unsigned long dram_clk)
 {
 	unsigned long mc_clk;
 
@@ -139,6 +156,11 @@ unsigned long dram_clk_to_mc_clk(unsigned long dram_clk)
 		mc_clk = (dram_clk + BR8_MODE - 1) / BR8_MODE;
 	return mc_clk;
 }
+
+unsigned long dram_clk_to_mc_clk(unsigned long dram_clk)
+{
+	return ops->dram_clk_to_mc_clk(dram_clk);
+}
 EXPORT_SYMBOL(dram_clk_to_mc_clk);
 
 static void set_dram_type(void)
@@ -261,10 +283,15 @@ static void set_dram_type(void)
 	}
 }
 
-enum dram_types tegra_dram_types(void)
+static enum dram_types tegra_dram_types_t23x(void)
 {
 	return dram_type;
 }
+
+enum dram_types tegra_dram_types(void)
+{
+	return ops->tegra_dram_types();
+}
 EXPORT_SYMBOL(tegra_dram_types);
 
 #if defined(CONFIG_DEBUG_FS)
@@ -300,7 +327,16 @@ static u32 get_dram_dt_prop(struct device_node *np, const char *prop)
 	return val;
 }
 
-static int __init tegra_mc_utils_init(void)
+static struct mc_utils_ops mc_utils_t23x_ops = {
+	.emc_freq_to_bw = emc_freq_to_bw_t23x,
+	.emc_bw_to_freq = emc_bw_to_freq_t23x,
+	.tegra_dram_types = tegra_dram_types_t23x,
+	.get_dram_num_channels = get_dram_num_channels_t23x,
+	.dram_clk_to_mc_clk = dram_clk_to_mc_clk_t23x,
+};
+
+
+static int __init tegra_mc_utils_init_t23x(void)
 {
 	u32 dram, ch, ecc, rank;
 	void __iomem *emc_base;
@@ -354,6 +390,16 @@ static int __init tegra_mc_utils_init(void)
 #endif
 	return 0;
 }
+
+static int __init tegra_mc_utils_init(void)
+{
+	if (of_machine_is_compatible("nvidia,tegra234")) {
+		ops = &mc_utils_t23x_ops;
+		return tegra_mc_utils_init_t23x();
+	}
+	pr_err("mc-utils: Not able to find SOC DT node\n");
+	return -ENODEV;
+}
 module_init(tegra_mc_utils_init);
 
 static void __exit tegra_mc_utils_exit(void)

include/linux/platform/tegra/mc_utils.h

@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
-// Copyright (c) 2022, NVIDIA CORPORATION, All rights reserved.
+// Copyright (c) 2022-2023, NVIDIA CORPORATION. All rights reserved.
 
 #ifndef __TEGRA_MC_UTILS_H
 #define __TEGRA_MC_UTILS_H
@@ -32,6 +32,14 @@ enum dram_types {
 	DRAM_TYPE_LPDDR4_4CH_2RANK,
 };
 
+struct mc_utils_ops {
+	unsigned long (*emc_freq_to_bw)(unsigned long freq);
+	unsigned long (*emc_bw_to_freq)(unsigned long bw);
+	enum dram_types (*tegra_dram_types)(void);
+	u8 (*get_dram_num_channels)(void);
+	unsigned long (*dram_clk_to_mc_clk)(unsigned long dram_clk);
+};
+
 /*
  * Utility API to convert the given frequency to Bandwidth.
  *