--- /dev/null
+/*
+ * JZ4780 NAND/external memory controller (NEMC)
+ *
+ * Copyright (c) 2015 Imagination Technologies
+ * Author: Alex Smith <alex@alex-smith.me.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/init.h>
+#include <linux/math64.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include <linux/jz4780-nemc.h>
+
+#define NEMC_SMCRn(n) (0x14 + (((n) - 1) * 4))
+#define NEMC_NFCSR 0x50
+
+#define NEMC_SMCR_SMT BIT(0)
+#define NEMC_SMCR_BW_SHIFT 6
+#define NEMC_SMCR_BW_MASK (0x3 << NEMC_SMCR_BW_SHIFT)
+#define NEMC_SMCR_BW_8 (0 << 6)
+#define NEMC_SMCR_TAS_SHIFT 8
+#define NEMC_SMCR_TAS_MASK (0xf << NEMC_SMCR_TAS_SHIFT)
+#define NEMC_SMCR_TAH_SHIFT 12
+#define NEMC_SMCR_TAH_MASK (0xf << NEMC_SMCR_TAH_SHIFT)
+#define NEMC_SMCR_TBP_SHIFT 16
+#define NEMC_SMCR_TBP_MASK (0xf << NEMC_SMCR_TBP_SHIFT)
+#define NEMC_SMCR_TAW_SHIFT 20
+#define NEMC_SMCR_TAW_MASK (0xf << NEMC_SMCR_TAW_SHIFT)
+#define NEMC_SMCR_TSTRV_SHIFT 24
+#define NEMC_SMCR_TSTRV_MASK (0x3f << NEMC_SMCR_TSTRV_SHIFT)
+
+#define NEMC_NFCSR_NFEn(n) BIT(((n) - 1) << 1)
+#define NEMC_NFCSR_NFCEn(n) BIT((((n) - 1) << 1) + 1)
+#define NEMC_NFCSR_TNFEn(n) BIT(16 + (n) - 1)
+
+struct jz4780_nemc {
+ spinlock_t lock;
+ struct device *dev;
+ void __iomem *base;
+ struct clk *clk;
+ uint32_t clk_period;
+ unsigned long banks_present;
+};
+
+/**
+ * jz4780_nemc_num_banks() - count the number of banks referenced by a device
+ * @dev: device to count banks for, must be a child of the NEMC.
+ *
+ * Return: The number of unique NEMC banks referred to by the specified NEMC
+ * child device. Unique here means that a device that references the same bank
+ * multiple times in the its "reg" property will only count once.
+ */
+unsigned int jz4780_nemc_num_banks(struct device *dev)
+{
+ const __be32 *prop;
+ unsigned int bank, count = 0;
+ unsigned long referenced = 0;
+ int i = 0;
+
+ while ((prop = of_get_address(dev->of_node, i++, NULL, NULL))) {
+ bank = of_read_number(prop, 1);
+ if (!(referenced & BIT(bank))) {
+ referenced |= BIT(bank);
+ count++;
+ }
+ }
+
+ return count;
+}
+EXPORT_SYMBOL(jz4780_nemc_num_banks);
+
+/**
+ * jz4780_nemc_set_type() - set the type of device connected to a bank
+ * @dev: child device of the NEMC.
+ * @bank: bank number to configure.
+ * @type: type of device connected to the bank.
+ */
+void jz4780_nemc_set_type(struct device *dev, unsigned int bank,
+ enum jz4780_nemc_bank_type type)
+{
+ struct jz4780_nemc *nemc = dev_get_drvdata(dev->parent);
+ uint32_t nfcsr;
+
+ nfcsr = readl(nemc->base + NEMC_NFCSR);
+
+ /* TODO: Support toggle NAND devices. */
+ switch (type) {
+ case JZ4780_NEMC_BANK_SRAM:
+ nfcsr &= ~(NEMC_NFCSR_TNFEn(bank) | NEMC_NFCSR_NFEn(bank));
+ break;
+ case JZ4780_NEMC_BANK_NAND:
+ nfcsr &= ~NEMC_NFCSR_TNFEn(bank);
+ nfcsr |= NEMC_NFCSR_NFEn(bank);
+ break;
+ }
+
+ writel(nfcsr, nemc->base + NEMC_NFCSR);
+}
+EXPORT_SYMBOL(jz4780_nemc_set_type);
+
+/**
+ * jz4780_nemc_assert() - (de-)assert a NAND device's chip enable pin
+ * @dev: child device of the NEMC.
+ * @bank: bank number of device.
+ * @assert: whether the chip enable pin should be asserted.
+ *
+ * (De-)asserts the chip enable pin for the NAND device connected to the
+ * specified bank.
