On 08/03, Leo Yan wrote: > diff --git a/drivers/clk/hisilicon/clk-hi6220-stub.c b/drivers/clk/hisilicon/clk-hi6220-stub.c > new file mode 100644 > index 0000000..0931666 > --- /dev/null > +++ b/drivers/clk/hisilicon/clk-hi6220-stub.c > @@ -0,0 +1,279 @@ > +/* > + * Hi6220 stub clock driver > + * > + * Copyright (c) 2015 Hisilicon Limited. > + * Copyright (c) 2015 Linaro Limited. > + * > + * Author: Leo Yan <leo.yan@xxxxxxxxxx> > + * > + * 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/clkdev.h> Is this include used? > +#include <linux/clk-provider.h> > +#include <linux/clk.h> Is this include used? > +#include <linux/err.h> > +#include <linux/mfd/syscon.h> > +#include <linux/mailbox_client.h> > +#include <linux/of.h> > +#include <linux/of_device.h> > +#include <linux/regmap.h> > +#include <linux/slab.h> > +#include <linux/kernel.h> > + > +#include <dt-bindings/clock/hi6220-clock.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) We don't need parenthesis around single values in these macros. > + > +#define to_stub_clk(hw) container_of(hw, struct hi6220_stub_clk, hw) > + > +struct hi6220_stub_clk { > + u32 id; > + u32 rate; > + > + 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; > + > + stub_clk->mbox = mbox_request_channel(&stub_clk->cl, 0); Why not request the channel once in probe? > + if (IS_ERR(stub_clk->mbox)) { > + dev_err(stub_clk->dev, "failed get mailbox channel\n"); > + return PTR_ERR(stub_clk->mbox); > + }; > + > + /* 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); > + mbox_free_channel(stub_clk->mbox); > + 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 constrainted frequency */ s/constrainted/constrained/ ? > + 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 */ s/KHz/kHz/ ? > + 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 */ s/KHz/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; > + } > + > + stub_clk->rate = new_rate; Why do we store away the rate? Is this used anywhere? > + > + 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 */ s/KHz/kHz/ ? > + > + switch (stub_clk->id) { > + case HI6220_STUB_ACPU0: > + new_rate = hi6220_acpu_round_freq(stub_clk, new_rate); > + > + /* convert from KHz to Hz */ s/KHz/kHz/ ? > + 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 struct clk_ops hi6220_stub_clk_ops = { const? > + .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; > + > + stub_clk = devm_kzalloc(&pdev->dev, sizeof(*stub_clk), GFP_KERNEL); just use dev? > + 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 = &pdev->dev; just use 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; > + > + init.name = "acpu0"; > + init.ops = &hi6220_stub_clk_ops; > + init.num_parents = 0; > + init.flags = CLK_IS_ROOT; > + > + clk = clk_register(NULL, &stub_clk->hw); why not devm_clk_register? > + if (IS_ERR(clk)) > + return PTR_ERR(clk); > + > + of_clk_add_provider(pdev->dev.of_node, of_clk_src_simple_get, clk); And check this for an error return value? Also, just use dev? > + > + /* 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(&pdev->dev, "Registered clock '%s'\n", init.name); just use dev? > + 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 = of_match_ptr(hi6220_stub_clk_of_match), We can leave off of_match_ptr() here. > + }, > + .probe = hi6220_stub_clk_probe, > +}; -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html