diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/clk/hisilicon/clk-hi6220-stub.c | 276 |
1 files changed, 276 insertions, 0 deletions
diff --git a/drivers/clk/hisilicon/clk-hi6220-stub.c b/drivers/clk/hisilicon/clk-hi6220-stub.c new file mode 100644 index 000000000..329a09214 --- /dev/null +++ b/drivers/clk/hisilicon/clk-hi6220-stub.c @@ -0,0 +1,276 @@ +/* + * Hi6220 stub clock driver + * + * Copyright (c) 2015 Hisilicon Limited. + * Copyright (c) 2015 Linaro Limited. + * + * Author: Leo Yan <leo.yan@linaro.org> + * + * 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-provider.h> +#include <linux/err.h> +#include <linux/kernel.h> +#include <linux/mfd/syscon.h> +#include <linux/mailbox_client.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/regmap.h> + +/* Stub clocks id */ +#define HI6220_STUB_ACPU0 0 +#define HI6220_STUB_ACPU1 1 +#define HI6220_STUB_GPU 2 +#define HI6220_STUB_DDR 5 + +/* Mailbox message */ +#define HI6220_MBOX_MSG_LEN 8 + +#define HI6220_MBOX_FREQ 0xA +#define HI6220_MBOX_CMD_SET 0x3 +#define HI6220_MBOX_OBJ_AP 0x0 + +/* CPU dynamic frequency scaling */ +#define ACPU_DFS_FREQ_MAX 0x1724 +#define ACPU_DFS_CUR_FREQ 0x17CC +#define ACPU_DFS_FLAG 0x1B30 +#define ACPU_DFS_FREQ_REQ 0x1B34 +#define ACPU_DFS_FREQ_LMT 0x1B38 +#define ACPU_DFS_LOCK_FLAG 0xAEAEAEAE + +#define to_stub_clk(hw) container_of(hw, struct hi6220_stub_clk, hw) + +struct hi6220_stub_clk { + u32 id; + + struct device *dev; + struct clk_hw hw; + + struct regmap *dfs_map; + struct mbox_client cl; + struct mbox_chan *mbox; +}; + +struct hi6220_mbox_msg { + unsigned char type; + unsigned char cmd; + unsigned char obj; + unsigned char src; + unsigned char para[4]; +}; + +union hi6220_mbox_data { + unsigned int data[HI6220_MBOX_MSG_LEN]; + struct hi6220_mbox_msg msg; +}; + +static unsigned int hi6220_acpu_get_freq(struct hi6220_stub_clk *stub_clk) +{ + unsigned int freq; + + regmap_read(stub_clk->dfs_map, ACPU_DFS_CUR_FREQ, &freq); + return freq; +} + +static int hi6220_acpu_set_freq(struct hi6220_stub_clk *stub_clk, + unsigned int freq) +{ + union hi6220_mbox_data data; + + /* set the frequency in sram */ + regmap_write(stub_clk->dfs_map, ACPU_DFS_FREQ_REQ, freq); + + /* compound mailbox message */ + data.msg.type = HI6220_MBOX_FREQ; + data.msg.cmd = HI6220_MBOX_CMD_SET; + data.msg.obj = HI6220_MBOX_OBJ_AP; + data.msg.src = HI6220_MBOX_OBJ_AP; + + mbox_send_message(stub_clk->mbox, &data); + return 0; +} + +static int hi6220_acpu_round_freq(struct hi6220_stub_clk *stub_clk, + unsigned int freq) +{ + unsigned int limit_flag, limit_freq = UINT_MAX; + unsigned int max_freq; + + /* check the constrained frequency */ + regmap_read(stub_clk->dfs_map, ACPU_DFS_FLAG, &limit_flag); + if (limit_flag == ACPU_DFS_LOCK_FLAG) + regmap_read(stub_clk->dfs_map, ACPU_DFS_FREQ_LMT, &limit_freq); + + /* check the supported maximum frequency */ + regmap_read(stub_clk->dfs_map, ACPU_DFS_FREQ_MAX, &max_freq); + + /* calculate the real maximum frequency */ + max_freq = min(max_freq, limit_freq); + + if (WARN_ON(freq > max_freq)) + freq = max_freq; + + return freq; +} + +static unsigned long hi6220_stub_clk_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + u32 rate = 0; + struct hi6220_stub_clk *stub_clk = to_stub_clk(hw); + + switch (stub_clk->id) { + case HI6220_STUB_ACPU0: + rate = hi6220_acpu_get_freq(stub_clk); + + /* convert from kHz to Hz */ + rate *= 1000; + break; + + default: + dev_err(stub_clk->dev, "%s: un-supported clock id %d\n", + __func__, stub_clk->id); + break; + } + + return rate; +} + +static int hi6220_stub_clk_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct hi6220_stub_clk *stub_clk = to_stub_clk(hw); + unsigned long new_rate = rate / 1000; /* kHz */ + int ret = 0; + + switch (stub_clk->id) { + case HI6220_STUB_ACPU0: + ret = hi6220_acpu_set_freq(stub_clk, new_rate); + if (ret < 0) + return ret; + + break; + + default: + dev_err(stub_clk->dev, "%s: un-supported clock id %d\n", + __func__, stub_clk->id); + break; + } + + pr_debug("%s: set rate=%ldkHz\n", __func__, new_rate); + return ret; +} + +static long hi6220_stub_clk_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + struct hi6220_stub_clk *stub_clk = to_stub_clk(hw); + unsigned long new_rate = rate / 1000; /* kHz */ + + switch (stub_clk->id) { + case HI6220_STUB_ACPU0: + new_rate = hi6220_acpu_round_freq(stub_clk, new_rate); + + /* convert from kHz to Hz */ + new_rate *= 1000; + break; + + default: + dev_err(stub_clk->dev, "%s: un-supported clock id %d\n", + __func__, stub_clk->id); + break; + } + + return new_rate; +} + +static const struct clk_ops hi6220_stub_clk_ops = { + .recalc_rate = hi6220_stub_clk_recalc_rate, + .round_rate = hi6220_stub_clk_round_rate, + .set_rate = hi6220_stub_clk_set_rate, +}; + +static int hi6220_stub_clk_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct clk_init_data init; + struct hi6220_stub_clk *stub_clk; + struct clk *clk; + struct device_node *np = pdev->dev.of_node; + int ret; + + stub_clk = devm_kzalloc(dev, sizeof(*stub_clk), GFP_KERNEL); + if (!stub_clk) + return -ENOMEM; + + stub_clk->dfs_map = syscon_regmap_lookup_by_phandle(np, + "hisilicon,hi6220-clk-sram"); + if (IS_ERR(stub_clk->dfs_map)) { + dev_err(dev, "failed to get sram regmap\n"); + return PTR_ERR(stub_clk->dfs_map); + } + + stub_clk->hw.init = &init; + stub_clk->dev = dev; + stub_clk->id = HI6220_STUB_ACPU0; + + /* Use mailbox client with blocking mode */ + stub_clk->cl.dev = dev; + stub_clk->cl.tx_done = NULL; + stub_clk->cl.tx_block = true; + stub_clk->cl.tx_tout = 500; + stub_clk->cl.knows_txdone = false; + + /* Allocate mailbox channel */ + stub_clk->mbox = mbox_request_channel(&stub_clk->cl, 0); + if (IS_ERR(stub_clk->mbox)) { + dev_err(dev, "failed get mailbox channel\n"); + return PTR_ERR(stub_clk->mbox); + } + + init.name = "acpu0"; + init.ops = &hi6220_stub_clk_ops; + init.num_parents = 0; + init.flags = 0; + + clk = devm_clk_register(dev, &stub_clk->hw); + if (IS_ERR(clk)) + return PTR_ERR(clk); + + ret = of_clk_add_provider(np, of_clk_src_simple_get, clk); + if (ret) { + dev_err(dev, "failed to register OF clock provider\n"); + return ret; + } + + /* initialize buffer to zero */ + regmap_write(stub_clk->dfs_map, ACPU_DFS_FLAG, 0x0); + regmap_write(stub_clk->dfs_map, ACPU_DFS_FREQ_REQ, 0x0); + regmap_write(stub_clk->dfs_map, ACPU_DFS_FREQ_LMT, 0x0); + + dev_dbg(dev, "Registered clock '%s'\n", init.name); + return 0; +} + +static const struct of_device_id hi6220_stub_clk_of_match[] = { + { .compatible = "hisilicon,hi6220-stub-clk", }, + {} +}; + +static struct platform_driver hi6220_stub_clk_driver = { + .driver = { + .name = "hi6220-stub-clk", + .of_match_table = hi6220_stub_clk_of_match, + }, + .probe = hi6220_stub_clk_probe, +}; + +static int __init hi6220_stub_clk_init(void) +{ + return platform_driver_register(&hi6220_stub_clk_driver); +} +subsys_initcall(hi6220_stub_clk_init); |