+ */
+void jz4780_nemc_assert(struct device *dev, unsigned int bank, bool assert)
+{
+ struct jz4780_nemc *nemc = dev_get_drvdata(dev->parent);
+ uint32_t nfcsr;
+
+ nfcsr = readl(nemc->base + NEMC_NFCSR);
+
+ if (assert)
+ nfcsr |= NEMC_NFCSR_NFCEn(bank);
+ else
+ nfcsr &= ~NEMC_NFCSR_NFCEn(bank);
+
+ writel(nfcsr, nemc->base + NEMC_NFCSR);
+}
+EXPORT_SYMBOL(jz4780_nemc_assert);
+
+static uint32_t jz4780_nemc_clk_period(struct jz4780_nemc *nemc)
+{
+ unsigned long rate;
+
+ rate = clk_get_rate(nemc->clk);
+ if (!rate)
+ return 0;
+
+ /* Return in picoseconds. */
+ return div64_ul(1000000000000ull, rate);
+}
+
+static uint32_t jz4780_nemc_ns_to_cycles(struct jz4780_nemc *nemc, uint32_t ns)
+{
+ return ((ns * 1000) + nemc->clk_period - 1) / nemc->clk_period;
+}
+
+static bool jz4780_nemc_configure_bank(struct jz4780_nemc *nemc,
+ unsigned int bank,
+ struct device_node *node)
+{
+ uint32_t smcr, val, cycles;
+
+ /*
+ * Conversion of tBP and tAW cycle counts to values supported by the
+ * hardware (round up to the next supported value).
+ */
+ static const uint32_t convert_tBP_tAW[] = {
+ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
+
+ /* 11 - 12 -> 12 cycles */
+ 11, 11,
+
+ /* 13 - 15 -> 15 cycles */
+ 12, 12, 12,
+
+ /* 16 - 20 -> 20 cycles */
+ 13, 13, 13, 13, 13,
+
+ /* 21 - 25 -> 25 cycles */
+ 14, 14, 14, 14, 14,
+
+ /* 26 - 31 -> 31 cycles */
+ 15, 15, 15, 15, 15, 15
+ };
+
+ smcr = readl(nemc->base + NEMC_SMCRn(bank));
+ smcr &= ~NEMC_SMCR_SMT;
+
+ if (!of_property_read_u32(node, "ingenic,nemc-bus-width", &val)) {
+ smcr &= ~NEMC_SMCR_BW_MASK;
+ switch (val) {
+ case 8:
+ smcr |= NEMC_SMCR_BW_8;
+ break;
+ default:
+ /*
+ * Earlier SoCs support a 16 bit bus width (the 4780
+ * does not), until those are properly supported, error.
+ */
+ dev_err(nemc->dev, "unsupported bus width: %u\n", val);
+ return false;
+ }
+ }
+
+ if (of_property_read_u32(node, "ingenic,nemc-tAS", &val) == 0) {
+ smcr &= ~NEMC_SMCR_TAS_MASK;
+ cycles = jz4780_nemc_ns_to_cycles(nemc, val);
+ if (cycles > 15) {
+ dev_err(nemc->dev, "tAS %u is too high (%u cycles)\n",
+ val, cycles);
+ return false;
+ }
+
+ smcr |= cycles << NEMC_SMCR_TAS_SHIFT;
+ }
+
+ if (of_property_read_u32(node, "ingenic,nemc-tAH", &val) == 0) {
+ smcr &= ~NEMC_SMCR_TAH_MASK;
+ cycles = jz4780_nemc_ns_to_cycles(nemc, val);
+ if (cycles > 15) {
+ dev_err(nemc->dev, "tAH %u is too high (%u cycles)\n",
+ val, cycles);
+ return false;
+ }
+
+ smcr |= cycles << NEMC_SMCR_TAH_SHIFT;
+ }
+
+ if (of_property_read_u32(node, "ingenic,nemc-tBP", &val) == 0) {
+ smcr &= ~NEMC_SMCR_TBP_MASK;
+ cycles = jz4780_nemc_ns_to_cycles(nemc, val);
+ if (cycles > 31) {
+ dev_err(nemc->dev, "tBP %u is too high (%u cycles)\n",
+ val, cycles);
+ return false;
+ }
+
+ smcr |= convert_tBP_tAW[cycles] << NEMC_SMCR_TBP_SHIFT;
+ }
+
+ if (of_property_read_u32(node, "ingenic,nemc-tAW", &val) == 0) {
+ smcr &= ~NEMC_SMCR_TAW_MASK;
+ cycles = jz4780_nemc_ns_to_cycles(nemc, val);
+ if (cycles > 31) {
+ dev_err(nemc->dev, "tAW %u is too high (%u cycles)\n",
+ val, cycles);
+ return false;
+ }
+
+ smcr |= convert_tBP_tAW[cycles] << NEMC_SMCR_TAW_SHIFT;
+ }
+
+ if (of_property_read_u32(node, "ingenic,nemc-tSTRV", &val) == 0) {
+ smcr &= ~NEMC_SMCR_TSTRV_MASK;
+ cycles = jz4780_nemc_ns_to_cycles(nemc, val);
+ if (cycles > 63) {
+ dev_err(nemc->dev, "tSTRV %u is too high (%u cycles)\n",
+ val, cycles);
+ return false;
+ }
+
+ smcr |= cycles << NEMC_SMCR_TSTRV_SHIFT;
+ }
+
+ writel(smcr, nemc->base + NEMC_SMCRn(bank));
+ return true;
+}
+
+static int jz4780_nemc_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct jz4780_nemc *nemc;
+ struct resource *res;
+ struct device_node *child;
+ const __be32 *prop;
+ unsigned int bank;
+ unsigned long referenced;
+ int i, ret;
+
+ nemc = devm_kzalloc(dev, sizeof(*nemc), GFP_KERNEL);
+ if (!nemc)
+ return -ENOMEM;
+
+ spin_lock_init(&nemc->lock);
+ nemc->dev = dev;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ nemc->base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(nemc->base)) {
+ dev_err(dev, "failed to get I/O memory\n");
+ return PTR_ERR(nemc->base);
+ }
+
+ writel(0, nemc->base + NEMC_NFCSR);
+
+ nemc->clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(nemc->clk)) {
+ dev_err(dev, "failed to get clock\n");
+ return PTR_ERR(nemc->clk);
+ }
+
+ ret = clk_prepare_enable(nemc->clk);
+ if (ret) {
+ dev_err(dev, "failed to enable clock: %d\n", ret);
+ return ret;
+ }
+
+ nemc->clk_period = jz4780_nemc_clk_period(nemc);
+ if (!nemc->clk_period) {
+ dev_err(dev, "failed to calculate clock period\n");
+ clk_disable_unprepare(nemc->clk);
+ return -EINVAL;
+ }
+
+ /*
+ * Iterate over child devices, check that they do not conflict with
+ * each other, and register child devices for them. If a child device
+ * has invalid properties, it is ignored and no platform device is
+ * registered for it.
+ */
+ for_each_child_of_node(nemc->dev->of_node, child) {
+ referenced = 0;
+ i = 0;
+ while ((prop = of_get_address(child, i++, NULL, NULL))) {
+ bank = of_read_number(prop, 1);
+ if (bank < 1 || bank >= JZ4780_NEMC_NUM_BANKS) {
+ dev_err(nemc->dev,
+ "%s requests invalid bank %u\n",
+ child->full_name, bank);
+
+ /* Will continue the outer loop below. */
+ referenced = 0;
+ break;
+ }
+
+ referenced |= BIT(bank);
+ }
+
+ if (!referenced) {
+ dev_err(nemc->dev, "%s has no addresses\n",
+ child->full_name);
+ continue;
+ } else if (nemc->banks_present & referenced) {
+ dev_err(nemc->dev, "%s conflicts with another node\n",
+ child->full_name);
+ continue;
+ }
+
+ /* Configure bank parameters. */
+ for_each_set_bit(bank, &referenced, JZ4780_NEMC_NUM_BANKS) {
+ if (!jz4780_nemc_configure_bank(nemc, bank, child)) {
+ referenced = 0;
+ break;
+ }
+ }
+
+ if (referenced) {
+ if (of_platform_device_create(child, NULL, nemc->dev))
+ nemc->banks_present |= referenced;
+ }
+ }
+
+ platform_set_drvdata(pdev, nemc);
+ dev_info(dev, "JZ4780 NEMC initialised\n");
+ return 0;
+}
+
+static int jz4780_nemc_remove(struct platform_device *pdev)
+{
+ struct jz4780_nemc *nemc = platform_get_drvdata(pdev);
+
+ clk_disable_unprepare(nemc->clk);
+ return 0;
+}
+
+static const struct of_device_id jz4780_nemc_dt_match[] = {
+ { .compatible = "ingenic,jz4780-nemc" },
+ {},
+};
+
+static struct platform_driver jz4780_nemc_driver = {
+ .probe = jz4780_nemc_probe,
+ .remove = jz4780_nemc_remove,
+ .driver = {
+ .name = "jz4780-nemc",
+ .of_match_table = of_match_ptr(jz4780_nemc_dt_match),
+ },
+};
+
+static int __init jz4780_nemc_init(void)
+{
+ return platform_driver_register(&jz4780_nemc_driver);
+}
+subsys_initcall(jz4780_nemc_init);
Code Review / kvmfornfv.git / blobdiff